# Pneumo-hydraulic Tensioner OPINIONS



## sciroccohal (May 4, 2005)

Guys; 
Conditions; 2000 TTQ 1.8T ATC 180 hp engine BONE STOCK 
I'm unimpressed with this tensioner set-up.:screwy: Audi's Engineering 'C' team obviously designed it. 
I have the second set (tensioner and pulley assy), in the car in *7500 miles.* 
The first tensioner did not fail. 
The second one, (recommended to replace with timing belt), is *not tensioning* to my satisfaction. 
The covers are all removed and will stay removed. 

The belt is loose. The tensioner can be pulled up by hand and THEN will maintain adequate tension, for a day. 
I do not think all the pre-load pressure in the cylinder is lost...it just doesn't push up hard enough on the pulley lever cam. 
It is not leaking nor has it leaked. 

This is a PIA. 

*Consequences are disasterous!* 

These are Genuine Audi parts. 

Questions. 1. Is there a manual type of tensioner assembly available, similar to the Mk1-Mk2 arrangement, with a cam-type tensioner that can be set with a lock nut??? 
2. what the heck is wrong with the brand new one I put in ANALLY? No I didn't use my butt to put it in! LOL 

Any opinions? stories, observations. 

Thanks.


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## Doooglasss (Aug 28, 2009)

Yes integrated engineering sells a kit to use the mk2 8/16v manual tensioner setup.

The kit contains a snazzy guide pulley that I'm not sure is necessary and a spacer for the tensioner - which I know is necessary. You could alternatively buy a $15 manual tensioner and make a spacer, buy a stud and a lock nut.

http://forums.vwvortex.com/showthre...ioner-Solution-from-INTEGRATED-ENGINEERING!**


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## 20v master (May 7, 2009)

If it was as loose as you describe, you'd be throwing a cam to crank correlation code. I've never had an issue with the hydraulic tensioner. Change it on time and forget about it. That said, all the cool kids have manual tensioners, but that's your choice.


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## Doooglasss (Aug 28, 2009)

20v master said:


> If it was as loose as you describe, you'd be throwing a cam to crank correlation code. I've never had an issue with the hydraulic tensioner. Change it on time and forget about it. That said, all the cool kids have manual tensioners, but that's your choice.


 Yep- I was a cool kid and then saw the light. Now I'm a nerd again.

edit my earlier post: it's pretty cheap from the IE site: http://www.intengineering.com/integ...-1-8t-manual-timing-belt-tensioner-kit-w-pump


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## 20v master (May 7, 2009)

DougLoBue said:


> Yep- I was a cool kid and then saw the light. Now I'm a nerd again.
> 
> edit my earlier post: it's pretty cheap from the IE site: http://www.intengineering.com/integ...-1-8t-manual-timing-belt-tensioner-kit-w-pump


 How often do you adjust a manual tensioner? More often than once ever two years, IF you drive over 30K miles a year? Hydraulic FTW!


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## sciroccohal (May 4, 2005)

*Thanks, keep em coming!*

I'm a master at the Mk1 tensioners...set up once...then fergeddaboudit! 

My current theory is the pulley itself is dragging/catching, and not being 'overcome' by the tensioning rod. 

Every day I have to reach in there and galumph (new technical term) up on the flat cam tensioner plate until the belt tightens again. 

When 'loose' it's loose enough to skip a tooth! 

In mk 1's and two's the tensioning procedure is to twist the belt JUST 90° at that point your fingers should HURT! 

*This is far looser than that.*:facepalm: 

Ps as far as the cleanest eng compt thread goes....that would be me. The car is as NEW 
42k miles original in climate controlled storage. Even dust flees my presence! LOL:thumbup: 

Thanks guys!


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## jbrehm (May 16, 2006)

I've had a hydraulic tensioner go bad, but I caught it when it was just loose and before complete failure. I had a friend's go bad on her A4 - I had to put a new head on her car :thumbdown: 

I switched to a manual tensioner with the IE spacer, but I also cut down a failed hydraulic tensioner, and use it to keep a complete shield around the t-belt. Maybe I should put my build thread up here, where all this stuff is documented


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## Doooglasss (Aug 28, 2009)

jbrehm said:


> I've had a hydraulic tensioner go bad, but I caught it when it was just loose and before complete failure. I had a friend's go bad on her A4 - I had to put a new head on her car :thumbdown:
> 
> I switched to a manual tensioner with the IE spacer, but I also cut down a failed hydraulic tensioner, and use it to keep a complete shield around the t-belt. Maybe I should put my build thread up here, where all this stuff is documented


 
Nice! I like the idea- saves some money, uses OEM parts and protects the belt :thumbup:


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## Twopnt016v (Jul 5, 2009)

I have personally had a tensioner fail and I have seen two at the shop I work at in the last 4 years. The two that failed at the shop failed prior to when the belt would have needed to be changed. I've always owned/built a bunch of 16v cars so I really prefer the manual set-ups. You may need to re-adjust the belt once after the initial belt install but after that you shouldn't have to touch it, they are maintenance free. It may be the "cool kid" thing to do now but that came from the "real cool kids" making their own manual setups prior to any company manufacturing one. 

Good idea with using the old tensioner as a shield jbrehm.:thumbup:


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## sciroccohal (May 4, 2005)

*This i like!*

Wonderful you'se guys!...this is what I want. I'm a senior Mechanical engineer...for the LIFE of me I can't figure out WHY they designed such a fail-prone monkey-motion-linkage FAFF! 

Please post up your thread....I would be most appreciative. 

I'm sick of all the *FAIL HARD AND CATASTROPHIC STUFF* ON THIS CAR AND AM GOING TO REMOVE IT. 

I replace the timing belt every 30 k. 

thank you all.:wave:


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## sciroccohal (May 4, 2005)

*the next one.*

so help me god....I'm going to remove that *timing belt driven water pump* next....dumb, dumb, STUPID! (they should be ashamed!):screwy::facepalm:


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## Doooglasss (Aug 28, 2009)

Interesting... I've run the hydraulic tensioner on quite a number of cars. As long as you do a TB job every 60k you're good. I'm just shy of 600 crank hp on a hydro setup with no issues.


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## 20v master (May 7, 2009)

DougLoBue said:


> Interesting... I've run the hydraulic tensioner on quite a number of cars. As long as you do a TB job every 60k you're good. I'm just shy of 600 crank hp on a hydro setup with no issues.


 Over 350K miles on 4 1.8T's over the last 10 years with three being basic bolt ons and one well over 500chp, and I've never had an issue with timing belts, water pumps, or hydraulic tensioners. Change the parts on time and you won't have an issue either.


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## jbrehm (May 16, 2006)

DougLoBue said:


> . . . As long as you do a TB job every 60k you're good . . .





20v master said:


> . . . Change the parts on time and you won't have an issue either.


 
Sorry guys, but this is complete BS.  Why did you ignore the negative data, i.e., all the people who have had them fail? The fact is that these things fail well before their rated life, and it's not extremely rare for them to. I have _personally_ seen it twice, and I know a few more (in real life, not just an internet story) that have gone. If you look at the tensioner from an Engineering perspective, it is ridiculous to have that design for a critical engine component. Take an old one apart, and check how many pieces, AKA failure points, are in there! 

BTW, both of the failed units that I have personally seen had less than 20,000KM on them.


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## jbrehm (May 16, 2006)

sciroccohal said:


> . . . I'm sick of all the *FAIL HARD AND CATASTROPHIC STUFF* ON THIS CAR AND AM GOING TO REMOVE IT . . .


 Haha, every time I do major work on my car, I end up re-Engineering one of the OEM systems. The sad part is, I don't even have to do any real Engineering - so many of the stock parts are so crappy that I can just use common sense to replace it with a much better solution. :facepalm:


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## 20v master (May 7, 2009)

jbrehm said:


> Sorry guys, but this is complete BS.  Why did you ignore the negative data, i.e., all the people who have had them fail?





20v master said:


> Over 350K miles on 4 1.8T's over the last 10 years with three being basic bolt ons and one well over 500chp, and I've never had an issue with timing belts, water pumps, or hydraulic tensioners.


 I'm not ignoring negative data, I'm going off experience. Why do you ignore the negative data of people's manual tensioner setups shearing off the studs and doing the same damage as a failed hydraulic tensioner? If you accept the 105K mile recommended life, then yes, you'll have failures. If you go with a more reasonable 60K mile interval like Doug and any of us with real experience, you'll be fine. Yes, lot of people have broken the belt/tensioner and bent valves. How many of those people followed the 105K mile interval, or changed only the belt and not the tensioner, or the belt and tensioner but not the plastic impeller water pump? Probably most of them, ie they were cheap and it bit them in the ass. I stand by my previous statement. Change the parts on time, and you won't have a problem.


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## Doooglasss (Aug 28, 2009)

I had a shop forget to put the spacer back on my manual tensioner setup. Shredded my belt against the valve cover until it wrapped around the cam sprocket causing the motor just to seize luckily. I put a hydro tensioner back in after that.

Although that was human error- I could imagine the manual unit can come loose- especially with the spacer in there and unconventional longer stud that could be mis-sized or not strong enough.


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## sciroccohal (May 4, 2005)

*been there forever.*

'Why do you ignore the negative data of people's manual tensioner setups shearing off the studs and doing the same damage as a failed hydraulic tensioner?' 


You guys should know that I've been driving Mk1,2,3,4 VW and Audis my whole life, since I was 22. I'm 57 now. I'm no mechanical noobie. 

I have run both the GTI CLUB and The Scirocco Club for decades. 
I have never 'stroked a check' for ANY mechanical work in 107 VW/Audis. 
I ran my own VW shop for nigh-on 20 years. 

*The mechanical tensioners are as close to bulletproof as a human engineer can design.* 
I have seen the bearings in the pulleys fail, mainly due to over-tensioning or extremely high miles. 

*I have never seen or heard of the stud failing....ever! * for something like that to fail there are only two failure modes. 1. abuse 2. a manufacturing defect or a chinese/indian part was substituted. 

While I do indeed love the TT, there are a few things in the car that are absolutely SPECIOUS! 

The tensioner has 7500 miles on it, and at ZERO miles, wasn't doing it's job. 
There are tens of thousands of TT/GTI/ GLI etc owners out there that have the covers on the Timing belt assembly...they cannot possibly know that the tensioner is a piece of engineering crap....they've never seen it, felt it, replaced it by themselves. 

UNTIL IT"S TOO LATE. 

Please don't get me wrong, I asked for opinions, the foment and back and forth is Excellent. 
This all flows to our database of knowledge. 

Ps I'm so freakin' old I used to own an RO80! 1969! Great body...horrible engine!


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## jbrehm (May 16, 2006)

20v master said:


> I'm not ignoring negative data, I'm going off experience. Why do you ignore the negative data of people's manual tensioner setups shearing off the studs and doing the same damage as a failed hydraulic tensioner? If you accept the 105K mile recommended life, then yes, you'll have failures. If you go with a more reasonable 60K mile interval like Doug and any of us with real experience, you'll be fine. Yes, lot of people have broken the belt/tensioner and bent valves. How many of those people followed the 105K mile interval, or changed only the belt and not the tensioner, or the belt and tensioner but not the plastic impeller water pump? Probably most of them, ie they were cheap and it bit them in the ass. I stand by my previous statement. Change the parts on time, and you won't have a problem.


 I don't know how else to put it: your conclusion is illogical. There have been many failures before 60K miles; and, as I said, all of the failures that I have personally seen were _long_ before any reasonable maintenance interval. All it takes is one failure to disprove your guys' statements like "Change the parts on time and you won't have an issue either", and "you won't have a problem". All of the anecdotal evidence in the World won't disprove my statements. 

And I didn't ignore anything - I've never heard of a stud failure, and if they do fail, it's just a fastener, so you can upgrade it (like I did). And I think you know enough to know that most fastener failures are from improper install. 

Like sciroccohal, all of the guys that I know that have worked at, or owned, a VW shop for any length of time know that the hydraulic tensioners do fail.


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## 20v master (May 7, 2009)

No one said they don't fail. :banghead: You do whatever you want, I don't care what you do. That said, in all my experience, which is extensive, I've never had a problem with a hydraulic tensioner, I change them at 60K miles, and those are facts. The point was made earlier that most people don't know what a bad design the hydro tensioner is. Do you think those same people are going to check the tension every 5K miles? :banghead: Do whatever is best for you, but belts stretch, and this belt affects bearings in your water pump as well. Too tight and you'll burn that up too. Different strokes for different folks, but until I see a hydro tensioner on one of my cars fail before 60K, I'll stick with what has worked for me. There's no performance benefit to the manual tensioner, so a hydro is one less thing to have to check on (for me).


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## jbrehm (May 16, 2006)

Wait, are you guys claiming that all of the failures that have happened are only because the parts were older than 60k miles? How could you possibly know that? Everyone who tells you that the parts were not that old is lying? 

Doug, I don't see the point of posting - what you know is - a shop ****-up. Put in the spacer, use a stud that is appropriate, torque it correctly, and there's really nothing to fail (other than the bearing, but you can't get around having rollers/bearings in the system). I also roughed up the mating surfaces on the tensioner, spacer, and head to increase the coefficient of friction. I don't think it was necessary at the clamping loads we're talking about here (~8000lb, IIRC), but why not improve the system for 60 seconds of time.


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## jbrehm (May 16, 2006)

20v master said:


> No one said they don't fail . . .


 
Ummmmm, what? :screwy: 




20v master said:


> . . . Change the parts on time and you won't have an issue either.





DougLoBue said:


> . . . As long as you do a TB job every 60k you're good. . .


 
I'm not sure why, but it seems like you're taking offence to what I'm saying. I definitely don't mean it that way - I'm just analyzing the data as it is, and trying not to put my own personal bias on it.


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## Doooglasss (Aug 28, 2009)

jbrehm said:


> I'm not sure why, but it seems like you're taking offence to what I'm saying. I definitely don't mean it that way - I'm just analyzing the data as it is, and trying not to put my own personal bias on it.


 No offense taken. I was just sharing my experience of what happens when it's installed incorrectly. I have never seen a hydro tensioner fail- rather I've always seen the water pump seize up or find the plastic impeller exploded. I've fixed a handful of mk4's with this issue around 100k or so.

I've had success with hydro tensioners. I also have the head off my motor every 10k or so and replace it since it's cheap insurance to me (such as it is right now).

I'm just trying to share my knowledge learned with the rest of the thread like everyone else is. I hope nobody is taking the defensive/offensive here.


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## 20v master (May 7, 2009)

jbrehm said:


> Ummmmm, what? :screwy:
> 
> 
> 
> I'm not sure why, but it seems like you're taking offence to what I'm saying. I definitely don't mean it that way - I'm just analyzing the data as it is, and trying not to put my own personal bias on it.


 Saying that they'll last 60K miles isn't the same as saying they don't fail, I'm not sure how you came to that conclusion. My conclusion is not illogical as it is based on much more than casual experience with multiple vehicles driven for extensive mileage in varied conditions, and based on more than reading forum complaints/rants. However, you say you are analyzing data. What data? What sample size of 1.8T owners did you poll to come up with this data? Original owners? CPO cars? Owners do their own work? Owners even know what a timing belt is? :what: Like Doug said, no offense taken, and I'm also simply sharing my experiences. It's okay to disagree, this isn't a debate. :beer:


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## sciroccohal (May 4, 2005)

*just for the record*

Waterpump failure at 26k factory installed (plastic impeller, bearing) 
Timing belt failure at 26k factory installed see above 
dash cluster failure at 32k factory rebuilt and failed again. 3rd one in 42k miles. 
Tensioner failure at 7500 miles new belt, waterpump, thermostat, pulley... Genuine AUDI parts installed as per Bentley. 

My car is called TIGOLBITTIE my silicone boobed high maintenance tourist trophy wife! LOL 

Be nice guys! knowing all of you are contributing mightily! 

I do certainly appreciate it. *I listen to everybody, and discount nothing.* Great big hopper!:thumbup:


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## lite1979 (Sep 9, 2005)

Nice post, scirrocohal! My car's a trophy wife as well. Good thing I'm a butt-man, since her front end's all f***ed up. 

I haven't had any hydraulic tensioners fail on me, either, but then again, I've only had my TT for a little over 30k miles, and I replaced the timing belt/tensioner/water pump 5k miles ago. The pump that was in there was a metal impeller pump, but I was having all sorts of cooling issues two years ago, so it was probably all the tap water I put through her that ruined the water pump bearing... 
I've only done timing belts on two other 1.8t motors other than my own, neither of which ever had any issues with the hydraulic tensioner. 
Since I fell in love with VWs after owning my '89 Jetta, I agree that the manual design is a good one. I can only guess that it's easier install a new hydraulic tensioner than a manual one, since it's preloaded, and all you have to do is pull a pin to put tension on the belt. Of course I'm thinking of dealerships doing the job when I say this. I know it's not harder for anyone of us to put tension on a manual tensioner, but we're actually willing to get our hands dirty working on our own cars. Not all VW/Audi owners are like us. 

I feel like the first call to service in the Timing Belt area tends to be a plastic impeller water pump causing overheating, and most people replace the timing belt, tensioner, idler pulley and water pump when that happens. The mileage-related maintenance doesn't give you three beeps and cool graphic of a thermometer in water like overheating in our cars does, so it seems natural that we'd be more likely to ignore that kind of stuff.


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## Twopnt016v (Jul 5, 2009)

I checked records today at the shop and the two failures I have seen both happened under 40k with a factory tensioner. I agree to each is own. What baffles me is people throw all these expensive parts on their cars and don't skimp when it comes to anything but then they will run a failure prone tensioner...this makes no sense to me. I understand that if you personally haven't seen a failure then its easier to ignore the warnings. I would like to state for the record that these failures have happened to people with quality parts before 60k. You also don't have to check the belt every 5k or adjust it frequently if you have a manual tensioner. I have cars with manual tensioners that have been on for 10yrs and never needed to be adjusted. Just to stir the pot a little...One of my good friends that is always broke has ran the same hyd tensioner for 2 timing belt changes(150k) up until recently he had a leaking WP and moved to a manual set-up. This is just my .02...I understand where everyone is coming from but the failures do happen...:beer:


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## 20v master (May 7, 2009)

The other factor here, and it's the same with the belts, is it's not just mileage, it's age AND mileage. 2000 1.8T with 40K miles probably has had the tensioner fail. :laugh: I'm not saying all failures are from age, nor am I saying they don't fail. You hear more about failures than you do long lasting tensioners that outlive their intended use because that's what people do: complain. 



Twopnt016v said:


> One of my good friends that is always broke has ran the same hyd tensioner for 2 timing belt changes(150k)


 Do you think this guy has posted online and bragged out it?


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## Twopnt016v (Jul 5, 2009)

20v master said:


> The other factor here, and it's the same with the belts, is it's not just mileage, it's age AND mileage. 2000 1.8T with 40K miles probably has had the tensioner fail. :laugh: I'm not saying all failures are from age, nor am I saying they don't fail. You hear more about failures than you do long lasting tensioners that outlive their intended use because that's what people do: complain.
> 
> 
> 
> Do you think this guy has posted online and bragged out it?


 HAHA...true..He should:thumbup:...I had to refuse to do his T-belt unless he got a new tenisoner. I told him I don't care if its hydraulic or manual but its gotta be new. He fought it and wanted to see if the tensioner could see +200k. He had to fold to get some free work. Either way I get screwed doing a free timing belt job or a free head swap:laugh::beer:


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## Chickenman35 (Jul 28, 2006)

I've seen how the Japanese manufacturers ( Honda, Nissan and Toyota etc ) design belt tensioners. ( Worked at Nissan and Honda dealerships for 17+ years ) Nissan back in the mid 1980's was using gas pressurized tensioners and they incorporated a very simple fail-safe in their design. A one way ratcheting pawl. So even if the tensioner lost all gas pressure the tensioner could not back off. A very simple and elegant solution. 

BTW... our tensioners are not hydraulic, they are high pressure gas filled...which I'm sure everyone actually knows. Proper hydraulic tensioners are pressurized with oil from an oil gallery. Unfortunately this is normally only done with Timing chains because you always have some oil spray or seepage ( you need a vent hole )...but the things never *EVER* fail. At least not on Nissan's and Toyota's. 

Nissan went as far as putting a high pressure spring inside of the piston as a backup. On the original L-13 engine that predated the famous L-16, they even backed that up with a one way pawl !! Eventually they decided that having both the spring and pawl as a backup was a tiny bit of overkill. 

* Foot Note #1: Ford's 2014 ECO-Boost 1.0 L 3 cyl Turbocharged engine incorporates an oil immersed timing belt. This should enable them to use an actual oil pressurized tensioner. Interesting.... 

http://corporate.ford.com/news-cent...il/pr-ford-10liter-ecoboost-engine-sets-37426


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## sciroccohal (May 4, 2005)

*wp/belts/hp etc*

*so it was probably all the tap water I put through her that ruined the water pump bearing...* 

Nope...absolutely not! 

I'm a mechanical engineer by day! TT whisperer by night. 

Look at the lever moment on that loooong WP shaft, then stir in a seal that cannot tolerate any shaft deflection, then fold in a tensioned rubber belt pressing at some considerable force on the END of that lever.....recipe for disaster! I swear to god if FRITZ the engineer who designed this, walked into my office and said, You're the senior engineer, approve this....he'd be sweeping floors! 
This IMHO, is the biggest defect in the 1.8T. 

Of course, THEN they made the impeller out of plastic! Seriously, I have pictures of this shaft at a 10° angle to the housing, the bearing DOES NOT LIKE using antifreeze as a lubricant....trust me...for normal 70 mph driving to blown up sir!= 45 SECONDS! 

For our friend who is running 500 hp in his engine...unfortunately this is i*mmaterial *to the timing belt/tensioner issue. The belt sees no more horsepower transmitted than a regular 180 hp version. The tension/ shear force on the belt teeth is determined by 1. frictional drag in the valve train, which really doesn't change with HP. 2. Rotating mass 3. ability to gain rpm quickly...in that order.


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## Chickenman35 (Jul 28, 2006)

Actually Honda ( and other manufacturers ) have been using an internal WP driven by the TB for years on many different engines. Difference was, they built it properly and had no issues. Internal water pumps driven by the TB seem to be a pretty common design these days. Some manufacturers just build them better..... 

Edit: Having said that...I'm glad I have an AEB with an EXTERNAL W/Pump. 223,000 km on the original pump and still going strong. Mind you, an internal pump on a Honda, Nissan or Toyota would probably last as long. :beer:


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## 20v master (May 7, 2009)

sciroccohal said:


> For our friend who is running 500 hp in his engine...unfortunately this is i*mmaterial *to the timing belt/tensioner issue. The belt sees no more horsepower transmitted than a regular 180 hp version. The tension/ shear force on the belt teeth is determined by 1. frictional drag in the valve train, which really doesn't change with HP. 2. Rotating mass 3. ability to gain rpm quickly...in that order.


 So the belt/tensioner were designed for 8200 rpms and up? Is frictional drag the same at all rpms? A stroker crank and bigger pistons doesn't add mass? You don't think 500hp makes you "gain rpm quickly" compared to 180hp? I didn't know that. 

PS. You're not the only mechanical engineer with a TT.


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## Doooglasss (Aug 28, 2009)

sciroccohal said:


> For our friend who is running 500 hp in his engine...unfortunately this is i*mmaterial *to the timing belt/tensioner issue. The belt sees no more horsepower transmitted than a regular 180 hp version. The tension/ shear force on the belt teeth is determined by 1. frictional drag in the valve train, which really doesn't change with HP. 2. Rotating mass 3. ability to gain rpm quickly...in that order.


 Have you driven a BT car before?

While the power level might not make a difference but how I make it does I think. Power delivery of a ball bearing big turbo is later in the power band and very fast in onset. I'd have to imagine a 300 ft/lbs increase in torque in a short amount of time (about a second) adds stress to the belt and it's components.


Couldn't frictional drag be effected by aftermarket valves with different clearances, how the main/rod bearings & piston rings are clearanced ?


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## esoxlucios (Sep 17, 2009)

20v master said:


> If it was as loose as you describe, you'd be throwing a cam to crank correlation code. I've never had an issue with the hydraulic tensioner. Change it on time and forget about it. That said, all the cool kids have manual tensioners, but that's your choice.


Question: why would it being loose axiomatically cause the crank cam correlation fault? Because the belt had skipped a tooth?

Reason I ask is because I'm getting that fault intermittently over last few weeks, and my VVT was changed in May 2012, and the timing belt kit from DieselGeek (using all OEM parts, including tensioner) was replaced shortly before that with the engine build. From time to time, I've heard rattling that sounded like heat shield. I assumed it was from the downpipe work I recently had done, but after reading several threads on TB tensioner I'm worried. I don't hear it all the time.

Ross-tech mentions possible bad cam sensor or crank sensor, or clogged oil pick up (low oil pressure, thus VVT isn't charged).

I understand why a faulty VVT would set the code, but not why a faulty TB tensioner would, unless the belt had skipped a tooth.

How do you visually check the TB tensioner. Just check for play in the belt? How tight should it be?


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