# Advice on Motor--Next Steps



## EnduringCactus (Dec 20, 2009)

Hi,
My 2000 VR6 Passat has 240,000 miles. The transmission makes a clunk/slip when I step on the gas at lower speeds (so I accelerate with a light touch), and I get a blinking 'check engine light.' The code I get is 'right vacuum pressure' but that's not the problem. I assume it's a fluid issue in the transmission. 

The motor is sometimes a little rough on idle. I replaced timing belt, water pump and thermostat 40K miles ago. I figure spark plug replacement is a good start for the rough/cold idle.

All in all the car is getting a little tired. But it is still doing well and I am in the middle of a cross country road trip.

So I have a few questions that maybe some of you would be able to answer:
1. At what point should I re-build/replace the motor
- Is a rebuild worthwhile?
2. I figure I could replace the transmission fluid to see if that is causing the clunk.
- If that does not solve clunk problem is it worthwhile to repair/replace transmission

I do all the work on the car myself and would not have an issue with either of the above.

I never had a car last this long and I really want to keep it going. Just want to stretch as much as possible. Is 400K miles possible on these cars?

Thanks for your input.


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## skin piston (Dec 19, 2011)

*Hmmm.*

Interesting set of questions as my 00 Passat wagon has less than half the miles you mention, its engine sitting in an old tractor tire in the middle of my garage floor awaiting a resurface on its flywheel. I would venture a guess the clunk you are hearing to be excessive backlash in the ring and pinion gears. You should detect the clunk when loading and unloading the gears at low speed. At higher speeds the lash still exists but is less noticeable. Rough idle on start up might be a dirty or malfunctioning cold start injector. You are in the middle of a road trip, seems an ideal time to run a can of sea foam injector cleaner through. After all, what could it hurt? You have a pretty high mileage automobile there, the cost of parts for these things are almost blinding (I got a $920. quote for a new flywheel today) so depending on the condition of the vehicle you first have to ask yourself what it is worth to you to rebuild. The effort to get these motors out is great but like you, I enjoy the challenge. The best way to tell weather and more importantly where your engine is tired is to have a shop do a leak down test. They pressurize each cylinder with shop air and listen to different areas in the motor to find out where the blow-by is. Can save a lot of dough if you only need the heads re worked as opposed to the lower end too. I had my heads rebuilt on an old car I had and the engine at 140k pulled like it had a new lease on life. All depends where the problem lies. As to longevity, not sure what to tell you there. You are already where I figured my car would bee in oh say, 10 years. Good luck to you.


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## O_o (Nov 12, 2009)

EnduringCactus said:


> The motor is sometimes a little rough on idle. I replaced timing belt, water pump and thermostat 40K miles ago. I figure spark plug replacement is a good start for the rough/cold idle.


You could do that, or you could fix the vacuum leak.

I wouldn't bother with a rebuild on this engine, unless I were going to add some serious HP to it. Used engines with low mileage are easy to find, and relatively inexpensive. But that's just me.

If it's 4-mo, the clunk might just be the rear diff mounts. Is it a slushbox or man-tran?


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## EnduringCactus (Dec 20, 2009)

*Thanks*

Thanks for the response. Can you please describe the sea foam injector thing? I will try it.

I just did another 200 miles up to LA and back and it runs fine, so the motor seems to be doing well. The clunking issue is the most concerning.

My goal, don't laugh, is to get this car well over 300K miles. I could buy another car, but this is paid-for and it's been a truly outstanding automobile. The more I learn working on it the more money I save in the long run.

Thanks again for the advice, I really appreciate it.


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## EnduringCactus (Dec 20, 2009)

*Thanks*

Thanks for the reply. It's a regular 2WD with auto transmission. I really would think the clunk is a result of transmission issues. But not having had experience there, it's hard to know.

I don't see any loose vacuum hoses so don't really know how to fix the potential leak. Any advice.

By the way, I try to avoid dealers like the plague. Very expensive and often the work is no better than what I do myself.

Thanks again.


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## O_o (Nov 12, 2009)

First, I would get another scan and take note of the code(s). That might point you in the direction of where the vacuum leak is. It's not necessarily a hose that's loose or that's come off -- it could just be cracked, or it could be one of the EGR or PCV valves or hoses, or SAI if you have it. It could be basically anything between the MAF sensor and intake runners. And if you find one leak, there are probably more.

One shadetree way to find a leak is to get a can of ether or carb cleaner and, with the engine idling, spray little puffs around the hoses/intake. If the idle speed increases, then you're getting closer. If you have an air compressor and regulator though, seal up the intake, pressurize it to 2-3 psi (no more), and spray soapy water all over.

As for the clunk -- well first of all, I don't know much about slushboxes. However, does it only do it when it's changing gears? If so, is it only when between two particular gears, or going into a particular gear? And if not, is it only when it's in one particular gear? I would suggest playing around shifting manually to see if you can pinpoint the exact conditions of the clunk.


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## EnduringCactus (Dec 20, 2009)

*Thanks*

Thanks for the tips and insight. The last time I ran the codes there was a right bank vacuum code, which was new. It was one of many codes. The oxygen sensor codes have been on for the past 180K miles because I have never figured out how to replace it and will not pay the dealer 600 to do it. Figured I could reach it when I replace/rebuild the motor.

I need to drive 800 miles to another location. Then I will have a week to mess around with the car.

Will re-post learnings when it's fixed, or broken.

One thing is certain, this is the most reliable car I ever owned. It's been to Spain, Morocco, and everywhere in the US. And it's always been good to me when I remember to be good to it.


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## O_o (Nov 12, 2009)

A vacuum leak will almost always throw an O2 sensor code as well. Basically, the MAF sensor tells the ECU how much fuel it should inject, and the O2 sensor gives feedback as to whether it was too much or too little, and so it makes some small adjustments. But the MAF sensor can't know if air is leaking into the intake downstream of it. In that case, the two sensors won't be able to agree with one another, and so it will throw a code that one or the other (or both) is malfunctioning.


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## EnduringCactus (Dec 20, 2009)

*Advice on Motor--Next Steps--Updated*

So I decided to take the car to the dealer for their $117 checkout (it costs $225 in Arkansas). For that price I find a professional assessment worthwhile.

The clunking noise is supposedly being caused by a worn out motor mount. They wanted $17 for the part and $300 for labor. Needless to say, I will change-out that part when I do the timing belt next month.

Per the suggestions to my original post, I used Sea Foam and another engine treatment in two tanks of gas. Engine stuttering/shuddering is now gone. So I assume it's a spark plug fouling or injector issue. Will change spark plugs next month as well.

Thanks for the advice. The Sea Foam really works.


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## tryin2vw (Dec 30, 2006)

I have 287k miles on my 99 2.8L V6 Passat and still going strong and just got back from a 1500 mile trip from Greensboro, NC to Southeastern MI and back, no issues. I will be doing the next timing belt change in a few weeks.

If the interior is fine and you keep up on the maintenance, I feel 300K is easily possible and 400k is not out of the question. I have a 5 speed manual.


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