# Idle/starting issues, check engine light on now



## rob454 (Sep 18, 2009)

Hi all,

Seem to be having an issue here. I am coming home from work yesterday and my check engine light came on. Before this happened I have been noticing my car has been starting differently as well. The RPMs would rise higher on a cold start. This is on a 2005.5 Jetta with 103k miles.

The codes I have are 

*18711 - Leak in Air Intake System * (first code that pops up after I clear)
16891 - Idle Control System RPM: Higher than Expected. 
16555 - Fuel Trim; Bank 1: System Too Lean 


Ever since the MIL came on the car will sometimes idle at about 1500rpm when I put the car in park and it will start and misfire for the first 20 seconds, then it levels out. Overall, it idles pretty bad now. I am thinking it might be the PCV breather valve and I understand that is a part of the valve cover. Has anyone experienced this issue?


TIA,

Robert


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## tay272 (Aug 22, 2007)

looks like u got a vacuum leak somewhere around the intake. thats prolly throwin off ur air|fuel ratios makin the car run too lean and causin ur idle issues. could be something else but vac leaks on any vw engine usually always cause a rough or awkward idle.


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## rob454 (Sep 18, 2009)

I sprayed air intake cleaner everywhere and couldn't find the leak. I had the engine cover off last night and I couldn't find any visible leaks, holes etc.


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## rob454 (Sep 18, 2009)

Well, I decided to purchase a new valve cover since I am at 103k and I bet the seals are starting to leak anyways. The dealer sells it for $203.04 list price and I was able to get it for $144 shipped on DBC :thumbup: . 

I have done a bit of research and it seems that the "air intake leak" is leaking from the PCV valve section. I do have a little bit of oil inside the intake hose right around where it bends to the throttle body. I have a hunch that the PCV valve is seizing and spewing oil into the air intake system.

If I were to remove the connection to the PCV valve and close both ends, how would the car behave?


Also does anyone have a diagram of the removal of the valve cover? I had no reason to buy a bentley manual up until this point.


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## edb4 (Mar 4, 2009)

This should help: http://img228.imageshack.us/img228/4679/coverdiagram.jpg


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## rob454 (Sep 18, 2009)

edb4 said:


> This should help: http://img228.imageshack.us/img228/4679/coverdiagram.jpg


Yes, this will definitely help. Thanks!!


BTW do you have a pic of the tightening sequence and removal?


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## anteramk5jetta (Sep 11, 2011)

watch also cause if the gasket on the oil cap is going bad or cap is loose, this will cause a vaccum leak


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## rob454 (Sep 18, 2009)

Thats the first thing I checked when I noticed the issue. I did pull the dip stick and heard a very loud wooshing noise come from the motor. It sounded a little too excessive like too much pressure buildup in the motor. It started idling at 3k rpms when I got home today. It was very difficult to stop the car in drive so I am not going to attempt to use the car until I fix it.


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## edb4 (Mar 4, 2009)

Sorry, I don't have the tightening sequence data. I would IMAGINE that it's similar to many other components where tightening sequence matters, outsides and opposites first. But don't quote me on that.


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## edb4 (Mar 4, 2009)

Btw, this sounds very similar to the issues that I'm having (except my problem caused a rich condition to develop, oddly enough). Don't forget to clean off your MAF sensor because if you have oil reaching the bend before the TB, there's a chance your MAF got some of that oil, too. Bad MAF reading could lead to 3k RPM idle in a pinch.


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## Geo (Nov 14, 2000)

rob454, I was searching around the other day and came across this. Pretty nice post.

http://forums.vwvortex.com/showthre...-Problems-P2279-and-P0507&highlight=diaphragm


Quoted straight from dixie600mhz
"After some troubleshooting tonight I managed to nail the problem to a ripped diaphram inside a psuedo PCV valve on the front of the valve cover. The part is called the pressure regulator valve for crankshaft housing ventilation. The down side is that I can't seem to buy it separate from buying a complete valve cover. A new valve cover is $136 plus shipping. Check out the rubber piece that's causing all the headaches.

engine bay
http://img199.imageshack.us/img199/2055/enginebayp.jpg

cover diagram
http://img228.imageshack.us/img228/4...verdiagram.jpg

parts
http://img203.imageshack.us/img203/5138/componentss.jpg

rip
http://img704.imageshack.us/img704/7213/ripb.jpg 
FYI, I could hear this thing leak and could feel air sucking in the little hole in the bottom of the outer cover of the valve. I had the classic air leak symptoms where I couldn't pull the oil cap off with the engine running. When I shut the motor off I could still hear it suck air in for about 5 seconds through the faulty diaphram."

This should be easy enough to check before you pull your old valve cover off to verify the part.


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## rob454 (Sep 18, 2009)

Geo said:


> rob454, I was searching around the other day and came across this. Pretty nice post.
> 
> http://forums.vwvortex.com/showthre...-Problems-P2279-and-P0507&highlight=diaphragm
> 
> ...




I just bolded the top part. I hear that noise when I shut off the car. It just makes a hiss for about 5 seconds then fades off. I took my mechanics stethoscope into that area with the engine cover on, I am pretty certain that this is the issue. Its getting worse to the point where I cannot drive it so I am betting on it being ripped like in the picture.



The part will be here saturday or monday. I will update this post once I diagnose/replace the purge valve.

Thanks, these are great responses! :beer::beer::beer::beer:


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## tay272 (Aug 22, 2007)

Looks like youve pinpointed the problem but as said above, deffinately give your MAF a check and make sure its clean and working properly. This is another HUGE cause of rough/bad idle on VW engines and can cause many other strange problems that you wouldnt even think of. Hopefully its the PCV like you said tho and it gets fixed.


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## thygreyt (Jun 7, 2009)

Buy a new cover... Billet that is!!!

Sent from my GT-P7510 using Tapatalk


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## rob454 (Sep 18, 2009)

Well, I took the VC off and removed the breather hose and found 2 issues right away. 




























103k miles and motor is looking impeccibly clean! I did lube up the coilpacks with some sil-glyde, they were a pain to remove after 20k miles! I am pretty sure the corrosion is from the older revision coilpacks.


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## rob454 (Sep 18, 2009)

That vacuum hose I have shown above lists for $102!!! Luckily the dealer was kind enough to give me the P/N so I found one for $19 on ebay. I was planning on replacing the secondary airpump hose as well since it is brittle and possibly leaking. I notice the hose hitting are of a 'male' connection type. If I were to just hose clamp a 'female' connection type of aftermarket hose, would that work as well? I just don't think that this corrugated plastic stuff is worth anything IMO.


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## rob454 (Sep 18, 2009)

I just wanted to report back and say thanks to everyone for the help :thumbup: 


It was what I was speculating, I replaced the breather hose and valve cover and everything is back to normal. Check engine light is off and idling/starting back to normal. Car seems a lot more peppy and smoother. Seems the more this car ages the plastic parts in the engine get extremely brittle. I was gluing lock tabs and ziptieing connectors like crazy since they were just snapping off with almost no effort at all.

Thanks again.


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## thygreyt (Jun 7, 2009)

i know that this is late, buy i made a thread about "FAQ: valve covers."

it shows the torque specs and sequence.


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