rough idle caused by air leak

19367 Views 10 Replies 8 Participants Last post by Smileybug, Nov 2, 2015

dixie600mhz

Discussion Starter · May 5, 2010

My wife's 2006 2.5L new beetle convertible started to idle erratic yesterday. The car would almost stall then idle up to 1500rpm then almost stall. It only happened when sitting still at idle. Drive-ability at speed and acceleration felt flat but it was still driving. On the first day there was no engine error code but this morning I managed to pull two.

The codes were
P2279- Intake air leak detected
P0507- Idle speed faster than normal

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/img228/4679/coverdiagram.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.

Hope this helps others that might suffer from this problem. The car is just over 3 years old with 62k miles. I can't believe this rubber part might end up costing $150???

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hamsman

· #2 · May 9, 2010

Can't give you any info on the parts, but just wanted to say that the way you posted it with great photos will surely help someone else down the road.

Good luck on finding just the part, if you do, please post.

Don, aka.....the hamsman

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dixie600mhz

Discussion Starter · #3 · May 15, 2010

Hi Don, so it really did end up in buying a whole new valve cover. The upside is that it only took 20 minutes to fit last night. The car is now idling like new. All fixed.

Sucks it cost $150 to repair a ripped rubber part. My vette is cheaper run! No more VW cars in my future based on this adventure! FWIW, our toyota has covered 100k miles in 5 years and has only needed oil changes and tires. Lexus and toyota from now on.

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amidaous

· #4 · Oct 29, 2013

Diaphram part

Actually found the part at NAPA for 40 bucks. came with the cap, diaphram and spring. Was excited to post on here about it, but decided to wait to be sure it worked....... However, after installing it, it is doing the same, like it isn't sealing properly. Looks like I will be going through the same thing and replacing the entire cover. Thanks for the pics.. great help.

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pencilneck

· #5 · Oct 30, 2013

I've had a fellow I was helping out with a massive intake leak on the 2.5. He also got some "repair kit" for the CCV but ended up having to replace the valve cover as well. Sucks, look like it should be an easy fix, but if they don't seal up good... fuel trim is going to be screwed. IMHO, I'd go with a used valve cover before trying to repair that valve.

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dgbau140

· #6 · Mar 7, 2014

2.5l 2006 New Beetle P0507 and P2279

Thank you, after watching Youtube and coming the conclusion it was the MAF sensor I bought that but still had check engine light. Then my friend suggested looking at forums I found the exact issue/problem here. I broke two tabs to get the cap off and sure enough the diaphram was torn, local Autozone had to order part and two day turn around. I used a rubber adhesive to glue the piece back together. Let set 1hour and replaced. Works fine. Oreillys and Autozone both sell the part. 917-064

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Joe90

· #7 · Nov 2, 2015

Erratic idling 1.4 BCA engine

I hope one of you good people can help me here. The engine on my daughters 2007 Beetle seized solid so I've replaced it with a good BCA engine from a Golf. My problem is the car starts fine but after a short time the idle becomes really erratic and the EPC light comes on. If I rev it right up it settles down, the light goes out and will tick over fine until I next rev it when it repeats itself.

I'm tearing my hair out with this one, I've looked for air leaks etc but can't find anything obvious. Can anybody help me out of my misery?

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billymade

· #8 · Nov 2, 2015

A common problem; is the PCV valves fail and this causes, a air leak (requiring a new pcv or a whole new valve cover). Have you scanned the car for trouble codes?

Here is a thread; about the PCV failure issues, that are common with the 2.5L engine:

http://newbeetle.org/forums/2-5-liter-gas/65633-re-2-5l-pcv-valve-failure-solutions-dorman.html

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Joe90

· #9 · Nov 2, 2015

billymade said:
A common problem; is the PCV valves fail and this causes, a air leak (requiring a new pcv or a whole new valve cover). Have you scanned the car for trouble codes?

Here is a thread; about the PCV failure issues, that are common with the 2.5L engine:

http://newbeetle.org/forums/2-5-liter-gas/65633-re-2-5l-pcv-valve-failure-solutions-dorman.html

Thanks for your help Billymade. I've not scanned it for faults yet as I've been looking at the obvious coils etc but I'll do that tomorrow. would it correct itself temporally as the car drives really well and the tick over issue comes and goes with regularity?

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billymade

· #10 · Nov 2, 2015

I do not have a 2.5L Volkswagen; I did replace the PCV with a Dorman repair kit, in a Jetta, the owner complained of high idle, the car dying intermittently, check engine light on and overall, just odd drivability problems.

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Smileybug

· #11 · Nov 2, 2015

billymade said:
I do not have a 2.5L Volkswagen; I did replace the PCV with a Dorman repair kit, in a Jetta, the owner complained of high idle, the car dying intermittently, check engine light on and overall, just odd drivability problems.

Looks like the new poster has a 1.4L.

I would start your own thread since its a different engine. We don't have it here in the States though.

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