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Audi A4 ALT 2002 - Crank case pressure #

Posted by Sam Green on September 29, 2011, 9:23 am

Year of Manufacture *: 02
Engine Size and Code *: alt

Hi all

Can anyone tell me if there is a way of messuring crank case pressure on the above mentioned vehicle. This one seems to be drawing a lot of oil into the intake and going through about 1.5 gallons on a long journey(400 miles). But does not seem to smoke out of the tail excessively

Thanks
Sam

Re: audi a4 crank case pressure

Posted by Simon Forsey <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5231' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 9:37 am, in reply to "audi a4 crank case pressure"

Hi

If you have it, a great way of testing is by using a Pico scope and a WPS500 pressure testerin the oil dip stick hole.

This kit will graphically see the actual running pressure.

I am not sure if there is another reliable way of checking, maybe on of the other techs on here will have more ideas.

Regards

Re: audi a4 crank case pressure

Posted by Sam green <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3007' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 12:30 pm, in reply to "audi a4 crank case pressure"
Sam Green

Thanks for quick response simon. I am waiting for the adaptor for my modis to come so havent got one yet. What sort of reading would you expect to see? If the engine is running on this one and you undo the oil filler cap, it's trying to suck the cap back on if lightly lifted. I haven't got another one to try this on to see if it's the same!

Re: audi a4 crank case pressure

Posted by Mark Carter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 1:07 pm, in reply to "Re: audi a4 crank case pressure"
Mark Carter

I think you will find that this is a common fault and you need to replace part of the PCV breather set up. HTH

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: audi a4 crank case pressure

Posted by sam green <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3007' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 1:43 pm, in reply to "Re: audi a4 crank case pressure"
Sam Green

I replaced the valve in the cam cover/breather last year so i know that is ok, seems like far to much vacuum, sucks the cap on and smoke down the dipstick tube.....untill you nip the pipe coming from the breather valve to the servo pipe/inlet

Re: audi a4 crank case pressure

Posted by Chris Angus <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5111' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 3:29 pm, in reply to "Re: audi a4 crank case pressure"

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I would double check that if I were you!
I agree with Mark, sounds like a faulty breather, if you can nip the pipe to fix the problem, then it has to be the valve.

Chris

Re: audi a4 crank case pressure

Posted by alan potter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2830' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 5:51 pm, in reply to "Re: audi a4 crank case pressure"
Alan Potter

I had a fault with the crank case vac on one that was hard to track down. The fault was down to a small non return valve in the hoses that are down the near side of the crank case there was a tee joint and one of the pipes was smaller and it turned out the reducer was a small valve, it is closed at idle and open under load, the faulty one sometimes did not seat properly this upset the fuel trim at idle, its not on every engine code though and was not on the audi parts list for the engine code i had. There was a pt no on it. Don't know about oil use but the vacuum was way to high at idle. but only sometimes!

Re: audi a4 crank case pressure

Posted by Sam green <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3007' width='330' height='300' border=0 style='border:none;'> on September 29, 2011, 9:13 pm, in reply to "Re: audi a4 crank case pressure"

Cheers guys. Alan.... I think that's the trouble I'm having. I think maybe there is a blocked pip into the inlet and compensating by sucking harder down this pipe and in turn sucking oil into the breather valve. Very tight down o/s. Can you guide me to these valves. Back on to this one when not so manic! Engine code is alt Thanks

Re: audi a4 crank case pressure

Posted by john fletcher <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5112' width='330' height='300' border=0 style='border:none;'> on October 12, 2011, 2:43 pm, in reply to "Re: audi a4 crank case pressure"
John Fletcher

Hi Sam
I agree with Alan when the engine is running if you take the oil filler cap off and there is alot of suction the breather valve under the manifold is not working or blocked I can,t remember which pipe it fits in but it was no big deal to change hth John

Re: audi a4 crank case pressure

Posted by Shaun Dale <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2719' width='330' height='300' border=0 style='border:none;'> on October 17, 2011, 3:15 pm, in reply to "Re: audi a4 crank case pressure"

Hi Sam,
Not sure of the engine code with this vehicle but I had crankcase vacuum problems last year caused by a faulty vacuum valve in the inlet pipework. It was located in the small(6-10mm) pipework under the inlet manifold, I think it was green in colour. The important bit was it had a circular blanking disc inside returned by a small spring, looking at it, it appeared that due to vibration the disc wears down on its outer diameter until finally it is too small to consistently block the orifice. Hence sometimes it's ok and sometimes not.
Shaun

Re: Audi A4 ALT 2002 - Crank case pressure #

Posted by Ed Kaps <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5536' width='330' height='300' border=0 style='border:none;'> on October 18, 2011, 12:24 pm, in reply to "Audi A4 ALT 2002 - Crank case pressure #"
Edward Kaps

Regarding Sam's original question.
We use a U tube with water to half way, one end into the dipstick tube, other to atmosphere, almost all engines will run with just a couple of inches of negative c/case pressure which you can measure off on the difference between water levels in the tube,.... Most of the time the water just gets sucked in...sure sign of a problem.
Alans reply will be your problem.
Ed Kaps

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