MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: dazza on March 07, 2015, 04:34:22 pm

Title: Valve Cover Leaking Oil
Post by: dazza on March 07, 2015, 04:34:22 pm
Since my DIY on the cam chain, tensioner and adjustor. I'm getting a trace of oil from the back corner of the valve cover near where the two pipes are connected. I've checked the torque on the bolts.

The leak seems to be right where a bot is. One bolt is also rusted??

I wasn't to bothered at first having never had to top up the oil before. But i've gone from max to half way on the dipstick recently.
Title: Re: Valve Cover Leaking Oil
Post by: th3_f15t on March 07, 2015, 10:18:12 pm
Possible gasket failure? If a bolt has corroded then chances are its taken any gaskets/seals with it.
Title: Re: Valve Cover Leaking Oil
Post by: dazza on March 07, 2015, 11:12:32 pm
The bolt was corroded when i changed the seal. I don't really feel like pulling it again. The two pipes at the back were a PITA. Unless i can leave them attached and just replace the seal?
Title: Re: Valve Cover Leaking Oil
Post by: th3_f15t on March 08, 2015, 09:45:25 am
Always worth a try, but sadly I don't think life will be on your side again for this job... :(
Title: Re: Valve Cover Leaking Oil
Post by: dazza on March 08, 2015, 09:53:03 am
So you think i should give the a good clean, replace a gasket and the corroded bolt?
Title: Re: Valve Cover Leaking Oil
Post by: th3_f15t on March 08, 2015, 02:32:58 pm
Yeah, and check the valve cover itself for any cracks. Could of been damaged when you refitted it? Wonder about maybe using VCDS or something to check oil pressure, and see if you can feel air leaks from around the area where there is oil?
Title: Re: Valve Cover Leaking Oil
Post by: dazza on March 08, 2015, 03:45:54 pm
The thing is there is no oil dripping down the back of the cover. But when i touch the join i get a trace of oil. I will get it done. I'm sure it will be easier than last time.
Title: Re: Valve Cover Leaking Oil
Post by: th3_f15t on March 08, 2015, 04:22:52 pm
The thing is there is no oil dripping down the back of the cover. But when i touch the join i get a trace of oil. I will get it done. I'm sure it will be easier than last time.

I would guess at some sort of hairline crack that allows oil under pressure to seep through then, but I'm no mechanic so it's only a guess.
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 08, 2015, 10:59:30 am
So the little oil leak has now reached the floor.

Pulled the valve cover. So that didn't seal very well.

Options?

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fimages%2F20150508_113855_resized.jpg&hash=6be866c360e6cb27add20fda3ac30d496123e9d2)
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 08, 2015, 01:51:30 pm
Cleaned everything up the new gasket is in.

Valve cover bolts tourqed to 10NM?

I could not get the jubilee clip i got from VW to fit. There is not enough space to slide it down the pipe then back over once its on. (see pic the large pipe at the back with the tissue in.)
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 08, 2015, 04:45:07 pm
All finished hopefully i've done a better job than last time.
Title: Re: Valve Cover Leaking Oil
Post by: th3_f15t on May 08, 2015, 07:45:49 pm
Keep an eye out and see if it reappears. Hopefully not.
Title: Re: Valve Cover Leaking Oil
Post by: doylebros on May 08, 2015, 08:09:34 pm
The last one I done of those covers required a few of the bolts replaced as it had a combined seal and the oil was passing the bolt not the cover gasket.
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 08, 2015, 08:16:12 pm
Thanks guys i replaced the 5 bolts at the back. And gave everything a good clean.

But the head felt rough in places.

Going to give the engine bay a good clean next week. Will probably try and clean the mess from underneath also.
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 09, 2015, 03:52:50 pm
The valve cover is still leaking from the back. Around the second and third bolt from the left not sure on the first bolt as i can't get at it.

These bolts are new. I don't get it. WTF am i doing wrong??
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 09, 2015, 04:19:35 pm
I used a mirror to check the gasket where the leak is. It seems to be sitting nicely.

Could a faulty PCV cause a leak??

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fimages%2F20150509_171345_resized.jpg&hash=3e44eaced5a360b1532d38b513a39229f06ea5dc)
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 10, 2015, 01:23:30 pm
Going to get a new PCV on monday. Although i seem to have the correct boost and a rough idle when i pull out the dipstick.

If this doesn't work maybe a new valve cover??

@vRSAlex (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=1981) any thoughts on this??
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 09:32:18 am
Just replaced the PCV the old one does not seem to be faulty.

The new one is version R do i need to replace the rear breather tube?
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 12:43:10 pm
By the looks of it i wasted my money on the PCV. Gasket is still leaking.

Before splashing out on a new valve cover going to try and replace the rear breather. As this vents pressure from the crank case??
Title: Re: Valve Cover Leaking Oil
Post by: olethalb on May 11, 2015, 12:57:55 pm
the rear breather is for both crank and cam cover ventilation 'off idle'

intake pipe via pcv is breather for both 'on idle'

there is no pressure in the rear pipe whatso ever unless (sure you mentioned having the earlier pipe) you hae the check valve pipe and it's faulty - in which case remove the check valve  :smiley:
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 01:07:11 pm
the rear breather is for both crank and cam cover ventilation 'off idle'

intake pipe via pcv is breather for both 'on idle'

there is no pressure in the rear pipe whatso ever unless (sure you mentioned having the earlier pipe) you hae the check valve pipe and it's faulty - in which case remove the check valve  :smiley:
So the earlier pipe will not have a check valve? The PCV i replaced was version L.
So rather than buy a new pipe i should remove the check valve in the rear breather if it has one?
Would this account for the leak?
Title: Re: Valve Cover Leaking Oil
Post by: olethalb on May 11, 2015, 01:13:31 pm
only way it would leak is if the rear pipe check valve failed and it's creating pressure off idle, i'd expect exhaust gas to smell a little oilier than usual too.

it's worth a check but sounds more gasket / mating surface related. was it an OEM gasket? and you fitted bolts through gasket before cover installation?

Title: Re: Valve Cover Leaking Oil
Post by: olethalb on May 11, 2015, 01:19:05 pm
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Follethalb%2Fparts_for_sale%2FB48E19AA-1DEA-49EB-A27F-AAD893DA1BC4_zpsptyq4gjs.jpg&hash=3a0d800ddccbc244061fac8f55fc02634a1df201)
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 01:25:40 pm
only way it would leak is if the rear pipe check valve failed and it's creating pressure off idle, i'd expect exhaust gas to smell a little oilier than usual too.

it's worth a check but sounds more gasket / mating surface related. was it an OEM gasket? and you fitted bolts through gasket before cover installation?
Yes it was an OEM gasket.
I did not fit the bolts through the gasket before cover installation. I did the first time and it failed.
Title: Re: Valve Cover Leaking Oil
Post by: olethalb on May 11, 2015, 02:59:53 pm
9 times out of 10 you can bolt the bolts in after but you risk nicking the gasket, the bolts are designed so the gasket holds them in place when removed, i always push the bolts through the cover / gasket first before fitting.
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 03:16:26 pm
I've removed the valve cover again. See pick below.

If the rear check valve is in the very end of the pipe i don't have one.

Don't know what to do now.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fimages%2F20150511_160202_resized.jpg&hash=19ed83c6a5838287dc27ecbcc963e3c62a6b4a3c)
Title: Re: Valve Cover Leaking Oil
Post by: olethalb on May 11, 2015, 03:22:04 pm
check gasket around bolt holes make sure you haven't nicked it anywhere (unlikely you have but worth a check)

stick your finger down rear pipe if it goes all the way you in you have no check valve

check mating surfaces are clean and smooth

also inspect cam cover for damage etc unlikely as that is

Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 11, 2015, 08:34:34 pm
I had another go. Its a bit better still leaking from the back on the right this time.

Debating getting a new valve cover or replacing all of the old bolts??
Title: Re: Valve Cover Leaking Oil
Post by: dazza on May 12, 2015, 11:56:52 am
Went to the stealers today they had a handful of bolts.
So the back and middle row of bolts have all been replaced with new bolts.

There is still a small leak from the very back right. Going to leave it a few days maybe it will stop.
Should i also replace the front row of bolts?
Title: Re: Valve Cover Leaking Oil
Post by: Scottymon on February 19, 2016, 07:11:38 pm
Did your leak ever completely stop @dazza (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10457)
Title: Re: Valve Cover Leaking Oil
Post by: dazza on February 19, 2016, 07:40:01 pm
Did your leak ever completely stop @dazza (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10457)
Yes mate when i replaced the bolts.