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oil in plug hole...

Posted: Tue Mar 15, 2016 7:07 pm
by neil.hunter
Hi All,

I'm after a bit of advice, 2001 Gti and its been running a but rubbish recently. Had a fault code for the camshaft adjuster valve (17927) so a new one of those is on the way (are they pressure operated) and also a cracked coilpack so that was replaced also.

My main question is though, the plug hole nearest the cam sprockets was full of oil, none has been split and I'm reading about the gasket needing resealing with specialist sealant? Timing belt off etc etc.

Is it normal to be full of oil and how has it actually leaked into the plug hole? Also, the top of the piston seemed quite gunked up yet it's compression testing all OK at around 14-15 bar across all cylinders...

Not to mention that I appear to be having to top up the coolant once a week but a pressure test says it holding pressure all OK.. (Possible cap?)

Please, I don't need this to be head gasket... Lol

Any help appreciated...

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:16 pm
by alexperkins
Where was the oil. On top of the spark or in the spark plug hole?

You might have a coolant leak in the radiator or heater matrix potentially if the head gasket isn't the culprit

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:25 pm
by neil.hunter
Thanks for the reply Alex, it did appear that the oil was mainly in the plug hole (the one nearest the camshaft adjustment valve). What worried me is that the top of the piston did look a bit crappy but again I don't know if that could be unburnt fuel from the weak spark after I found out the coilpack was arcing.

Are the rad and matrix usual suspects? It is frustrating me to say the least..

I'm nearly at the point of either getting rid, or an engine change but I don't think that'll help me as I'll be wandering into the unknown again...

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:27 pm
by alexperkins
I wouldn't be too worried. Oil could've been spilled in there or something similar

A bit of oil on the threads too isn't uncommon.

You could chuck a bottle of radweld in to see if that stops your coolant disappearing. I've had good results with that in the past

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:33 pm
by neil.hunter
Theres the thing though, when I last put a set of plugs in, a year ago, I noticed oil in the same plug hole and cleaned it all out.

To be honest, there was quite a bit in the plug hole :-/

I'd always assumed that radweld was nasty stuff for engines and therefore avoided it like the plague..

I'm happy to try if it aint gonna do no damage?

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:36 pm
by alexperkins
If there's no loss of compression and you aren't losing oil it's a bit of an odd one. The head gasket might be seeping oil very lightly

It shouldn't do any damage providing you follow the instructions

Radweld Gold is a better formulation albeit I've never had any trouble with the normal radweld

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:41 pm
by 937carrera
alexperkins wrote:I wouldn't be too worried. Oil could've been spilled in there or something similar

A bit of oil on the threads too isn't uncommon.
Could the oil just be a little bit of seepage from middle of the the cam cover. Maybe just nip it down a little and then ignore ?

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:43 pm
by alexperkins
It could be. Not unusual for the bolts to loosen a little over time

How many miles has it done?

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:46 pm
by neil.hunter
937carrera wrote:
alexperkins wrote:I wouldn't be too worried. Oil could've been spilled in there or something similar

A bit of oil on the threads too isn't uncommon.
Could the oil just be a little bit of seepage from middle of the the cam cover. Maybe just nip it down a little and then ignore ?
I have to be honest, I am suspecting the cam cover myself but only from previous stories I've been reading about them leaking and how much of a pain they are to reseal (Cambelt off etc).

Would a nip down possibly sort it then, if indeed that is the culprit?

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:48 pm
by alexperkins
If it's a little loose a nip down might fix it

It's a Cambelt off job to remove the rocker cover as the camshafts have to be removed with it due to the fact they pass through it

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:50 pm
by neil.hunter
Cheers Gents,

I'll give it a nip down tomorrow and report back in a few days re the leakage.

Many Thanks again.

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 9:59 pm
by 937carrera
Try to follow the rules for tightening order and use a torque wrench if you have one. It might also be worthwhile slackening all the bolts off half a turn before re-torqueing.

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 10:13 pm
by neil.hunter
937carrera wrote:Try to follow the rules for tightening order and use a torque wrench if you have one. It might also be worthwhile slackening all the bolts off half a turn before re-torqueing.

I'll have a look and see if the tightening sequence is on auto data, although I suspect it isn't.

Don't suppose there's a link for them? I know it's normally 10nm.. shall we say 15nm for a nip up?

Re: oil in plug hole...

Posted: Tue Mar 15, 2016 10:20 pm
by 937carrera
10Nm + 1/4 turn is the specification.

Having just looked in ETKA there doesn't seem to be a particular tightening order, so start in the middle and move diagonally outwards