Vr6 oil leak , opinions please..

[VW_OwneR_85 2]

hi guys, noticed an oil leak the other day on my 24v 2.8 , so decided to have a butchers today , with next to no room to look I whipped the front end off along with inlet manifold and thermostat housing as it seems to be coming from the upper timing chain cover but there is oil dampness on the front right corner {right next to the timing chain cover/thermostat connection} of the head gasket which ties into the oil dampness of a possible weaping chain cover , is it physically possible for the head gasket to leak from this area ? or is it more then likely coming from the chain cover and running along the head gasket and then down the front of the block??, iv removed the chain cover and it wasn't sealed with any gasket or sealant so im hoping its that , thanks....

 

[vw rule 19]

Hello there,

 

yes it could be leaking from the top chain cover if you say the end part of the head gasket is missing,

the only way really to do it properly is to remove the cylinder head and replace the whole head gasket.

 

But I have done it before with out having to do that, but you have to make sure a few things are done right first though.

 

The small spill of oil you've got on the front edge of the lower chain cover close to the thermostat housing,

that could be where it's run down off the inside of the upper chain cover.

You've said you couldn't see any signs of a gasket on there, but were there any signs of sealant used or not ??

http://www.ebay.com/itm/MK4-VW-GTI-VR6-2-8L-24-valve-BDF-UPPER-TIMING-CHAIN-COVER-SEAL-FACTORY-OEM-/121166506283?pt=Motors_Car_Truck_Parts_Accessories&hash=item1c3616292b&vxp=mtr

 

It just might be where that cover / covers have been taken off in the past and resealed,

and the old sealant has just fallen out due to being really old ??

 

 

1) if the end part of the head gasket is missing already,

then make sure that it has been cut flush and evenly with the end of the head.

 

Because if it hasn't it can weaken it, if it's just been torn / ripped off.

I think there are 20 head bolts used on the VR6 head,

so if the head gasket has been ripped off unevenly it could course sealing problems,

as oil can weep from under the gasket close to one of the end bolt holes,

the two that are in line with the top chain cover.

http://www.thegasketshop.net/index.php/vw-corrado-golf-passat-sharan-vr6-2-8-2-9-head-gasket.html

 

2) Make sure all surface areas are clean and smooth / flat.

 

3) I would only use Loctite Blue, this type of sealant is very good for water and oil,

and has an amazing strong bond,

you can use silicone sealant but I find this isn't as good as Loctite Blue, as it takes longer to set.

LOCTITE BLUE SEALANT

http://www.ebay.co.uk/itm/LOCTITE-BLUE-SILICONE-GASKET-MAKER-AND-SEALANT-40ml-/370786693286?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item56549bf0a6

 

Just make sure you apply evenly to all sealing faces,

and if you've not got a new o-ring to attach in the thermostat housing,

then you can use the old one as long as it's not rock hard or splitting.

Simply fill the o-ring ridge up with sealant (BUT EVENLY) gently push in the o-ring,

and cover with sealant.

Plus try to apply the sealant slightly thicker on the outer facing edges,

so when you reattach the chain cover it should ooze sealant out more on the outside,

to complete the bond as you don't want it to ooze on the inside,

and drop down in to the sump.

If the sealant is too thick it will ooze out too much and could still leak,

and again if it's too thin it'll leak as well especially it there's no gasket.

 

4) Check the two sensor seals are both ok as oil can leak from them as well.

 

5) Make sure all bolt threads are ok and don't have a alloy on them,

as this will mean you've got weak threads in the cylinder head.

 

6) Check antifreeze strength, if it's weak then add more or replace.

Plus check all coolant hoses for any cracks and hardness,

any hose that is rock hard or feels crunchy when you squeeze it,

then replace them as this would be the best time to do so when the coolant is already out.

Same with the radiator and the heater matrix, just check for any signs of leaking.

Radiators normally go around the plastic tank area at the bottom,

and the heater matrix you'll have a strong smell in the car,

or water / antifreeze stains on the carpet.

 

7) Replace the top valve cover gasket even if it's fairly new,

as it's been compressed so could be weak.

I find the VW Main dealer gaskets are much better than the after market ones.

 

The chain covers don't normally crack, not unless the timing chain has been hitting against it,

due to a weak / broken chain guide / tensioner.

Or if they've got heat damage, in which case the cover will only leak once the engine is up to temp,

then the leak will show it's self.

You can check the cover for any cracks, but it's best to wash / clean it first.

 

8) You can tighten the chain cover bolts up with a 1/4" ratchet that way you shouldn't be able to over tighten them,

or on the safe side use a torque wrench.

 

9) Once everything is bolted up tight just have a look and make sure,

that you've got a even ooze of sealant all around the fitting in question,

because if not it could still leak.

 

10) You should really repalce the inlet manifold gasket for new as well,

but you can use some of the LOCTITE BLUE but apply it very thinly and evenly,

as you don't want any sealant bits in the inlet.

 

 

Hope this helps.

 

Si

[VW_OwneR_85 2]

cheers si, the head gasket is intact and nothing missing, iv searched through a ton of pictures of bare vr6 blocks and heads and on that corner there seems to be a coolant passage and not oil so its safe to say that its pretty much impossible {nothings impossible but you know what I mean} for the head gasket to leak oil like I was suspecting with mine, but yea im goning to order new seals for it and clean it all up and re seal :) , I was prepareing myself for timing chains + guides + new clutch but don't fix what aint broken is now my new motto ...

[vw rule 19]

Ok mate no worries, good to hear your head gasket is ok.

 

Your chain guides do wear over time,

the chain creates ridges in the nylon liners,

plus the nylon liners can break lose from the guide bracket,

as the nylon is only bonded or riveted on.

 

Plus the timing chains stretch over time,

which makes them slack even if the tensioner is doing it's job.

A well warn chain / chains will rattle.

 

The sprocket gears wear as well,

the ends of the teeth should be slightly tapered and flat,

but once warn badly they become pointed and so can slip out of the chain links,

or the chain can become very slack coursed by the warn sprockets.

 

Check condition of the chain tensioner as well,

some are oil fed so rely on the oil pressure to keep correct tension,

and others are spring loaded, which can be adjusted by hand i.e spanner / ratchet.

 

I would have a very close look of the above just in case one of them is warn,

it's better to do it now if it's needed.

 

 

Hope this helps.

 

Si :thumbleft:

[VW_OwneR_85 2]

yea I looked at the top 2 tensioner guides and theres hardly any wear into them surprisingly, im replaceing the hydraulic tensioner though as that seems rather rough to compress and has wear marks on its shaft {ohh errr}

[vw rule 19]

Cool, hope you get your oil leak sorted.

 

 

Si :thumbleft: