Gti6 Head Gasket Failing

[Sloppy 0]

So as i regret even bothing to put my 405 back on the road with a gti6 engine in it seems the haed gasket is 'just' starting to go i.e literally last 2 days as the tickover has got lumpy on idle (cylinder nearest the flywheel is missing) and a bit of white smoke + a tiny bit of mayo starting in oil filler cap.

 

So i will check this before taking head off, prob a pressure test...

 

however im quite certain it is gone so,.

 

which gasket do people use pug oem or other suppliers

 

did everyone replace the bolts (haynes says the can be reused of there not 'stretched' past a certain length.

 

any hints or tips other than the above!

 

cheers Joe

[welshpug 1,657]

I used an o.e gasket with the minimum removed from the head, then the rest from GSF, inc head bolts at £15.50.

 

I haven't checked but I think a GSF gasket is a decent one, if your head needs a fair amount removing I would certainly use a thicker gasket due to the valve to piston tolerances, I wasn't worried with my engine as I had sent the pistons to Martin, (CRF 450) who enlarged the cutouts.

[Mad Scientist 106]

OE headgasket, which is steel multilayer. Aftermarket gaskets are poor.

 

Don't reuse the bolts. They aren't dear and they are under huge torque. Not worth the risk.

[Miles 331 1 Cars]

Most Aftermarket MLS gasket's are fine, Victor Rinz are good and the last couple I used where mellor all with good results,

Bolts etc I tend to use Payen but they are all part of a huge group now anyway

I've had 25thou skimed off the heads with std timing and no issue's

[Sloppy 0]

Most Aftermarket MLS gasket's are fine, Victor Rinz are good and the last couple I used where mellor all with good results,

Bolts etc I tend to use Payen but they are all part of a huge group now anyway

I've had 25thou skimed off the heads with std timing and no issue's

 

Cheers for that, i will ring gsf tomoz as i still have my trade account with them and see what type of gasket they offer i.e MLS and manufactuer.

 

I did a comp test with engine semi warm result was

 

1 being cambelt end

 

1 98

2 100

3 100

4 about 85 so well down on rest....

 

that sound about right?

 

did make me laugh how little they have compared to diesels!

[welshpug 1,657]

I'm guessing you forgot to hold the throttle open? they should be much nearer double that on a healthy engine!

[Sloppy 0]

ha ha yea i did forget!

 

the gauge is quite variable, you kind of have to glance at it really quick as its not holding the presure corectly, there more of a guide!

 

Its fair to say from my poor testing method that no 4 was about 25% down on the rest though and when you remove the coil power to no.4 the idle hardly changes.

 

i might do a retest before i order the head set!

Edited November 14, 2010 by Sloppy

[Sloppy 0]

had another go but just on 2 cylinders, 3 and 4

 

engine was pretty much cold reading 190 and 185 so really not that much different between the 2 prob 10 psi at the most if that which is less than 5%...

 

was a fault valve which i sorted hence low pressures, did open throttle to but dint make much difference?

 

i might invest in a brand new gauge to get more accurate readings.

 

has seemed to happen going from the bosch mi16 management to the gti6, i might just run it a week and check them again...

Edited November 14, 2010 by Sloppy

[welshpug 1,657]

if there's any hint of a HG I would not run it any more, a friend limped his 306 rallye home after his hg went and the head was scrap afterwards due to a groove left in the head.

 

another with a rallye again had a bottom end go not a week after getting the headgasket changed, he's ignored the signs of a dying HG, I think oil surge killed the already tired bottom end though.

[pug_ham 244 3 Cars]

1 being cambelt end

Its a Pug so #1 is flywheel end.

 

No idea why the guage doesn't hold the pressure like its meant to, its only been used twice before but not by me first time so I can't say if it ever worked.

 

Graham.

[SurGie 54]

I'm guessing you forgot to hold the throttle open? they should be much nearer double that on a healthy engine!

 

 

Its funny how when i did a compression test on a twin cam turbo MR2 without the throttle open, (after doing two i realised i had not opened the throttle) yet the compression was the same when i did open the throttle ???

[Sloppy 0]

Its funny how when i did a compression test on a twin cam turbo MR2 without the throttle open, (after doing two i realised i had not opened the throttle) yet the compression was the same when i did open the throttle ???

 

it made very little differnce, open or closed.

 

With this issue arrising on the gti management when it was not there before i think i shall do a bit more testing before i take the head off.

 

battery went flat so i will charge it up and do a re-test cold, then propely hot again to see how they campare...

[Sloppy 0]

well more testing as it was not literally pissing with rain and freezing!

 

(1 being flywheel end!)

 

no.1 182

no.2 190

no.3 190

no.4 185

 

engine was stone cold, so good results really.

 

only 10 psi from best to worst too....

 

im still confused.

Edited November 17, 2010 by Sloppy

[pug_ham 244 3 Cars]

Its not simply a failing coil pack on that cylinder is it?

 

IMO you'll get a lot more than a "tiny bit of mayo" when they go but it also might only start to fail when its warmed up a little if you only have a tiny fracture.

 

It might be worth taking it somewhere for a coolant sniff check when its warmed a bit for an extra check.

 

Graham.

[Sloppy 0]

Its not simply a failing coil pack on that cylinder is it?

 

IMO you'll get a lot more than a "tiny bit of mayo" when they go but it also might only start to fail when its warmed up a little if you only have a tiny fracture.

 

It might be worth taking it somewhere for a coolant sniff check when its warmed a bit for an extra check.

 

Graham.

 

Well it does confuse me, as said it has only started doing this since going to gti6 management vs the s16 stuff,

 

i will try get a sniff test done and see what that comes up with, and also do a proper hot test on the pressures, take it on a good run.

 

I have swppped the injector, coil and plug from the cylinder around and its still the same, i was thinking bad wire from ecu to this coil? not sure it thats possible, could just be extremely early stages of head gasket.

[Sloppy 0]

Good news, after running it a while had no further simptoms,

 

pressures remained steady on comp test,

no bubbles in coolant,

no s*itty oil etc

 

i was literally about to take head off and look as i thought what else, then i noticed just on the inlet manifold on no.4 cylinder (the one that was missing a bit) there was a tiny section of gasket misssing,

 

it was a bit crap and with swapping the looms inlet came off a few times, a bit must have dropped off when i went from the s16-gti6 loom, hence why the problems started then.

 

filled with silicone (new gasket on order) and now its spot on, im so glad i dint take head off and i was very close indeed!

 

only spotted it as i could hear a bit of hissing and looked closer...

 

must have been messing up the inlet pressure and mixture making it under then over correct all the time silly thing!

 

So much happyer now!

 

only other problem was it ramdomly cut out after a hard run up a hill, thought it was out of petrol but the tank vent was blocked so it created a vacume, sorted now and its even better again,

 

touching loads of wood, really seem to be on the money now! YAY