Head Gaskets
#1
Head Gaskets
As some of you may know both the head gaskets have gone on my recently built forged engine (1100 miles). I have done a compression test and all 4 cylinders are at around 50 psi (one is 40).
Deck faces were done, heads skimmed, ARP head studs torqued in the correct sequence.
The opinion's I am getting is around the Head gasket's themselves being Cometic, and how they have a terrible reputation?.
Is there anything else that could have caused both to go at the same time? And at what risk are the ACL bearings now that water has got into the oil?
Deck faces were done, heads skimmed, ARP head studs torqued in the correct sequence.
The opinion's I am getting is around the Head gasket's themselves being Cometic, and how they have a terrible reputation?.
Is there anything else that could have caused both to go at the same time? And at what risk are the ACL bearings now that water has got into the oil?
#2
Scooby Regular
iTrader: (11)
Join Date: Sep 2010
Location: everywhere
Posts: 2,059
Likes: 0
Received 0 Likes
on
0 Posts
When api built my engine they advised me against the cometic gaskets. They told me to use standard subaru or cosworth as they were much better. So its possible the cometic ones are to blame.
As for bearings if youve caught it at early stages then i doubt the bearings will of been affected, normally the coolant burns off in the cylinder before it reaches the sump if its only a slight leak. Change the gaskets, fill with fresh oil and see how it goes.
As for bearings if youve caught it at early stages then i doubt the bearings will of been affected, normally the coolant burns off in the cylinder before it reaches the sump if its only a slight leak. Change the gaskets, fill with fresh oil and see how it goes.
#6
Scooby Regular
Join Date: Mar 2014
Location: Hillingdon
Posts: 996
Likes: 0
Received 0 Likes
on
0 Posts
If it never over heated u may of got away of doing more damage to the engine . But I don't need to tell u that . Don't start it just get it to a Subaru garage . ASAP . Hope all go's ok for u . Keep us up to date with wot happens .
Last edited by Jayjay100; 08 May 2014 at 09:21 PM. Reason: Spelling
Trending Topics
#10
I can confirm that the Cometics are a poor substitute for genuine Subaru or Cosworth gaskets & I won't use them again after one of mine went after 1000 miles. The faulty gasket was inspected by Paul Finch who did not do the original build, & it was confirmed as being faulty in that the bonding coating was substandard. The Cometic supplier argued there is no warranty on a head gasket & it wasn't worth a court case, however I still have the gasket as proof if ever I need it. However as already mentioned to loose compression on all cylinders is unlikely to be HG failure especially without overheating, I'd suspect a valve or timing issue. A cylinder leakage test will give you a better idea where exactly you've lost compression.
#12
Well when you think about it, it would only be 25% of valves that were wrong, and it would only need to be micrometers out, but again would be a long shot!
I agree about getting a leakdown test done.
Im not saying you have, but is there any way the gaskets could have been fitted upside down or similar? I have never done any on a scooby so I dont know if it is even possible, I know on my starlet and other engines I have built it is impossible to do as the studs dont line up.
I agree about getting a leakdown test done.
Im not saying you have, but is there any way the gaskets could have been fitted upside down or similar? I have never done any on a scooby so I dont know if it is even possible, I know on my starlet and other engines I have built it is impossible to do as the studs dont line up.
#13
Former Sponsor
Join Date: Aug 2012
Location: Holywell
Posts: 571
Likes: 0
Received 0 Likes
on
0 Posts
What makes you think its the headgaskets, did it get warm and push water out anywhere? The classic tell tale is that they pressurize the water system and push water out of the overflow or burst a hose/rad.
#14
There was water on the dipstick. The turbo had smoke coming from it after a mile of driving, so I pulled the turbo off and found nothing. Checked the cam belt timing and all was good. So ran it up until it was warm and checked compression which was 50 psi or thereabouts. That's when I checked the oil filler for blow by (not much) and the dipstick.
#18
Former Sponsor
Join Date: Aug 2012
Location: Holywell
Posts: 571
Likes: 0
Received 0 Likes
on
0 Posts
What sort of boost are you running? It's very rare to have an issue even with Cometic gaskets under 400bhp, ive run 9.0:1 cr on a semi closed deck block at 400bhp with Cometics. If it's not lost any oil and there is no obvious issues (knocking etc) I would get it up to running temp, allow it to cool for a while. Once you can take the header tank cap off SAFELY, start it up and hold it at fast idle (around 2000rpm) if the gaskets are leaking it will start to bubble and push the water out. Give me a call if you need to.
#20
Scooby Regular
iTrader: (1)
Join Date: Mar 2013
Location: Wilts
Posts: 1,123
Likes: 0
Received 0 Likes
on
0 Posts
Is it deffo water in the oil or could it be fuel?
As if its a new build and hasnt been ran in properly then you could be getting borewash.
What colour smoke did you see, and was it actually coming from the turbo or the exhaust?
Is it a new turbo?
Could be possible that the turbine housing has cracked and allowing water to pass back into the sump.
As if its a new build and hasnt been ran in properly then you could be getting borewash.
What colour smoke did you see, and was it actually coming from the turbo or the exhaust?
Is it a new turbo?
Could be possible that the turbine housing has cracked and allowing water to pass back into the sump.
#22
Scooby Regular
iTrader: (7)
Sorry mate but your just going around in circles chasing your tail trying to save money but in danger of costing yourself a new engine. I'm just saying it how I see it and trying to be the voice of reason, a few hundred quid spent in the right place will save you a few thousand.
I don't care what you do as it's not my money, just some friendly advice as you seem to be struggling at every turn and putting up a new problem thread every other week.
I think you need professional help and a fresh set of eyes on the job, but hey not my car, not my money, not my problem.
I don't care what you do as it's not my money, just some friendly advice as you seem to be struggling at every turn and putting up a new problem thread every other week.
I think you need professional help and a fresh set of eyes on the job, but hey not my car, not my money, not my problem.
Thread
Thread Starter
Forum
Replies
Last Post