Another v8 head gasket question

anyone else had a failure of an elring head gasket?i rebuilt my engine about 20k ago.tophat block,skimmed heads ,arp studs,elring gaskets,the problem is an oil leak and coolant leak at the front of both cylinder heads between head and block,it's not bad,doesn't overheat or anything ,I just top the coolant up now and again,was thinking of switching to cometic gaskets,anyone used them before?ive read about the locating dowel maybe stopping the head from going down far enough,the heads have been skimmed twice,can't remember what was taken off them ,I would rather fix it before it gets worse,any recommendations on gaskets?

I've always used Elring as these or Reinz are supposed to be the best. However, I have a history of failed HG so read into that what you will, although mine appears to be a block problem. I had to drill out my holes for the dowels in the head last time as they didn't feel like they were seating fully after being skimmed. Did you used the assembly lube for the ARP's as this will affect the torque, also what did you torque the ARP's to out of interest?

Can't remember the torque figures,maybe 80 lbs/ft rings a bell .i spent ages on the internet reading about the torque spec what everyone was using on this setup and just did it the same,it was built around 4 years ago,18k miles,if arp lube came with the studs I would have used it or a little oil on threads and under the nuts but can't remember,it only seems to drip a bit of water out now and again ,it's coming from front of drivers side bank ,it doesn't look like it's coming from higher up on the inlet manifold or water pump,and with a little oil seepage from passenger side bank at the same area,makes me think head gasket,it doesn't overheat or run rough so it's not loosing compression,

Sounds very very similar to my issue. Did mine up to 95NM as suggested as the ARP spec is crazily high. Have you tried torqueing them up again to check they haven't loosened off. That's the next job on mine.

I haven't checked the torque on them yet will try that tonight when home from work

Have you tried doing a pressure test on the water system? That may narrow the problem down further for you. I had a suspected head gasket failure and after several false starts eventually traced the issue to a tiny crack in the head itself and although mine had only been skimmed once they had done a few hundred thousand miles so were quite tired, possible skimming yours twice has stressed them differently.

Also when you had the top hats fitted, how much was skimmed off the block as that with skimming the heads twice might mean you're running quite high compression thus causing higher stresses on your head gaskets.

Muddy Vicky said:

Have you tried doing a pressure test on the water system? That may narrow the problem down further for you. I had a suspected head gasket failure and after several false starts eventually traced the issue to a tiny crack in the head itself and although mine had only been skimmed once they had done a few hundred thousand miles so were quite tired, possible skimming yours twice has stressed them differently.

Also when you had the top hats fitted, how much was skimmed off the block as that with skimming the heads twice might mean you're running quite high compression thus causing higher stresses on your head gaskets.

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Good point. Mine is a top hat block so block faced off & i'm also running higher compression with 4.0l pistons. Skimmed heads on last HG change may have pushed it too far with compression. Would certainly check the torques though. Easier on a gems than thor I believe.

I guess the block would have been skimmed also,but don't think compression is an issue ,I'm not pressurising the coolant ,or leaking compression out ,I've not pressurised the coolant system yet ,I'll try checking the torque on the head studs first,I am also running 4.0l Pistons ,it drives perfect it's just the little water leak needs fixed before it gets worse

I checked some of the head bolt torque,the ones in the suspect areas anyway,and they are still 90nm which is the spec I think,so they don't seem to have slackened off,might try get a dye to add to the coolant and see under a uv light where it is coming from,I first thought of valley gasket but from where I can see further up the head face looks pretty dry,and if it were to leak there I reckon it would go in the way and mix with the oil,martynv8 did you have your inlet manifold skimmed also to keep all the ports lined up properly?i haven't done this but might consider it if it's all to come to pieces to replace the gaskets,was looking at cometic multilayer steel gaskets but they are £150 the pair compared to under £20 for the elrings,I read a few posts on other people building their 3.5s and even when priming the oil pump they got a leak from the area I have,and it was down to crappy gaskets,don't know if it would be worth putting a little high temp sealer around the water and oil ways when doing it again

Ok, at least the bolts haven't slacked off. When I had the heads skimmed they also skimmed the manifold face to compensate as the last time I did the heads it was a pig to line up & my failures were always blowing into the valley so I did suspect whether the inlet manifold was lifting the inside of the heads (the Britpart valley gasket I used once didn't help). Skimming the manifold would have been an option but then no use with other heads.
I always thought elrings were about the best but you live & learn....maybe thats where i've been going wrong. Mine isn't loosing coolant but i'm getting pressuring. On the plus side mine passed it's MOT today & the emissions were the lowest ive ever seen it.

The inlet ports face haven't been skimmed on my heads,so my ports will be a little high on the inlet manifold,maybe this is enough for a little coolant leak,but wouldn't have thought so,I'm pretty sure it's a britpart valley gasket on mine at the moment,there is still a oil leak from the other bank around the same area and wouldn't expect the oil to take that route if it were the valley gasket,still thinking it could be the dowels holding it up a fraction and letting it weep a bit,funny for it to show after 18k miles though,will just have to take it apart and find out,if it s the dowels I'll just use elring gaskets again ,but if can't see anything wrong might order the cometic gaskets,but that can wait till I've got the disco back on the road for transport