Mike B Posted May 17, 2008 Share Posted May 17, 2008 Once more my T4 gasket is starting to let gas past it... I get these suckers good and tight when i fit them, but I have had 2 fail now after trackdays, and they are a real PITA to refit as the turbo has to be dissasembled... Does anyone have any advice about fitment and gasket types... I have always used the ones with a pressed rim. Sealing compound? The next one I fit needs to be the last one I fit! Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 17, 2008 Share Posted May 17, 2008 (edited) Have you checked the mating surfaces for trueness? is it just turbo and manifold, or have you any spacers? in theory there shouldn't be to much pressure build up, as presumably its a fair sized turbo,(edit, just read your spec, going to be fitting one of these very soon, so interested in the outcome;)) i know my old Nissan used to be prone to killing turbo gaskets, but that was small and subject to a lot of pressure. Edited May 17, 2008 by Tricky-Ricky (see edit history) Quote Link to comment Share on other sites More sharing options...
JamieP Posted May 17, 2008 Share Posted May 17, 2008 Dont use a gasket, i had a few problems with this and spoke with leon at JPS and he advised me to get both surfaces machined and not to use a gasket, worked perfect:) Quote Link to comment Share on other sites More sharing options...
Wez Posted May 17, 2008 Share Posted May 17, 2008 Which gaskets are you using, is it the compression type with the ridge? Quote Link to comment Share on other sites More sharing options...
Steve Posted May 17, 2008 Share Posted May 17, 2008 Which gaskets are you using, is it the compression type with the ridge? Does it matter which way gasket goes, ridge against turbo or manifold? Quote Link to comment Share on other sites More sharing options...
Wez Posted May 17, 2008 Share Posted May 17, 2008 Does it matter which way gasket goes, ridge against turbo or manifold? I always do ridge up towards turbo. As already mentioned you should make sure the surfaces are both flat as well. Quote Link to comment Share on other sites More sharing options...
Mike B Posted May 17, 2008 Author Share Posted May 17, 2008 (edited) Have you checked the mating surfaces for trueness? . Nope... you think this is nescesary? is it just turbo and manifold, or have you any spacers? Just turbo and manifold with a small gasket inbetween. Dont use a gasket, i had a few problems with this and spoke with leon at JPS and he advised me to get both surfaces machined and not to use a gasket, worked perfect:) really? That means taking off the manifold, and getting both surfaces machined... ball ache!! is this the only way to cure? Which gaskets are you using, is it the compression type with the ridge? Yes bud; exactly that. They are fine until they go to a track day and get hot, after that one corner always leaks. Does it matter which way gasket goes, ridge against turbo or manifold? not sure... The gasket will take up any imprfections in the surfaces, but when the car has been on track it seems to disturb the seal causing blow by. Removing the gasket would do it, but i had hoped there were some uber gaskets that dont use the compression ridge that would be stable under higher sustained temps... Jamie.. do you use your suraces neat or do you use a sealent? Edited May 17, 2008 by Mike B (see edit history) Quote Link to comment Share on other sites More sharing options...
Steve Posted May 17, 2008 Share Posted May 17, 2008 I always do ridge up towards turbo. As already mentioned you should make sure the surfaces are both flat as well. Thanks Wez Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted May 17, 2008 Share Posted May 17, 2008 Dont use a gasket, i had a few problems with this and spoke with leon at JPS and he advised me to get both surfaces machined and not to use a gasket, worked perfect:) I do all my exhaust seals like this espically on 38mm wastegate flanges. Make sure the flanges are true and then i just apply a very thin layer of high temp exhaust sealant. Ryan Quote Link to comment Share on other sites More sharing options...
and1c Posted May 17, 2008 Share Posted May 17, 2008 really? That means taking off the manifold, and getting both surfaces machined... ball ache!! is this the only way to cure? Its the most probable reason you are seeing gasket failures TBO. If they are both machined flat, some sealant compound will be more than adequate to ensure a total seal. it is a PITA taking the bits off..but once its done, its done and you wont have to keep replacing the gasket. Quote Link to comment Share on other sites More sharing options...
Mike B Posted May 17, 2008 Author Share Posted May 17, 2008 (edited) I do all my exhaust seals like this espically on 38mm wastegate flanges. Make sure the flanges are true and then i just apply a very thin layer of high temp exhaust sealant. Ryan So it's manifold and turbine casing off..? and then who do I take them to be machined, any good mancine shop? Like you say, job done properly... You really notice loss of spool when there is a leak. Edited May 17, 2008 by Mike B (see edit history) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 17, 2008 Share Posted May 17, 2008 I have trued up manifolds with a decent file, but the housing can be a bit hard. Quote Link to comment Share on other sites More sharing options...
paul mac Posted May 18, 2008 Share Posted May 18, 2008 So it's manifold and turbine casing off..? and then who do I take them to be machined, any good mancine shop? Like you say, job done properly... You really notice loss of spool when there is a leak. i would start with the manifold mate, the welding process will allways leave the potential for some warpage whether its XS power or Boostlogic, it is very easy to see if the surface is out of true with a proper straight edge, if you dont feel confident find a decent machine shop as setting up the manifold in a miller/surface grinder can be a PITA which some back street machine shops just cant be bothered to do Quote Link to comment Share on other sites More sharing options...
Mike B Posted May 18, 2008 Author Share Posted May 18, 2008 Thanks for the advice guys. Not looking forward to this job... the turbo is a royal PITA to get off, but I'm reconing the manifold will be worse. Quote Link to comment Share on other sites More sharing options...
michel lane Posted May 19, 2008 Share Posted May 19, 2008 goto CAS engineering , opposite motorscope mike , they will do it for you . are you sure its not your nuts coming loose and blowing the seal ?? Quote Link to comment Share on other sites More sharing options...
Mike B Posted May 19, 2008 Author Share Posted May 19, 2008 goto CAS engineering , opposite motorscope mike , they will do it for you . are you sure its not your nuts coming loose and blowing the seal ?? Hi Bud, I may have loose nuts... but I tightened them up good a proper, as tight as I could get and this is the second seal I have blown. It failed on a different corner both times... Have you had any failures... and how much force do you use? Quote Link to comment Share on other sites More sharing options...
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