Rear of Na-t Manifold leaking
#1
Rear of Na-t Manifold leaking
Hey guys, So i started out with a cheapy 150$ xs power manifold. After A while I could not get the 2 rear most cylinder primaries to seal up.
So i sprung for cx racings new 11 gauge unit and it fit great, bolted right in place but now after a month or so of driving back to the same problem.
the rear cylinder is leaking again and i'm at a loss, Gonna yank it off and check all the surfaces and put a new gasket but anyone have some insight as to what could be causing this time and time again?
So i sprung for cx racings new 11 gauge unit and it fit great, bolted right in place but now after a month or so of driving back to the same problem.
the rear cylinder is leaking again and i'm at a loss, Gonna yank it off and check all the surfaces and put a new gasket but anyone have some insight as to what could be causing this time and time again?
#2
Lexus Champion
iTrader: (10)
how bad is it leaking? like you can hear it or just slightly feel some exhaust pressure coming out.
when you take the manifold off you check the flange with a true straight edge diagonally across from like top left to bottom right. see if there are any gaps, you can use a light from the other side and if it shines through you can detect the warpage usually, and a certain amount is allowed but not much.
If the manifolds check out or both warped the same way, then I would check the flange surface on the head for straightness. If you have a issue with the head surface then that could be why the manifolds are warping and leaking.
also it could just be the gasket. what type of gasket? some say not to use the one in the kits but just use an OEM exhaust gasket. I used the one in the kits and no issues as far as I can tell but I haven't checked in a while.
Tighten the exhaust manifold on in several passes. do not tighten one side down first, that is obvious though I guess.
when you take the manifold off you check the flange with a true straight edge diagonally across from like top left to bottom right. see if there are any gaps, you can use a light from the other side and if it shines through you can detect the warpage usually, and a certain amount is allowed but not much.
If the manifolds check out or both warped the same way, then I would check the flange surface on the head for straightness. If you have a issue with the head surface then that could be why the manifolds are warping and leaking.
also it could just be the gasket. what type of gasket? some say not to use the one in the kits but just use an OEM exhaust gasket. I used the one in the kits and no issues as far as I can tell but I haven't checked in a while.
Tighten the exhaust manifold on in several passes. do not tighten one side down first, that is obvious though I guess.
#3
how bad is it leaking? like you can hear it or just slightly feel some exhaust pressure coming out.
when you take the manifold off you check the flange with a true straight edge diagonally across from like top left to bottom right. see if there are any gaps, you can use a light from the other side and if it shines through you can detect the warpage usually, and a certain amount is allowed but not much.
If the manifolds check out or both warped the same way, then I would check the flange surface on the head for straightness. If you have a issue with the head surface then that could be why the manifolds are warping and leaking.
also it could just be the gasket. what type of gasket? some say not to use the one in the kits but just use an OEM exhaust gasket. I used the one in the kits and no issues as far as I can tell but I haven't checked in a while.
Tighten the exhaust manifold on in several passes. do not tighten one side down first, that is obvious though I guess.
when you take the manifold off you check the flange with a true straight edge diagonally across from like top left to bottom right. see if there are any gaps, you can use a light from the other side and if it shines through you can detect the warpage usually, and a certain amount is allowed but not much.
If the manifolds check out or both warped the same way, then I would check the flange surface on the head for straightness. If you have a issue with the head surface then that could be why the manifolds are warping and leaking.
also it could just be the gasket. what type of gasket? some say not to use the one in the kits but just use an OEM exhaust gasket. I used the one in the kits and no issues as far as I can tell but I haven't checked in a while.
Tighten the exhaust manifold on in several passes. do not tighten one side down first, that is obvious though I guess.
I've been using the Fel pro gaskets which i've never had an issue with my maybe thats it??
Is it possible that my head is warped right there?? The old crappy manifold literally used to back the nuts off till the point of losing them. This one seems still tight/locktighted but can tell it's leaking cause of the "airyness" when boost and the lag.
#4
Lexus Champion
iTrader: (10)
I have heard its best to use the original type of metal gasket. the thicker ones that come in the kits are supossed to leak over time.. I have those on there I should prob check mine. Not sure what the felpro ones look like but maybe try the thicker ones if there is an issue it could help seal or you could try the oem ones which are like several layers of metal. Usually its the header that warps not the head but if it keeps happening maybe something else. downpipe has too little flex? maybe you need a flex section in there. I don't have one but haven't checked for leaks yet.
#7
It wasn't exactly a 150 dollar chinese one, it was cx racings new 500 dollar mani and it happens to be leaking right in back where the old one was soooooooooooooo i'm yanking it off again, ordering an oem gasket and checking all the surfaces with a straight edge.
That'll be like the 10th time I've replaced the gasket/manifold. Next is taking head off
That'll be like the 10th time I've replaced the gasket/manifold. Next is taking head off
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#10
Lexus Test Driver
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I've never had that issue.
I've always use the original stock metal gasket no matter how old they are I reuse them and never leaked!
I don't think the head is wrapped, the gasket got blown from the heat, and get some new exhaust manifold studs that will fix your studs issues, the new ones have lock tight on them already.
You don't need any bracing.
GL
I've always use the original stock metal gasket no matter how old they are I reuse them and never leaked!
I don't think the head is wrapped, the gasket got blown from the heat, and get some new exhaust manifold studs that will fix your studs issues, the new ones have lock tight on them already.
You don't need any bracing.
GL
#11
Well guys I installed the new 500$ cx racing thick manifold and an oem gasket with the new studs and a jam nut on each one.
Drove great for a while but again as soon as it spools you hear massive air. Gonna see if its leaking in the back like last time.
Car still pulls good but is super loud and a/f ratio is a little funny at times. Wastes a ton of gas compared to usual also.
hard to really differentiate when the wastegate is opening and when its just air leaking.
Drove great for a while but again as soon as it spools you hear massive air. Gonna see if its leaking in the back like last time.
Car still pulls good but is super loud and a/f ratio is a little funny at times. Wastes a ton of gas compared to usual also.
hard to really differentiate when the wastegate is opening and when its just air leaking.
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