Head to mani gasket blown, second time! WHY????

Paul_JJ

Member +
It was professionally fitted and it's been around 4 weeks and less than 500 miles.... and it's blown now!!!


Tired of wasting the money on the gaskets!

I was given advise to put some hi temp silicone sealant on the gasket - it would help to seal it!

I have some SILI gasket left which is engine/cat friendly and will dissolve itself under extreme heat (used like oil sump seals) - so I think may be put that next time I have to replace the gasket???


Reps given as usual!

Paul
 

Dub-Se7en

Lifer
best guess, the mani is warped creating a weakspot in that area, remove it, have the mating surface skimmed and try 3rd time lucky :)
 

dac69er

Super Moderator
i guess we are talking about the exhaust mani?

what type of gasket are you using? if its not a genuine one then that is probably the problem.

otherwise go by dub-se7en's advice
 

Quick Nick

Member +
A very unusual problem so I would think outside the box and I cant think of any other reason this may be happening other than the warped mani idea. Get it skimmed, shouldnt cost too much.
 

Paul_JJ

Member +
Well in fact the mani has been replaced...... the first time the head to mani gasket was blown on Brand New WEPR after a few months of using it [I've put brand new nuts from Toyota, new gaskets from Toyota as well]...

then I've bought used Zisco of Danb87 and a very good mechanic who I trust 100% installed it WITH brand new Toyota Gaskets!!! It was Perfect for a few weeks.....

I still got my cat on may be that is the reason??? But I passed MOT on that and I don't have any smoke or anything from the exhaust even at high RPM! But then the car was designed to have a cat on in the first place...

May be it has got something to do with the nuts/studs????? Vibration????? the steering wheel vibrates on idle more than usual - only at idle - may be it has something to do with that??? However the engine mounts are good!

This is the 5th time is less than a year I have problems with my exhaust manifold (3rd now)......
 
Last edited:

Iain@CRD

Lifer
If your steering wheel is vibrating more than usual it could be a sign that your engine mounts are rather worn, what engine mounts do you use or have you checked them lately?

Its a very odd, never had a Head to Mani gasket blow that often, ive even reused them when ive taken them off and there perfect.

Are they blowing in the same area?
 

Paul_JJ

Member +
Engine mounts has been checked lately - perfect! The actual engine doesn't vibrate! It's original Toyota mounts. The vibration is on the car's radiator and it was on the standard air filter box [removed now]. It's only vibrates when idle and it doesn't vibrate at all if RPM is 1.5K or higher.

Yeah it seem to blow on the same side of the gasket in fact! It's on the passenger side and seem to come from the bottom of the mani not the top.

The steering wheel has been vibrating since I've bought the car, but I'm sure that it's more than usual cause I had a starlet before and I've seen the idle vibration on another Glanza. Everyone said that it's because I have a bigger exhaust, so I didn't think about it much! I have an HKS backbox!
 
Last edited:

Stu-

Member +
Pull the manifold off and hold a straight edge along the flange, it'll probably have a very slight deviation. That or the head may not be straight but thats a bit of a long shot. A local engineer should be able to run your manifold along a big belt sander to smoothen it out or even set it up and mill it (which I do for any manifolds I make). Bolts tightened enough?

Good luck!
 

Paul_JJ

Member +
Pull the manifold off and hold a straight edge along the flange, it'll probably have a very slight deviation. That or the head may not be straight but thats a bit of a long shot. A local engineer should be able to run your manifold along a big belt sander to smoothen it out or even set it up and mill it (which I do for any manifolds I make). Bolts tightened enough?

Good luck!

Thank mate!

Well yeah - that's another concern may be it needs more tightening! Another thing is may be put some silicone sealant (high temp one designed to use for the engine) on the gasket before putting a new gasket on? That should prevent it from leaking even if the engine head has a slight deviation... what do you think?
 

Stu-

Member +
I personally don't use any sealant and just use the metal gaskets - but saying that i'm running a 4agte not a 4efte and its been ages since I've seens a 4efte gasket. Just make sure both surfaces are super flat and you should be fine. Could always run two gaskets and make sure its torqued down really tight?
 

danb87

South East England Area Rep
paul, i told you too get it skimmed before fiiting it, too be safe. as you was already havin issues, with your previous ones. but as you was ina rush too get it on an mot you didn do this, remove it, get it done. plus ive always used the sealant myself with my manifolds, an on any gasket as just help with the seal.

when i did my head gasket we removed the studs from head an had the exhaust side machined also.but this was while the engine was apart so not too much hassle as was havin the head skimmed at same time.
 

Jay

Admin
Any advise where to look for the vibration issue? Would the exhaust affect it? How about gearbox mounts?

I've noticed the autos suffer from a greater vibration at idle that the manuals. Would still be worth looking at the gearbox mounts, especially the rear one as they are a common failure.
 
Top