Inlet / Exhaust Manifold Stud confusion
Posted: Wed Mar 11, 2009 2:34 pm
Hi All,
I've been reading all of the posts about the no.1 manifold stud as it seems that my symptoms point to this problem, but with all the seperate discussions I am now really confused so hoped someone could double check my working out before I go off and order lots of parts.
My bongo drives fine, but when it hits about 2,500rpm under load while driving I get a very loud and pronounced squealing noise which remains constant in pitch and volume until I back off the accelerator and drop below 2,500 revs where it goes away.
My garage aren't that experienced with bongos, but they have been doing servicing and an overheating problem as well as the front fan blowers rheostat issue - over the past 4 years. Now they seem to think that they have tracked the sound back to the INTAKE manifold on the elbow between the intercooler and the intake, and so they suggest that I replace the two gaskets to fix the problem.
So I checked on here at what more experienced bongo owners thought and it appears that there was a lot of scorn for a garage that suggested the intake gasket could even make this sort of noise and that the problem was either the EXHAUST manifold or the no.1 manifold stud shearing off.
Now my garage say they checked the exhaust manifold and are almost certain there is nothing wrong with it, so don't think there is any point in me ordering that part. They are sure it's on the INTAKE side ... though they did look at me a little blankly when I mentioned the exhaust manifold stud.
I noticed people describing the manifold stud sound as a chirruping or grasshopper, mine is a definite squeal - and also it is only when driving under load - wouldn't an exhaust manifold be constant? Somone also said on one thread that a leaking INTAKE gasket would be a ticking noise not a squeal - so I'm very confused now!
Is there any way I can check for this stud problem myself? Should I just order the replacement studs as well as intake gaskets? Oh and my exhaust back box just dropped off and there's corrosion on the centre section so I'm having to get both sections on order as well (could this be related to the squealing noise?)
Thanks all
I've been reading all of the posts about the no.1 manifold stud as it seems that my symptoms point to this problem, but with all the seperate discussions I am now really confused so hoped someone could double check my working out before I go off and order lots of parts.
My bongo drives fine, but when it hits about 2,500rpm under load while driving I get a very loud and pronounced squealing noise which remains constant in pitch and volume until I back off the accelerator and drop below 2,500 revs where it goes away.
My garage aren't that experienced with bongos, but they have been doing servicing and an overheating problem as well as the front fan blowers rheostat issue - over the past 4 years. Now they seem to think that they have tracked the sound back to the INTAKE manifold on the elbow between the intercooler and the intake, and so they suggest that I replace the two gaskets to fix the problem.
So I checked on here at what more experienced bongo owners thought and it appears that there was a lot of scorn for a garage that suggested the intake gasket could even make this sort of noise and that the problem was either the EXHAUST manifold or the no.1 manifold stud shearing off.
Now my garage say they checked the exhaust manifold and are almost certain there is nothing wrong with it, so don't think there is any point in me ordering that part. They are sure it's on the INTAKE side ... though they did look at me a little blankly when I mentioned the exhaust manifold stud.
I noticed people describing the manifold stud sound as a chirruping or grasshopper, mine is a definite squeal - and also it is only when driving under load - wouldn't an exhaust manifold be constant? Somone also said on one thread that a leaking INTAKE gasket would be a ticking noise not a squeal - so I'm very confused now!
Is there any way I can check for this stud problem myself? Should I just order the replacement studs as well as intake gaskets? Oh and my exhaust back box just dropped off and there's corrosion on the centre section so I'm having to get both sections on order as well (could this be related to the squealing noise?)
Thanks all