Manifold blowing
Discussion
Nearside on my '97. Sounds like a tractor when low revs high gear. The garage took the manifold off, machined the face flat and re-gasketed it. Still sounds like its blowing just as bad. Has anyone any experience of these cracking in between the branches? I cant see any crack, cant feel any blowing at idle, too hot to put your hand around there, too hot to put soapy water on it. Any ideas other than taking the manifold off and pressure testing it under water?
Is it a ticking sound you can hear? If so then most likely a cracked manifold. A very common problem on the Chims/Griffs due to the pants quality of the original TVR manifolds.
Replaced mine last year with ACT stainless de-cats (no precats in), they cost about £500 a pair and are far chearper than the OEM TVR ones. Plus they look a lot better when polished!
Replaced mine last year with ACT stainless de-cats (no precats in), they cost about £500 a pair and are far chearper than the OEM TVR ones. Plus they look a lot better when polished!
Agree with the ACT ones, but from memory, they do a refurbished, de-catted original manifold for about £250 a pair. Have a word with Tim at ACT, very nice to deal with.
As for testing the manifold, if you've got the thing off, the easiest way to check for leaks is to simply lay the thing on the ground and fill it with water (this won't damage the Lamda sensor BTW), leave it for a few minutes and if it's split at the point where the primaries meet, then you'll see the damp patch very clearly!
The nearside had split on mine too, unfortunately it's quite common so good second hand ones are rare. Running without pre-cats won't effect the MOT, or give you any extra horses, but i found that mine revved cleaner, and sounded better too.
Paul
As for testing the manifold, if you've got the thing off, the easiest way to check for leaks is to simply lay the thing on the ground and fill it with water (this won't damage the Lamda sensor BTW), leave it for a few minutes and if it's split at the point where the primaries meet, then you'll see the damp patch very clearly!
The nearside had split on mine too, unfortunately it's quite common so good second hand ones are rare. Running without pre-cats won't effect the MOT, or give you any extra horses, but i found that mine revved cleaner, and sounded better too.
Paul
It's probably a cracked manifold, your best chance to spot this was while it was off the car.
You have about a minute after you start the engine from cold, to feel around for exhaust leaks. Be cautious, because different bits warm up at different rates so moving your hand around after it has been running for a while be prepared to suddenly find a 'hot' bit.
You have about a minute after you start the engine from cold, to feel around for exhaust leaks. Be cautious, because different bits warm up at different rates so moving your hand around after it has been running for a while be prepared to suddenly find a 'hot' bit.
Best way to find your leak is to get a piece of 10mm (ish) nylon air hose or something similar. Stick one end of the hose down your ear 'ole and then go around the manifold with the other end. You will know when you find the leak. If you find that the leak is in the center of where the four pipes go into one then a temporary fix is to pack in a mixture of ceramic rope and gun gum, as much as you can. It worked for me. If you find a hair line crack in one of the pipes, and it is accessible, then this can be tig welded in position.
Sorry to drag up an old thread, just adding a link to this article on how to find leaks in the exhaust manifold.
Should be useful to anyone doing a search.
Should be useful to anyone doing a search.
I didn't know Alex had uploaded it. Hope you find it useful.Gassing Station | Chimaera | Top of Page | What's New | My Stuff