- posted
17 years ago
engine knock 88 240 non turbo
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- posted
17 years ago
It is not knock if it is at idle. You have a leaky exhaust manifold gasket. The reason it is louder at startup is because the manifold has not expanded to partially seal the leak. You should be able to see carbon deposits around the leak. Replace all four exhaust gaskets.
Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs (among other things)
void _-void-_ in the obvious place
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- posted
17 years ago
Maybe, or maybe it's piston slap. Well known phenomenon in B230 engines. Not familiar with it myseslf, but it's said to be worst when cold, and diminishes as the engine warms up.
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- posted
17 years ago
I agree, not rod knock because it quiets after the exhaust gets really hot. In my experience, exhaust leaks are a fairly sharp tapping sound while bad rod knocks are a deeper "thunk" sound. Mild rod knocks sound very much like exhaust leaks, though. Piston slap is louder when the engine is cold, but it quiets quickly. It also sounds deeper than an exhaust leak, more like a clank.
My favorite technique for locating an exhaust leak: Start with a cold engine. Connect the hose of a shop vac to the outlet side of the vac, so it is blowing air. Empty the shop vac and run it for a few minutes to clear grit out of the hose. Duct tape the hose to the exhaust pipe of the car and start the shop vac. Feel around the exhaust with your bare hand - even a small leak will be obvious.
Mike
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- posted
17 years ago
I know for sure that the header pipe is leaking right at the manifold, and it is a bad leak. I need to replace two of the studs, and I am holding of until I do the rear seal, which is also leaking. I have new motor mounts and was going to yank the motor and tranny together to do all of this and some other stuff. (correct timing belt,I think I'm off a tooth,fix leaky water pump gasket,front tranny seals, rewire overdrive selonoid to switch) I have a list. Thanks Ray
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- posted
17 years ago
There ya go! Drive with confidence, but remember the exhaust at that point has significant CO. Having had CO poisoning once, I can tell you it's bad news. The sound you describe should be trivial enough, but if it gets louder it may need attention earlier.
Mike