View Full Version : Knock when dying...

12-01-2005, 11:45 PM
So, my engine has decided to make a new sound. When I kill the motor after warming it up, I get a "thump thump thump" as its dying. I can also feel the thump fairly well in my brake pedal.

Also, this sound is pretty hard to locate. I can't seem to hear it anywhere but in the cab. For example, if I have someone else kill it while I'm listening to the engine bay, I can't hear it.

Any ideas?

12-02-2005, 12:09 AM
mine comes from the fan, its loose and knocks on the surrounding case, I gotta get around to fixing that.

12-02-2005, 12:12 AM
I don't think that would lead to me feeling it in my brake pedal, though. I've been wondering if there's a component in my brake system getting ready to fail, and if their are other ways to determine that.

BTW, I don't have ABS.

Another thing I've wondered about is that maybe one or more of my engine mounts is/are going out, and the engine is bumping into something as it dies. However, I don't see to many other signs of aging mounts... The engine doesn't rock very badly when revved, etc.

12-02-2005, 02:04 PM
Sounds like it's dieseling to me. I would clean the fuel system.

12-02-2005, 04:40 PM
But dieseling requires that fuel be added to the cylinders... thats why its typically a problem with carbed cars. Does the EFI system continue to inject fuel after the ignition is turned off?

12-02-2005, 06:50 PM
No it doesn't, unless you have a leaking injector, which can happen, in that event it will diesel until the rail pressure falls off.

12-02-2005, 06:56 PM
Hmm. I wouldn't doubt that I have a leaking injector.

Is there a way to test for leaks without sending them out to a firm that does that sort of thing?

... and if it IS a leaking injector, is the only remedy replacing it?

12-02-2005, 11:37 PM
probably have to replace the injector.