bad knock under acceleration
Thread Starter
Instructor
Joined: Jul 2004
Posts: 118
Likes: 0
From: Smithfield Va.
bad knock under acceleration
When under heavy load from low RPMs I get what seems to be a loud rattling sound from the engine. ('90 L98) Sounds like it's coming from the top but I can't be sure. It started doing it all at once one day during a rain storm. One of my mufflers had deteriorated and I removed it until I could replace it. I don't know if that mattered. Every now and then it causes my check engine light to come on and the only code I get is "knock sensor." Most of the time it subsides when I back off the gas. What could this be?
Le Mans Master
Joined: Jun 2002
Posts: 6,307
Likes: 36
From: DSM IA & Lake of the Ozarks
Originally Posted by brian pinner
When under heavy load from low RPMs I get what seems to be a loud rattling sound from the engine. ('90 L98) Sounds like it's coming from the top but I can't be sure. It started doing it all at once one day during a rain storm. One of my mufflers had deteriorated and I removed it until I could replace it. I don't know if that mattered. Every now and then it causes my check engine light to come on and the only code I get is "knock sensor." Most of the time it subsides when I back off the gas. What could this be?
Do you have a 6-speed or auto trans?
Thread Starter
Instructor
Joined: Jul 2004
Posts: 118
Likes: 0
From: Smithfield Va.
automatic trans, and I'm using 93 octane. i had my mechanic check it with his computer and seems like the engine computer was adjusting the timing a lot. didn't come up with any conclusions though...maybe a sensor? i did replace the EGR valve and the computer. It doesn't do it as much, but still does.
Last edited by brian pinner; Aug 9, 2004 at 05:55 PM.
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by brian pinner
One of my mufflers had deteriorated and I removed it until I could replace it.
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