Engine Vibration & Knock Sensor Question
Thread Starter
Racer
Joined: Feb 2001
Posts: 381
Likes: 8
From: NORTH WEST PA
Engine Vibration & Knock Sensor Question
I have an engine vibration starting at about 3400 RPMs and up. I have two questions.
1. Will engine vibrations cause the knock sensor to retard the timing?
2. What would cause this engine vibration?
I’ve had this car for six years and I know this vibration was not always there. The car had 107K on when I got it and now at 130K. Since owning the car I have replaced the water pump and this past summer replaced the OPTI and plugs. However, the vibration existed before replacing the OPTI and plugs.
To verify the vibration was completely engine related, with the car sitting still I slowly increased the engine RPMs until I noticed the vibration, which occurred at 3400 RPMs. Before tearing into the problem I am soliciting advice and any opinions.
Thanks!!
Brian
1. Will engine vibrations cause the knock sensor to retard the timing?
2. What would cause this engine vibration?
I’ve had this car for six years and I know this vibration was not always there. The car had 107K on when I got it and now at 130K. Since owning the car I have replaced the water pump and this past summer replaced the OPTI and plugs. However, the vibration existed before replacing the OPTI and plugs.
To verify the vibration was completely engine related, with the car sitting still I slowly increased the engine RPMs until I noticed the vibration, which occurred at 3400 RPMs. Before tearing into the problem I am soliciting advice and any opinions.
Thanks!!
Brian
Thread Starter
Racer
Joined: Feb 2001
Posts: 381
Likes: 8
From: NORTH WEST PA
Originally Posted by 500hp
6 speed or automatic?
Did you do the waterpump change? How many accessories/brackets were removed for the job? Were they all replaced correctly?
Did you do the waterpump change? How many accessories/brackets were removed for the job? Were they all replaced correctly?
The car is a 6 speed and when I replaced the water pump I only removed the water pump, no other accessories needed to be removed.
However, I did replace the plastic power steering pulley at that time because the original pulley had a chunk take out of it, and I replaced the belt with an original GM belt at the same time.
Thanks!!
Brian
Last edited by RED92LT1; Jan 1, 2006 at 10:29 PM.
Burning Brakes
Joined: Nov 2004
Posts: 781
Likes: 0
I wouldn't worry about the knock sensor pulling out timing if you are just experiencing vibrations.
As for the cause in your situation I would ask OTHER FORUM MEMBERS:
Has anyone out there ever had their dual mass flywheel 'wear out' enough to cause such a vibration? When I replaced mine with an aluminum flywheel, the dual mass had been replaced recently by the previous owner, so I don't have any personal experience with a 100,000 mile flywheel (or clutch?).
Also, to rule out the front accessories, have someone else rev your motor past 3,000 RPMs while you watch your belt to see if it is jumping around, and watch the tensioner, idler, and powersteering pulleys for skipping or momentary lock up. Loosen the belt, then reinstall it and make sure it is positioned within all six grooves on all the pulleys.
As for the cause in your situation I would ask OTHER FORUM MEMBERS:
Has anyone out there ever had their dual mass flywheel 'wear out' enough to cause such a vibration? When I replaced mine with an aluminum flywheel, the dual mass had been replaced recently by the previous owner, so I don't have any personal experience with a 100,000 mile flywheel (or clutch?).
Also, to rule out the front accessories, have someone else rev your motor past 3,000 RPMs while you watch your belt to see if it is jumping around, and watch the tensioner, idler, and powersteering pulleys for skipping or momentary lock up. Loosen the belt, then reinstall it and make sure it is positioned within all six grooves on all the pulleys.
Thread Starter
Racer
Joined: Feb 2001
Posts: 381
Likes: 8
From: NORTH WEST PA
I know the belt is riding on all six groves on all of the accessories. I agree with ruling out the accessory system, which I haven't done yet. As soon as I can get the car out I'll pull the belt altogether and see what happens.
The vibration is more noticeable under hard acceleration when driving the car, and sometimes it seems worse then other times.
Thanks!
Brian
The vibration is more noticeable under hard acceleration when driving the car, and sometimes it seems worse then other times.
Thanks!
Brian
