Rod Knock Question
Thread Starter
Melting Slicks
Joined: Mar 2002
Posts: 3,252
Likes: 6
From: The Colony Tx
Rod Knock Question
It has been 30 years since I had a Mouse with a bad rod and I can't remember if the noise was audible at idle or just when you reved the car up. Right now my son is having a knocking sound when the engine gets around 2000 rpm. This started after he broke a rocker arm. Unless the valve hit a piston, I don't think the could have caused a bad rod. Unless, maybe it was an exhaust valve and the pressure in the cylinder caused the damage. The engine probably has about 2k miles after a rebuild.
Also, any info on 'burping' the cooling system. Again, it has been a long time so I don't remember if you have to burp a C3.
Thanks in advance for any assistance.
Also, any info on 'burping' the cooling system. Again, it has been a long time so I don't remember if you have to burp a C3.
Thanks in advance for any assistance.
Instructor
Joined: Oct 2000
Posts: 137
Likes: 0
From: Flemington, nj 08822 usa
Re: Rod Knock Question (aj1988)
Rod knock is usually worst without load on the engine particularly when you back off the throttle rapidly from 2000 or so. It will "flutter" then settle down in time with the engine.
Larry
Larry
Team Owner
Joined: Sep 2001
Posts: 30,958
Likes: 0
From: Middletown Connecticut
Cruise-In IV Veteran
Re: Rod Knock Question (Larry3x2)
on mine, it was noticeable at idle.. sounded like a collapsed lifter. when you brought the revs up to about 1500-2500 you could distinctively hear it was clankin from down below
Racer
Joined: Jan 2003
Posts: 296
Likes: 1
From: Sarasota FL
Re: Rod Knock Question (aj1988)
For the saga of my rod problems see my series of last 4 posts. It is interesting and strange. I have a demolished rod and no eviednce of force anywhere else. The vaulve definitely did not contact the piston.
Marc80
Marc80
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Re: Rod Knock Question (aj1988)
My L-48 has a bad wrist pin on the #1 cylinder.
The knocking begins around 2200 rpms when the engine is warm-hot, most noticeable under low-load (cruising, or revving in neutral) conditions. It sounds fine when the engine is cold.
It has been like this since I bought the car several years ago.
Bubba (from whom I bought the car) had the crank turned and replaced the bearings, but then installed the old pistons and rods :rolleyes:
The oil pressure has always been good.
I have eliminated everything else it could be, so I am 99.9% certain that it is a wrist pin. I know it is the #1 cylinder because the knock goes away completely when the #1 spark plug is disconnected.
The knocking begins around 2200 rpms when the engine is warm-hot, most noticeable under low-load (cruising, or revving in neutral) conditions. It sounds fine when the engine is cold.
It has been like this since I bought the car several years ago.
Bubba (from whom I bought the car) had the crank turned and replaced the bearings, but then installed the old pistons and rods :rolleyes:
The oil pressure has always been good.
I have eliminated everything else it could be, so I am 99.9% certain that it is a wrist pin. I know it is the #1 cylinder because the knock goes away completely when the #1 spark plug is disconnected.
