Engine Knock!!!!!!!
Thread Starter
Team Owner
Joined: Oct 2001
Posts: 46,766
Likes: 5
From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Engine Knock!!!!!!!
2001 coupe with 20,000 miles. Just noticed that when car is started it's nice and quiet. About 1 minute of idling will bring on a knocking noise I think is coming from the top end.(noise gets louder until it warms, sounds like a diesel engine) When the engine warms to operating temp the noise goes away. Car is driven like I stole it maintained as it should be. Car has never made a sound does not burn oil nothing. What could it be? Just did an oil change went from 5-30 to 15-30. Any chance the change in oil is the culprit?
Bob
Bob
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
Re: Engine Knock!!!!!!! (16Again)
Bob,
Sounds like piston slap possibly.....piston expands as it gets hot so gets less noticable.
Oil should make no difference, but I think personally the Mobil 1 10w30 is better match.
:cheers:
Sounds like piston slap possibly.....piston expands as it gets hot so gets less noticable.
Oil should make no difference, but I think personally the Mobil 1 10w30 is better match.
:cheers:
Thread Starter
Team Owner
Joined: Oct 2001
Posts: 46,766
Likes: 5
From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Re: Engine Knock!!!!!!! (TLewis4095)
I thought piston slap as well but to start now at 20,000 miles?
I know I was reaching on the oil but I can hope it was something stupid like that can't I? :lol:
Bob
I know I was reaching on the oil but I can hope it was something stupid like that can't I? :lol:
Bob
Racer
Joined: Jul 1999
Posts: 256
Likes: 0
From: Euless TX
Re: Engine Knock!!!!!!! (TLewis4095)
Mine has done something similiar on occasion, I think it is a lifter that take a little while to pump up. I doubt it is piston slap since it takes a minute to start making noise. Try this- as soon as it starts knocking, bring the RPM's up to about 2500 rpm and hold it there for about 10 seconds to get plenty of oil flowing to the top end and see if goes away right away, does it evertime on mine. That really heavy oil may be taking alot longer to get flowing through the top end of the engine which may be why you just started noticing it. Personally, I wouldn't run that heavy of oil unless I was road racing or putting a similiar extreme load and temperatures on the oil since it will take longer to lubricate at startup which is where most wear occurs, but just my opinion :) Plus that weight oil isn't recommended in the owners manual which may cause warranty issues if they found out. :cheers:
Advanced
Joined: Apr 2002
Posts: 52
Likes: 0
From: Dallas TX
Re: Engine Knock!!!!!!! (yellowy2kc5)
I completely agree with yellowY2KC5. Not only do you not get the best oiling on cold startup with the thicker oil, but it's also very hard on your oil pump. I would recommend nothing heavier than 10w-xx for an LS1.
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☠☣☢ Semper Ebrius ☢☣☠
Joined: Jun 2001
Posts: 83,301
Likes: 4
From: Virginia
Cruise-In IV-V-VI-VII Veteran
St. Jude's Donor '06
Re: Engine Knock!!!!!!! (16Again)
My previous car, a 1997 Trans Am, had an LT1 with the same problem and it didn't show up until around 40,000 miles. It's just piston slap, you're safe.
Thread Starter
Team Owner
Joined: Oct 2001
Posts: 46,766
Likes: 5
From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Re: Engine Knock!!!!!!! (Scissors)
My previous car, a 1997 Trans Am, had an LT1 with the same problem and it didn't show up until around 40,000 miles. It's just piston slap, you're safe.
Bob
