Spun rod bearing?
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 46
Likes: 0
From: CT Shore
Spun rod bearing?
I left for lunch today and noticed a odd noise in the engine area of my coupe.
At idle the engine has a minor clunk or rap that did not exist before. It is similar to a loose heat shield virbation.
at 2500-3000 RPM the noise is considerably louder (and increased frequency, of course).
I'm too concerned to increase the RPM above that until I find out what the cause.
I have isolated it to the engine, clutch or driven accessories as it does this in neutral (parked)
I have not had any indication of oil pump failure and when cold the pressure gauge indicates ~50PSI. Hot engine idles @ 20PSI and increase to 35PSI around ~1500 RPM.
Oil level is "FULL" cold.
Anyone with similar symptoms? I am thinking that a rod bearing has lapped (spun).
98 coupe MN6 30K miles
Completely stock
Mobil One oil (2000 miles since last change)
Regards,
Doug
At idle the engine has a minor clunk or rap that did not exist before. It is similar to a loose heat shield virbation.
at 2500-3000 RPM the noise is considerably louder (and increased frequency, of course).
I'm too concerned to increase the RPM above that until I find out what the cause.
I have isolated it to the engine, clutch or driven accessories as it does this in neutral (parked)
I have not had any indication of oil pump failure and when cold the pressure gauge indicates ~50PSI. Hot engine idles @ 20PSI and increase to 35PSI around ~1500 RPM.
Oil level is "FULL" cold.
Anyone with similar symptoms? I am thinking that a rod bearing has lapped (spun).
98 coupe MN6 30K miles
Completely stock
Mobil One oil (2000 miles since last change)
Regards,
Doug
Drifting
Joined: Sep 2000
Posts: 1,456
Likes: 5
From: Bothell WA
Re: Spun rod bearing? (Black-C5)
If it were my car, the next thing I'd do is drain a little oil from it and look for any type of metal particles in it. I spun a rod bearing in my '93 LT1 engine a while ago before I got my C5. It had a noticable abount of fine metal in the oil that made it "glisten" in the light. I hope this turns out to be something simpler.
- Mark
- Mark
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 46
Likes: 0
From: CT Shore
Re: Spun rod bearing? (Mark VerMurlen)
Fully engaging the clutch has no effect, in neutral or in gear. I started the car (idle) this morning to check that and something definitely broke inside the engine. It sounds like marbles in a coffee can. Oil pressure went very low and but increases to 20PSI with a slight increase in RPM. I heard the DIC warning and immediately shut the car off. My guess is a rod or cap is broken.
I bought a new oil filter and will cut the old one open to see if there is any bearing material or metal debis in the filter.
Guess I'll start looking for stoker kits if I have to get a new crank/rotating assy.
[Modified by Black-C5, 7:57 PM 8/21/2003]
I bought a new oil filter and will cut the old one open to see if there is any bearing material or metal debis in the filter.
Guess I'll start looking for stoker kits if I have to get a new crank/rotating assy.
[Modified by Black-C5, 7:57 PM 8/21/2003]
Melting Slicks
Joined: Aug 1999
Posts: 3,452
Likes: 3
From: Spring, TX
Re: Spun rod bearing? (Black-C5)
I would drain the oil and run it through a coffe filter or paper towel. You know what I mean and see what shows up. Large pieces will indicate a rod or possibly a camshaft failure. Fine glitter like particles would indicate a bearing failure. A bearing failure will allow the big end of the rod to move around contacting adjacent rod and cranshaft making one hell of a racket. I would not run the engine further.
Le Mans Master
Joined: Jul 2002
Posts: 7,370
Likes: 8
From: Slave to the evil empire
Cruise-In V Veteran
St. Jude Donor '04
Re: Spun rod bearing? (gonbad)
I would drain the oil and run it through a coffe filter or paper towel. You know what I mean and see what shows up. Large pieces will indicate a rod or possibly a camshaft failure. Fine glitter like particles would indicate a bearing failure. A bearing failure will allow the big end of the rod to move around contacting adjacent rod and cranshaft making one hell of a racket. I would not run the engine further.
Good luck
