I am looking for a good Corvette Engine Mechanic who can diagnose and repair an engine knock. I live in a Washington DC suburb and would like to find a mechanic within a 100 mi radius.

The problem is as follows: When the car is warmed up and driven, a loud knocking sound comes from the engine.

 

sounds like a spun bearing. meaning BIG problem.
did you recently do anything to the motor?
new cam? anything else you should mention?

how and when did it start?

 

:iagree: I doubt its preignition.

 

There was a good corvette mechanic at Phohanka (chevy) located in Chantilly VA but he left and went to the chevy dealer in Tyson's corner. Can't think of the name now. I would take it there.

The NVCC has there gernal business meeting there every month. they give directions to the dealership but don't list the name!!!! ahahah :lolg:

>>>
General Business Meeting
Event Type meeting
Date 2004-03-23
Time 07:30 PM- 00:00:00
Contact Jeff Kirk

nvccpres@yahoo.com
Where 2000 Chain Bridge Road

Vienna, VA 22182
Description General Business Meeting is for the general membership.
Directions Please park on the roof (Entrance in rear next to service bays). From D.C. - Take Rt.66 West to Rt.7 West exit. Go past the Tysons Corner Shopping Center. Dealership will be .5 mile past Center on the Left at the intersection of Rt.7 and Rt.123. From Virginia - Take 495 to Rt.7 West exit. Go past the Tysons Corner Shopping Center. Dealership will be .5 mile past Center on the Left at the intersection of Rt.7 and Rt.123.
<<<
http://www.nvcorvetteclub.com/nvcc/e...ode=view&id=43


[Modified by Bluewasp, 8:20 AM 4/24/2004]

 

Forgot to add criswell has some good vette mechanics.

 

Sounds like a bearing problem too. Probably a rod bearing, but not necessarily "spun", maybe only excessively worn.

Here's what I think is happening.

One of more of your bearings, probably rod, may have become extremely worn. This causes the oil clearances to open up. When the oil is cold, like when the engine is first started in the morning, the cold oil, being thicker, can fill the clearance (which is too great) and the engine sounds normal.

But after the oil heats up it thins out. Now the clearance can't be taken up by the thinner oil and the rod begins to collide against the crank journal resulting in the knocking sound.

If you keep driving it that way, you'll eventually lose the engine.

You can test my theory by draining the engine oil and pouring in a straight weight oil like Vavoline VR1 40 weight Racing oil. If the engine remains quite or at least remains quiet for a longer period of time, you can be assured it's a bearing problem that the heavier oil is masking.

Change the oil filter too and be sure to fill it with the new oil before screwing it to the block. Cut the old filter open with a hack saw and look deep inside the pleates for signs of silver and/or gold flake-like sparkles. If you see them, it's bearing material; further proof.

It can buy you some time but you definitely need to have the problem corrected ASAP.

Jake

 

I had a MORE Performance Head & Cam pkg installed 04/2001. The seating pressure on the valves weren't set properly and at 5,500 RPM a resonance started coming from the valvetrain. I had that corrected and the engine puts out 365 RWHP. I'm thinking that due to the incorrect seating valve pressure, some of the valves may have fatigued and need replacing &/or the lifters were damaged. The head & cam pkg was done at 40,000 miles on the odometer and the odo now has 59,000 original miles. I can't imagine a spun crank bearing.

But I am looking for a good engine mechanic; someone who can diagnose and repair the problem.

With a warm engine and the car having returned to an idle, after about 2 minutes of idling, the knock goes away. The knock doesn't return until after the rpm's have increased above idle.

The car doesn't burn a lick of oil. The oil is changed every 3,000 miles with Mobile 1 5-30.

 

I have heard about sooooooooooo many spun bearings after an LT1/4 cam swap I wouldn't doubt it.

 

I think I'll make an appointment for the Criswell Corvette Mechanic to take a look at it and get his opinion.