Valve, lifter, or rod

[Rickster]

'79 C-10 250 with 3 on the tree
makes knocks until it gets warmed up.
Wonder how to distinguish between a vavle or lifter problem?

Anyone out there tried using engine flush before changing oil?
Just wonder if the stuff is worth pouring money into?

[usmcchevy]

how many miles are on the engine?

[1976Scottsdale]

Well, is it high or low pitched?  a lower pitch will be a rod knocking... and a rod wil knock all the time usually.  Sounds to me like a lifter sticking.  I have not had good experience with Motor Flush.  It will eat everything if you ware not extremely careful.  Buy some CD-2 engine treatment... not the MAX kind either.  Run the engine for a while and it should unstick the valve, if not, check valve lash.

[roundedline]

You can take a broomstick and place it on the motor in suspect places and put your thumb on the end and place your ear on it.  You should be able to hear where it is coming from.  

Diagnosing sounds over the internet isn't going to be easy...

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[Rickster]

There are 136,000 miles on the engine.

I would say the knocking has a low pitch.

Last Monday had a chance to listen to the engine with a long piece of tubing?  Believe there was some difference in the sound of the engine at the No. 1 cylinder versus the others.

Saturday a new sound developed.  A squelling sound.  The best I can deteremine the is sound is coming from the starter.  Why would I hear a sound at the starter unless it is coming from the...  Did not hear it at the bell housing.

See e-mail about mystery bolt.

Edited by: Rickster at: 7/15/06 7:01 am

[Rickster]

That noise I heard was from the starter since a bolt was sheared.  The allowed the starter to turn a bit and the pinion was rubbing the flywheel.

[Rickster]

How about that STP oil stablizer?  Any good or a waste of money?
Lucas, whatever, has a display in the auto parts stores with the gears and a little crank to demonstrate the vescosity.