Knock Down Below

[bretamo]

My 92GT has had a knock for couple of weeks, and I attacked the problem this weekend as if it was a rocker arm hitting the valve covers.

I did this partly because I've been wanting tall FR covers and a 1" spacer fro a while, so I put them on and also removed all the smog equipment and plugged the holes. When I removed the upper intake and valve covers to inspect the rocker arms and rods, I did not find any that were loose our unusual.

I have GT-40Y heads with steel Comp Cam roller on stud mounts, and I did not find any of them rocker arms loose or anything unusual under the valve covers.

After I put things back together, I noticed things a bit quieter with the smog equipment gone, but the knock was still there.

The knock is more noticeable when I am below the car, and the sound draws me to the crank or the water pump/timing chain area of the motor.

Any advice with this? With over 200k on the motor, my thought is that its going to need to be pulled and worked over.

 

[bradranger]

knocking

yes my brother has the same problem with his mustang and it sounds like its in the bottom of the motor. Now we were told that most likely its a crankshaft bearing going bad. So I hope that this isn't the problem, but dosen't sound good. Good luck in finding out.

 

[bretamo]

Sigh of Relief?

I took advice from another post, and I think I have a sigh of relief in that I do not hear a knock when I run the engine without the serpentine belt.

This tells me I have a accessory or water pump knock, which is a lot easier to handle than a lifter or bearing inside the motor.

What's the most likely cause of an accessory knock that sounds somewhat like a rocker arm hitting a valve cover?