I have a chirping sound from the engine... there is a repeating rhythm to it.
The belt is adjusted properly.
Just had the valve cover gasket replaced and the gasket for the distributor replaced due to oil leak.
While snooping for source of this noise, I have noticed a dribble coming from the thermostat housing.
Vehicle has 216000 miles, I have owned it since 1997, oil and filter has been changed every 3000 miles.
Has anybody else had this chirping or possibly identify what it is.
Thanks in advance..

 

Mine does that from time to time when it's cold and I first start it up. It's probably a bearing on one of the accessory pulleys.

 

A chirping sound is often a pulley, so check them all. For my engine,
which wasn't a 4.0, it meant a bad water pump.

 

Pull the belt and check the pulleys by hand. I did that for my 97 after it started chirping and found the tensioner was shot. I would also check the balancer. IF the rubber ring is worn, the outer hub can walk back into the timing chain cover. If left alone, it will chew right thru it. I never had that so i dont know how much of a chirp that would be, but i think its worth a look.

The thermostat housing dribble could be cracked or warped, the bolts worked loose, or the gasket sprung a leak. Doublecheck the hose clamp. Ive been fooled by those more than once.

 

Hi!

When it's chilly and I initially start it up, mine does that from time to time. It's most likely a bearing on an additional pulley.

 

Yup...you hit it right on the head. The crankshaft pulley (harmonic balancer) rubber had deteriorated to the point that on a quick acceleration the outer ring slipped. Glad it didn't happen on a long road trip.... thank you and to all that replied. Made it easier to figure out.

 

So nice when a story ends well.