Slight Engine Tapping

[cjkeeliii]

I've noticed that for the past few weeks my '85 m1008's engine taps until it warms up. It seems to coming from the left (driver's) side. The truck has 94,000 miles. Any thoughts?

 

[67_C-30]

I've noticed that for the past few weeks my '85 m1008's engine taps until it warms up. It seems to coming from the left (driver's) side. The truck has 94,000 miles. Any thoughts?

Sounds like it could be a lifter. I had this happen on a '84 K10 I used to have. The good news is that it started doing it at around 280,000 miles and I sold the truck still fine at 339,000. Some people have had good luck with running Seafoam in the oil but I never tried it. Injectors can tap too, but I don't know if they would only do it cold.

 

[cjkeeliii]

How much misery is involved in changing lifters? Do these engines have hydraulic or solid lifters?

 

[Tanner]

The Famous 6.2 "lifter knock" - Diesel Place

GM-Diesel.com - 6.2 knock

'Tanner'

 

[JAsher45]

the worst part of changing the lifters is removing the fuel lines and valve covers. Once those are off remove the rockers, pushrods, the lifter retainer plates. the lifters are hyd roller lifters. GM makes a tool to remove them with out pulling the heads off.. just takes some time to fish them out. a good strong magnet will also do the job. take your time and it is not to bad to do.... I have had to do this to 6.5 engines on the dyno... amazing how much racket they will make when they quit or will not pump up

 

[raiburn]

If its not making a tapping noise, it mast be a gas motor.
These old diesels come from the factory with tapping noise.