JHZR2
Staff member
Hi,
Curious of the pros/cons of hot versus cold compression tests. For example, on the MB TM, the compression for diesel engines should be done with engine temperature no less than 70C.
However, Ive heard that a cold compression test can be more telling in some ways than hot. Also, for example, that a hot test tells you some things, but a cold test tells you everything.
FWIW, I was changing glow plugs on my 82 and got the following cold:
Cyl 1 380
Cyl 2 385
Cyl 3 375
Cyl 4 355
Cyl 5 375
Not sure if I had a slightly poor seal on #4, there is an issue, or it is just a valve adjustment issue...
The 617.95 service manual lists normal compression as 24-30 bar. Minimum is 15 bar. Maximum difference between individual cylinders is 3 bar. (These figures are with the engine at normal operating temperature.)
Your thoughts?
Thanks!
Curious of the pros/cons of hot versus cold compression tests. For example, on the MB TM, the compression for diesel engines should be done with engine temperature no less than 70C.
However, Ive heard that a cold compression test can be more telling in some ways than hot. Also, for example, that a hot test tells you some things, but a cold test tells you everything.
FWIW, I was changing glow plugs on my 82 and got the following cold:
Cyl 1 380
Cyl 2 385
Cyl 3 375
Cyl 4 355
Cyl 5 375
Not sure if I had a slightly poor seal on #4, there is an issue, or it is just a valve adjustment issue...
The 617.95 service manual lists normal compression as 24-30 bar. Minimum is 15 bar. Maximum difference between individual cylinders is 3 bar. (These figures are with the engine at normal operating temperature.)
Your thoughts?
Thanks!