What do these engine measurements indicate.
Posted: June 16th, 2017, 5:56 pm
Hi folks this is my first post, Just bought a 4.0 manual 2006 TJ. The jeep has had it''s original engine replaced from a desert rally TJ, but previous owner is not sure of any mods to the engine.
I have been measuring the vacuum on this engine and record vacuum at 17.8 to 18.1 inhg. I am using a vacuum gauge connected to the vacuum line on the brake booster vaccum hose and used the hvac vent controls port. From this I suspected piston rings worn, so did a compression test.
These are my compression readings,
1 155ps
2 165psi
3 155psi
4 167psi
5 163psi
6 160psi
Readings are above the factory spec of 150psi max, but within the variation range between cylinders. Is my engine modified from factory. The vacuum should be above 20-22 inhg right?
I have been measuring the vacuum on this engine and record vacuum at 17.8 to 18.1 inhg. I am using a vacuum gauge connected to the vacuum line on the brake booster vaccum hose and used the hvac vent controls port. From this I suspected piston rings worn, so did a compression test.
These are my compression readings,
1 155ps
2 165psi
3 155psi
4 167psi
5 163psi
6 160psi
Readings are above the factory spec of 150psi max, but within the variation range between cylinders. Is my engine modified from factory. The vacuum should be above 20-22 inhg right?