Compression Test
Posted: Mon Sep 19, 2016 9:47 pm
Well, since my Jeep decided to burn oil at Potts all day I decided to do a compression test to see how the motor is doing.
Commonly on the 4.7's the valve stem seals will fail and smoke considerably when idling and under de-accelation. Which I'm thinking this is my issue but still good to check compression anyways.
Conditions were as follows, a hot motor with the fuel pump relay pulled. Injectors were still firing but that shouldn't make a difference. Pulled all the plugs at once to test as well. This was also a dry test expect for one cylinder that read a hair lower I added a few drops of oil and the compression numbers increased slightly. Here are my results below, honestly I think they looked good expect for one but it was cold at that point, had to walk away from it for 2 hours. But I'm not sure how much of a difference it'd make.
Also I may have a slight head gasket leak according to the last oil analysis but it isn't definitive. Will see what happens on the next oil change soon.
Commonly on the 4.7's the valve stem seals will fail and smoke considerably when idling and under de-accelation. Which I'm thinking this is my issue but still good to check compression anyways.
Conditions were as follows, a hot motor with the fuel pump relay pulled. Injectors were still firing but that shouldn't make a difference. Pulled all the plugs at once to test as well. This was also a dry test expect for one cylinder that read a hair lower I added a few drops of oil and the compression numbers increased slightly. Here are my results below, honestly I think they looked good expect for one but it was cold at that point, had to walk away from it for 2 hours. But I'm not sure how much of a difference it'd make.
Also I may have a slight head gasket leak according to the last oil analysis but it isn't definitive. Will see what happens on the next oil change soon.
Yeah that is plan mmm "E" or "F" right now lol. Plan "A" hasn't even happened yet.