time for a engine rebuild? stock evo with 51k miles

what would be the most cost effective way to fix this problem?

 

What are the compression numbers?

 

How much lower is it than the other cylinders? Have u done a leak down test to try and pin point more of where the compression is being lost? Did all your plugs look normal?

 

I ran into this a week or so ago. Buddy and I were bored, decided to do a compression test. one cylinder came back with a scary number. I was stressed about rebuilds, burnt valves and all that. I took the car in to have a leakdown test, just to be sure. Came back with 1% across the board. Apparently I'm a hypochondriac with a fault compression tester.

Moral of the story, have a shop do a leakdown test. That will tell you where the problem is, or at least give you a good idea whats wrong.

 

IDK who did the leak down test but a brand new perfect engine will test 6 to 8%.

 

i had a similar issue with one cylinder 30psi lower than the rest. had a leak down test done by a good Evo shop and found a bad intake valve.

 

so its been confirmed, cylinders 1-3 are within 1-2 psi within each other but the 4th cylinder compression was 90. added oil and the psi jumped up within 1-3's range.

The weird thing is the car seems to feel,drive and idle fine, what would be common symptoms of low compression in 1 cylinder. and how soon should i get this problem fixed before something serious happens.

thanks for all the reply guys

 

probably a valve. get a leak down test done. i to added oil to the issued cylinder and the compression it went up so i thought my rings were jacked and i needed to do a rebuild. Lucky for me the leak down pointed to an intake valve.