Hi Guys,

I decided to do a compression test just out of curiosity last weekend on my IX that has 51k miles. (I performed it correctly... warm engine, WOT while cranking for at 6+ revolutions). My results are out of spec. The service manual says between 145 psi and 92 psi is ok as long as they are all within 14 psi of each other.
Here are my numbers:

108, 111, 135, 125 (so... 135 - 108 = 27)

Then I added a cap full of oil to each cylinder except for the one that measured 135 psi, then I got:

160, 145, (135), 141

So, from what I have read, that means my rings are bad. Now what???
She runs pretty strong, makes good power... Do I need to do anything at this point? Is it bad to keep running like this? Could I be losing power? Gas mileage?

Thanks!

 

Do a leak down test do determine where you're losing compression.

 

btw if adding oil doesn't raise compression it can't be rings. If it were rings, assuming it wernt something else like ex. Intake valves, seals, or exhaust. Headgasket etc... Then compression would rise.

 

Just realize that you will need a rebuild and plan accordingly. It isn't a big problem but it isn't right by any means. You could have issues like popping the dipstick or smoking. You are probably down on power too. But if it runs good to you then rock it until you have the means to fix it. You at least won't be caught off guard if it does go southin a hurry.

 

I would run it until it stops or is low on power. In the mean time, build a 2.4 or 2.1 so you have something to swap when it stops running. Then sell your block and crank for extra cash to pay for your built motor.

 

How many miles? Try a can of seafoam.

 

I have 51,000 miles now... I am second owner so 30,000 of them are mine. I am not really familiar with seafoam... pour it in my gas tank as a fuel treatment to clean deposits? can you explain your theory how that might help? thanks.

 

You can also pour it into the head via a vacuum line(to the cylinder head/valve cover)...not sure which one..there is a How To you tube and even on here, EvoM. It COULD help clean out any sludge etc....you'll need an oil change less than 100 miles of going this route. I would do it sooner then that but this is ONLY what I've read...never tried it myself. I've only put it through the tank and it did run better for with the high miles I have on my evo.

GL!

 

Seafoam will do nothing for you. Do a leakdown to see where you are leaking what. Better to save it now.

 

If it runs fine and has no weird noises I really wouldn't worry about it. Unless you have another car and wanna build it there is know point in ripping apart at this point.

 

Is a leakdown necessary? Isn't it safe to say its my rings since the numbers were all good after adding the oil?
I know it wouldn't hurt to do it, but I don't really want to buy a leakdown tester if its just going to tell me what I already know...

 

But you said you didn't add oil into the cylinder with low compression?? Why not? Dry and wet compression test is step #1 to find the problem. Leakdown is step #2. To be completely sure where your losing compression.

What's if it's a intake or valve seal and that's all....you never know. Don't throw rocks at what it might be, diagnose it properly.

 

He did add oil on the second test.

 

Its going to be down in power and maybe run a little rough. If that's not bothering you, drive it. So, agree.

 

He did add oil, but he said "except to the one I got 135psi"...