Hello guys, recently bought an evo 9 gsr. Did the compression test on it and cylinders 1 and 2 were at 90PSI. Cylinders 3 and 4 were at 80 PSI. Also did a leakdown test and results were. Cylinder 1 15% at 100PSI. Cylinder 2 50% at 100PSI. Cylinder 3 35% at 100PSI. and Cylinder 4 15% at 100PSI. What would be the best route to fix this? If we are going to be needing to rebuild the engine, anyone got a rough estimate of what it would be. My goals on the evo is around 400HP. Dont want to get crazy with it. Thanks reading and would appreciate any feedback!

 

Hey, welcome to the boards @Thatkid385 & thanks for posting. Heres the compression spec from the manual for reference. How many miles on this motor?

 

165k miles on it

 

Yep, many hard miles im sure. Sounds like the rings & walls are well beyond the spec?

Possible rebuild IMO. Cost depends on many factors. Should you buy a completed short block? Are you going to do this yourself or local builder

Im not here to call this motor done, but just throwing out a couple of comments based on what this compression test noted. (if it was done correctly w/a proper accurate gauge & methodology?)

Something drove you to checking the compression, as if the motor was not pulling correctly under hard load?

 

The reason I did the compression and leak down test was to see how the engine is looking before I do any major mods to it. Currently it has an intake, full exhaust, ported intake/exhaust manifold, manual boost controller, and is tuned but not by the best here in my area. As for pulling correctly under hard load there is no problem there, it runs strong and pull hard no problems and no smoke out the tail pipe. Most likely am going to go with a local builder for a rebuild if needed.

 

Are these warm or cold numbers?

 

I didn't perform the test myself I had a shop do it. Id assume they are warm numbers.

 

The temp spec is this. Imagine if this shop did the check on a cold engine?

 

stock cams?

if not, mivec motors always read low

 

that was around the same compression as mine after a couple of years of tracking, I could feel a power drop on track days and others were commenting on extra blue smoke so that's when I did a compression test. It's important that you are convinced yourself that the motor needs a rebuild before you start down that rabbit hole as there's lots of directions to head down and all of them add up to alot of bucks.

 

The tests are an indicator, but since it's mivec and not knowing too much about the history it may be completely fine. May not need a complete rebuild. With high mileage engines history of maintenance is everything. It could be better shape than a motor with 40k miles or ready to crap out. All depends on previous history.

 

The car itself pulls hard and doesnt feel like its running weird. There isnt any blue smoke anywhere from the car when doing WOT. Im taking it with someone in my area experienced with evos. He suspects that the shop may have not done TDC on the 2 cylinders there for the bad test results. Hopefully the engine is healthy. If i gotta do a rebuild i just want something around 400hp and be reliable. It is not my daily but would like to be able to drive it often without having to worry about it being down often.

 

Just buy the tool and do it yourself if you don't trust a shop to do it correctly. It's SO easy. It's like $50 on Amazon.

I do this in parking lots at dealers for friends. It's literally so easy.

TDC only matters with leakdown test. Also easy to do yourself if you have a compressor.

 

Leakdown and compression are a static test. Things change "some" with the engine running.

If its making good power, not miss firing and not using a ton of oil I would just run it.

These engines are stout.

 

Redid a leak down test somewhere else. Got better numbers. Cylinder 1 and 4 at 15%. Cylinder 2 at 30%. cylinder 3 at 20%. Guy told me to just seafoam it to try and clean the gunk out from the valves and try and get to the valves to close better.