from this thread

https://www.evolutionm.net/forums/sh...d.php?t=348617

so we did a compression test and the results were as follows

120 125 145 145

i did all 4 cylinders the same way and i even re-did one and two to make sure i had all the air fittings tight. and thats as high as they got.

we took it out and he was only boosting 1 bar or 14.7psi. now this is a 06 with 8000 miles on it. it should be spiking 21 psi and holding 17 correct?

step 2 i did a boost leak test and found that the throttle body was leaking. this happened to mine as well but mine had 35,000 on it. so i started to move the butterfly valve when it was leaking and the air leaking out would stop, then leak out, then stop ect.

so can we safely say that this is the throttle body shaft o-rings? i replaced mine with the works ones, and let me tell u it was a ***** pressing those seals in without a press.

insert thoughts here ______________

 

Did you put a little bit of oil in the cylinders and then repeat the compression test?

 

no, y would i do that? i have never herd of that b4.

 

Many times I have had people think the tbody seals were leaking when actually the t/body gasket was or the coupler was. I find this happens more often than the seals leaking. I am not saying yours werent' though, just pointing out what I have noticed.

Those compression test numbers would have me very concerned. Next step is to do a leakdown test. This will help you pin point and problem areas.

 

The point of the oil is to see if it bumps up the compression. If the compression get a lot better it is a good indication it is the rings. A leak down test is more accurate though.

 

reason i think its the TB shaft seals is because when u move the tb back and forth and open it, the leak (hissing) will go away, then come back and so on and so forth.

also i checked all his stock clamps and they were all loose. the one attached to the TB was actually stripped. so i advised him of this.

as far as a leak down test, i have never performed one and i will do a search on how to. thanks.

 

I would def. perform another Compression test, only this time squirting a little 30wt oil in each cylinder first as stated. This simply temporarily seals the rings, and if the compression number rises, then you more then likely have a bad ring. If the number stays the same, then I would say it's a bad valve/seat. This is when the Leakdown test comes into play! Good luck, and I hope everything works out .

 

Since 1 and 2 are nearly the same, could be leak at the head gasket too.

 

yes i will see if he wants to do this. how much oil should i add?

will the dealer do a leakdown test? i searched and didnt find any how tos or anythiung like that.

 

Not much at all, just a little squirt. It doesn't take much to temporarily seal the rings (if that is infact his problem). The dealer should certainly be able to perform a leak down test.

 

Search the internet not Evom. You'd be better off having a professional do it though. I'm sure your dealership could do it. I'd rather have a speed shop do it. It's pretty easy to do, but I've seen some clueless Mitsu techs.

 

Did you do a compression test while the car was warmed up?

 

Yeah, the method of the test could make the results vary quite a bit. Just in case you didn't know:

1. Engine Warm
2. All spark plugs removed
3. crank while at WOT

I usually crank for around 7-8 revolutions.

 

yes we did all that. when i was taking the spark plugs out, they were hot! took them all out, un-hooked crank and cam position sensors, counted 1,2,3,4,5 mississippi's.

 

only 8000 miles?!? how does that happen?



edit: your buddy should have gotten a compression test before he bought it *super sad face*