05 with low compression

I am currently looking at picking up an '05 LGT with 120K+ on it... I have seen the compression numbers on it 125-128 in 1-3 but cylinder #4 is near 80 ... It currently is moded to stage Sure2Fail... Including FMIC, 18G turbo, TGV deletes and a nice list of other supporting mods. I am all schooled up on banjo filters and cated uppipes but have limited knowledge on engine internals... I am aware of the 2.5's ringland failure in cylinder #4 so that is what I suspect is the problem here... I am not able to do a leak down test to confirm until I buy it and have it shipped here...

I guess what I am wondering is...
A). would cylinder 4 have a ringland failure bad enough to score the block at 80 psi?
B). Is a burn valve a common problem on the 2.5's?
C). If I pull the block to rebuild it what would be the worst case?
D). average cost to do a rebuild that can handle around 450-500 WHP yet still be reliable?

I'd bet money that it is the ringland. 80psi normal to high normal for a ringland issue.

To do it right, I'd budget $4k plus, particularly if you want to put forged pistons in, which you should if the engine is open. I think mine cost $5kish (the bill was higher, but I also had to rebuilt the transmission and put in a front LSD). My short-block was reusable.

For D, I would suspect more money.

I'm assuming you're buying this car assuming you need to redo the whole thing.

Just found out about the low compression today... so I am trying to figure out what it will cost and what I have to worry about before I make him a new offer.

Originally Posted by Subie Lovers

Just found out about the low compression today... so I am trying to figure out what it will cost and what I have to worry about before I make him a new offer.

I'd drop the price by at least $5k.

tell him you will tow it for free.

I just had a compression test done today on my 05, and they didn't even do the wet test, just dry. 1-4 was 140-130-135-130. The spec calls for 142-171psi with an 8.0:1-9.5:1 ratio (not quite sure what it means, still researching), so I'm not terribly worried.

With my wanting to go from stage 0 to stage 2 immediately after deployment.. I may hold off and do a cheap rebuild.. seals and gaskets and such. Depending on what I have available to me, I may go for a full advanced rebuild, and gut the whole thing and piece together a true monster.

I don't know, just throwing it out there.

I wouldn't worry about those numbers at all.
Every single compression test is done differently. 140-130 across all 4 is pretty darn good. I wouldn't waste money on a rebuild.

Originally Posted by nm+

I wouldn't worry about those numbers at all.
Every single compression test is done differently. 140-130 across all 4 is pretty darn good. I wouldn't waste money on a rebuild.

I just had a compression test done a few weeks ago...about 140 in cyl. # 1 & 3, and about 132 in cal # 2 & 4, AND it passed the leak down test. We opened the motor anyway due to the oil consumption (1qt every 300 miles). Guess what, ring land failure! So even a good compression test can mask the issue. I just bought my car in May, and there was no way to tell what problem was waiting for me. It drove good, engine seemed healthy and was pretty smooth. I have a thread in the 4th gen forums with pics. The ringland on number 4 had a pretty big chunk broken off, #2 was more cracked with a small missing piece.

OP, a new short block is slightly over $1800 shipped. Then you have to decide whether or not you want forged pistons (this being my DD, I did not go forged). Then you don't want to put on an old oil pump, or old timing belt, so you're going to want to buy those. New head studs would be a good thing, and new oil control valves since it's apart. Then the head needs to be machined, maybe even more once you have it apart. You'll need a new gasket kit too. Then there is labor. It's going to cost $5k-$6k. We found shaft play on the turbo, you may run into that too, so a new turbo with labor can put you close to $7k. I would low ball the price real well because you will spend a lot to get this done. I wish I new the issues this car had to offer the proper low ball price this car deserved. My saving grace is that I bought a full coverage warranty for $1330 for 4yrs/48k miles, and they approved the repairs yesterday. On the flip side, once it's all done, you essentially have a new car. Get a better tune, take care of it, and hopefully it'll run great. That's my hope.