hello, was hoping to get some opinions on some compression numbers. As just some brief background, this is for a 2005 rx8 with about 58k miles that I am planning on buying, currently only money down. Also, I've been looking for almost a full year now, and this is THE BEST numbers I've seen...and even these aren't that good. At this point I think I'm going to compromise but wanted to get some opinions first. numbers are:


rotor 1: 7.7-7.7-7.7 @250rpm
rotor 2: 7.0-7.0-7.0 @250rpm


obviously rotor 2 is bad....but what the heck is with the difference between the two rotors?? Isn't there also some criteria that specifies minimum difference between the two housings? What are your thoughts on what could cause this drastic difference? Could there be a clogged/malfunctioning oil injector on housing 2? I'm sure that all of you are going to tell me to run, but again I've been patiently looking for so long that I'm convinced this is the best I’m going to find in my price range; also the rest of the car is in superb shape, garage kept all its life with one owner, and low mileage. Anyway, I'd be interested in hearing some of your thougts if you don't mind, I appreciate it thanks!

 

Did you seen the compression results? That seems like a bit of a coincidence that they are same across each face of each rotor...

In the end it really comes down to price, if the cost to buy it plus an engine rebuild seems fair to you then go for it.

 

Doesn't matter if compression is low by an inch or a mile, the cost to fix is the same. You may as well pay less for a fully dead car and put the price difference toward a new engine.

7.0 still has a bit of life left, but it's not going to get better. So.. Depends how long you want to keep thr car...

 

yes I thought the same thing...I'm just figuring that whoever did the test had very consistent numbers....like 7.1, 7.0 7.0 and just filled in 7.0 for all...and probably 248 rpm and just wrote 250....I'm going to try to contact the dealer and talk to the tester.



I agree with you. I've figured on replacing the engine no matter what I found cause I'm convinced there is no way I'll ever find an rx-8 without a crap engine...which is why I mentioned the great shape of the body, chassis and other parts of the car...and I know for a fact I'll prob never find an 8 with a dead engine but still with a good body....I know cause I've been looking for so long.


Anyway you've confirmed thoughts I've had as well, so thank you for your responses!


also any thoughts on there possibly being a screwed up oil injector on housing 2? If I get this car I'm gonna need to figure out what's screwing up housing 2...

 

I also find it suspicious that all of the readings are the same across each rotor. I have never seen that before. It could happen, I guess.

The rear rotor frequently goes first, because it takes the brunt of the heat and backpressure from a clogged cat, which I'm willing to bet that car has/had.

 

ok are there any symptoms that I could pick up on from a test drive to determine a clogged cat? lack of power? other than looking to see if the damn thing is glowing?

 

I think I'd rather remove the catpipe and see if you gain power than subject it to more abuse if it is clogged... and really if you are going to remove it then you can just look into it to see if it is clogged.

 

The only definitive test is to take down the front end and inspect it. It isn't hard to do if the bolts aren't badly rusted.

 

Thanks again for the responses



So why does the rear rotor receive more back pressure than the front? The exhaust streams merge together so why wouldn't there be an equilibrium of pressure?

 

Radiant heat?