Low Front Rotor Compression
 

Help! I just got my 8, which I have been wanting for 5 years... And it broke down!!
So I was on the highway and it lost power unless it had high revs.
I took it to a mechanic and he changed the oil lines because they rusted out which caused the problem he says. Now the compression in the front is 60% lower than the rear. It starts extremely rough, the gas pedal needs to be pressed the whole time, and it won't idle unless it's being revved. Any advice would be great!!

I assume no compression test prior to purchase?

Welcome to rotary ownership.

No not before the purchase. I know I should've now though. :( But after the oil hoses rusted through and were replaced compression became really bad. It drove fine before.

What are your compression test numbers?

The rear is 138 and the front is somewhere around 86-88

Those aren't compression numbers. That's just something somebody pulled out of their ass (or the equivalent by using the wrong tools).

A proper rotary compression test will have 8 numbers:
3 pressures and an RPM for the front rotor.
3 pressures and an RPM for the rear rotor.

I'm trying to figure out how rusty oil cooler pipes lead to bad compression. I'd start looking for other things like a vacuum leak or bad ignition components.

I had a feeling the oil pipes weren't leading to bad compression. I'm currently stuck in an area where all the mechanics are rotary air heads unfortunately. Thank you very much!!

Which is where? Perhaps there is a club member close...

I'm in Vermont right now.

Agreed you are correct, but even if they used a normal compression tester and the maximum psi on one of the three faces was 86-88 psi that will be a fail.

10:1 compression (14.7 psi x 10) = 147 psi perfect compression (just a hypothetical formula, obviously not taking heat/expansion into account)

Front rotor 87/147 = .59 or 59%
Rear rotor 138/147 = .94 or 94%

Even though its incorrect way to conduct a compression test, I can't see how a correct test would somehow overcome those numbers.

Mostly it's a matter of not trusting the result of somebody who can't do it right to begin with.

Put another way, if he can't be bothered to do the right test, how do we know he's even doing the wrong test correctly?

Also, based on OP's description, I don't really trust the guy's abilities.

If it's northern Vermont, I could come see it, but only after the 18th.

That's where I bought it, but I'm a pretty far drive. Im in east central Vermont.