seanb

I wanted to sell my car before moving out of state and someone asked for a compression and leak down test.

Well from my searches so far I can tell the numbers I got back are not very good.

1: 190psi
2: 170psi
3: 170psi
4: 165psi

Leakdown is 18 percent in all cylinders except one which is 13 percent.

Whats F'd up is it feels fine. Granted, I haven't driven other s2000s but it feels like it should be around 190-180 at the wheels(its in the 100s outside now..and I love my butt dyno).


So what can I do? Anything? I'd like to get it to where it should be before I sell it to anyone(that or take the hit in the price).

If anyone has any idea on what can be done, what does it entail? Cost of parts? Approximate labor hours?

I appreciate any advice I can get.

SilverKnight

dyno it curious to see what it would get.

sahtt

I'm not going to be able to tell you anything you probably don't know. The only way to get those compression numbers to spec is to rebuild the engine. It may just be the rings [500-600$], could be worse. You won't know until you at least take the head off. It is impossible to feel how much horsepower the car is producing to any accuracy. If you are confident, get it dynoed. If it dynos 195whp, your compression test dosn't mean much to most people. If you show them the dyno, they probably won't bother with a compression test. Are you sure the test was done correctly?

Based roughly on those numbers, I'd expect your engine to produce 170-175whp on a dyno that would produce 190-200whp on a healthy stock s2k. The problem is the rate in which your engine tolerances degrade is unknown. It may last a year with constant road racing, or it may drop to numbers in which the engine barely runs within a year of highway cruising.

My advice is to not sell the car under the impression nothing is wrong with it. Technically, you are doing nothing wrong legally, but it is immoral, and what goes around comes around, trust me. And speaking from a friend's experience, you never know what that buyer may do if a week later he has a 5k$ bill because you lied to him.

clawhammer

Did you do the compression and leakdown tests or did someone else do it? I'd have a different person re-do the tests. BTW, how many miles on the car?

xviper

That would be my first impression as well. Get a different shop to do it again and tell them nothing about the first one.

Slows2k

18% leakdown is pretty high, You most likely would have some driveability issue,(misfiring) or lots of oil burning (much higher than normal) with leakdown rate that high.

I'd definitelty redo both tests.

Greenlight

Did you have the throttle body open when you performed the compression test? Did you spin the engine until at least 5 compression stroke pulses elapsed with ALL of the spark plugs removed?

Also, the numbers may be a little higher if you check the compression/leak down with the engine at normal operating temperature.

The 18 percent numbers are a little suspect. With these numbers I would expect the engine to use a little oil between oil changes. Was the leak down tester a single gauge or a double gauge type? Was the reference pressure enough to zero (on some gauges 100%) the gauge?

In my experience a single gauge tester will normally read a couple of percent higher than a double gauge tester.

s2kBryan916

RadioZero

are these numbers corrected? would you mind butt dyno'ing my car? i am curious to see my numbers. how much and how many pulls per dyno? also, do you use an A/F sniffer up the tailpipe or up your butt?

LOL

seanb

the butt dyno was kind of a joke guys hehe.

I had it done by a highly reccomended tech here in Arizona. I didn't get to speak with him so I didn't get the rundown on the procedure.

If those numbers would represent some drivability issues I will probably get it retested. I haven't had any problems with driveability even with the 100+ temperatures outside.

The car just crossed 65k miles after driving it home from the shop yesterday. I think it is worth noting that I have only had the car since september and have only driven it 3500 miles myself so I haven't had years of driving it to compare. But it hasn't changed over those 3500 miles.

If the numbers really are that bad that would explain why I sucked so bad at autocross. I was down on power right guys?! hah

Since it drives fine I might just end up shipping it with me to Hawaii. I didn't really want to drop a chunk of change like that but I don't want to sell a potentially bunk car.

edit: crap I always for get something. Tests were done with engine at operating temperature. It was run until the fans cycled then tested. I at least know that since the tech typed that in on the service sheet. secondd edit..AND I haven't noticed any oil being used period. This is probably because I've changed the oil twice in the 3500 miles though.