Help - Trying to make sense of PPI results on 86 Carrera (poor leakdown)
 

I just had an 86 Carrera inspected and despite the mechanic's praise of the car I am a little disappointed with the results.


Year 1986
Model:Coupe
Miles: 96,000
Color: Meteor Grey Metallic
Asking Price: $23,900

Current seller is the third owner and has the original window sticker, full service records, and documentation dating back to the original purchase.

When the current seller bought the car in 2002 they had a PPI performed. At the time the mileage was 84,000. Here are the results:

Compression:
1 - 125
2 - 128
3 - 125
4 - 125
5 - 128
6 - 125

Leakdown:
1 - 3%
2 - 4%
3 - 4%
4 - 3%
5 - 4%
6 - 4%

CO IDLE: .90 2500: .70
HC IDLE: 150 2500: .90
NOX: 0

No oil leaks, AC cold, rotors look new, breaks 50% front and rear, transmission shifts tightly, clutch feels great, suspension is tight, no play in steering wheel, no rust in body, interior excellent condition




The PPI results from today at 96,000 miles:

Compression:
1 - 135
2 - 135
3 - 125
4 - 140
5 - 140
6 - 140

Leakdown:
1 - 8%
2 - 12%
3 - 38% (exhaust)
4 - 7%
5 - 8%
6 - 4%

Spark plugs are in bad shape and need to be replaced, minor chatter in clutch, transmission shifts smoothly, shifter boot falling out, all pads good, very small lip on rotors, very dry engine, minor oil leak at center of case, cheap ground cable, needs break fluid flush, needs new rear sound deadner, small rock chips on hood and doors, needs new sunroof seals

Right front fender repainted, right door repainted, left rear quarter panel repainted



Speaking with the mechanic on the phone he was convinced that the poor leakdown on the third cylinder was caused by carbon buildup from lack of use. He also said the respray was one of the best he had seen. He said the car drives strong and overall it's one of the nicer 3.2's he's seen come in (8/10 overall).


I'm not sure what to think at this point. How concerned should I be about the poor leakdown results and the respray? Would asking the seller to send any records involving valve adjustments over the years bring any piece of mind about that 38% cylinder? There are a lot of positives about this car - the color, the service history, fairly low miles (especially over the last 10 years). I'm just not sure if they outweigh the negatives. What do you think? I have detailed pictures of every side of the car if you want to see something specific.


http://forums.pelicanparts.com/uploa...1377291616.jpg

http://forums.pelicanparts.com/uploa...1377291636.jpg

http://forums.pelicanparts.com/uploa...1377291675.jpg

http://forums.pelicanparts.com/uploa...1377291752.jpg

http://forums.pelicanparts.com/uploa...1377291778.jpg

Seems likely to me the bad leak down is an easy fix.

Sounds like the mechanic is sure of himself, so less likely that he screwed up the test, but still possible.

Possible a valve adjustment could help

Possible a stuck ring, or other issue that will clear up in a few hundred miles.

Suggestion, put a deposit on the car, drive it for the weekend, and retest.

Well, the compression improved so that tells me the first or second mechanic had incorrect gauges.

You are looking for large variances in these tests and #3 is large.

I don't like it, especially if you are paying good coin for the car.


Carbon buildup or not, it's a roll of the dice.

I'd say be skeptical.

Try and drive, and give the old girl an Italian tune up with some seafoam in the gas tank. Maybe worth the extra coin to have the mechanic re-do the leak down after that.

What did the spark plugs look like? Were they black from oil burning. Mechanic could be right about the carbon build up from lack of use. The flip side of that is, it may be like many 3.2's and need valve guides. Some were well worn with as little as 60,000 miles. It may not need the guides for a while depending on oil usage, but it will most likely need it done eventually.

Those compression numbers sound low. Search here for comparison numbers. I'd have to pull the docs to be sure but my PPI last year on my 86/135k miles car were in the 160-170 range.

The high leak down on one cylinder could be a valve guide or ring gone south or simply carbon bits keeping the valve open. I agree with the Italian Tune-up. If you are serious about the car it needs to be run good and hard before a follow up compression leakdown test. My car really runs better if occasionally beat on like a rented mule.

The pain looks good in photos but you have a lot of glare in them and that can hide the paint mismatch. Look at the paint in flat light or under flourescents. That will maximize any paint mis-match. FWIW the paint mis-match on the cars really only shows at the front and back of the doors. These are the only panel gaps that have same plane views.

Seems like it could be a nice car but I'd want to investigate the engine more before committing. -J

This, exactly this. No way I would buy the car with that leakdown number and "take a chance" without a significant discount.

with a leakdown they should be able to tell you if it is rings or valves. My guess is it needs valves and guides, 5k

I had a PPI with very similar results to yours. See this link. http://forums.pelicanparts.com/porsche-911-technical-forum/743933-help-ppi-revealed-one-bad-cylinder-airline-tickets-already-booked.html

In the end, the advice I tended to follow the most was drive it and see how it runs. If it makes you smile and does not smoke at start up or on hard acceleration, then it could not be too bad. Ask how many miles its been driven recently an consider a retest if possible.

I ended up buying mine, doing all the basic tune up items, and been driving as much as I can. No issues whatsoever so far.

That said, I know that an top end rebuild will be needed someday but to be honest that is the case on most of the cars I was looking at. Anyway, lots of advice in the attached thread that really helped me (still spent too much time thinking about it though:)

the compression numbers are low but I notice that you live in the snowy mountains where the altitude messes with compression numbers so it may be alright. If the price is right, buy it drive it and when you are ready, get a valve job done for 1500 bucks if you do all the labor except for the machine work.

Unfortunately I'm out of state so I don't think this is an option. Comparing both PPI's, and considering the fact that the car was only driven 1000 miles a year for the last 12 years, is it really possible for serious valve guide issues to develop over such a small number of miles on a car that is well taken care of?

If you were going to buy the car hoping its just carbon build up but aware that it might need some serious work in a year or two, what kind of price would you be happy with? Closer to $20,000.

Also is the consensus that the respray is not that big of a deal and does not affect the value much?

Thanks for all the advice.

I don't think that's bad as long as your oil usage is in a good place. If the one valve clears up with an Italian tune up you'd be fine...and I suspect the mechanic is correct considering it is just the one.
I've had a very respected Indy shop owner here in the Phx area tell me he doesn't worry about leak down in the low teens at all.
I'll bet if you drive it hard (after prop warm up of course) you'll see an improvement.