Compression & Leak Down Results - Advice Needed

[ClickClickBoom]

If you like the car and it has no unseen damage repairs, buy it. Those compression numbers are fine for a car that has been sitting on a dealer lot. Differential Compression tests are more of a trend monitoring tool. One time test is pretty close to useless. It has compression, buy it.

[Adam911Carrera]

Thanks for all the feedback and questions.

I am meeting with the dealer tomorrow and I have an email in to him about the engine numbers and some of the other items mentioned here.

I'm leaning towards making the purchase.

I will keep you all posted.

Anything else I should consider or look at when I'm there tomorrow?

[911 SLANT]

Make sure you know what your in for. The dealer your buying from deals with Exotic sports cars. They know what car is worth. I would be skeptical on why they are selling so cheap. Check the the numbers on body and motor and trans. Write them down and post on Pelican. Someone can check to see its authentication. Hopefully turbo flares are factory when car was ordered. If not and they are butt welded then might have a issue on value. I would definitely have a Reputable Porsche mechanic do a full run down before purchasing.
Don't let the good looks fool you. Good luck!

[ClickClickBoom]

Originally Posted by 911 SLANT

Make sure you know what your in for. The dealer your buying from deals with Exotic sports cars. They know what car is worth. I would be skeptical on why they are selling so cheap. Check the the numbers on body and motor and trans. Write them down and post on Pelican. Someone can check to see its authentication. Hopefully turbo flares are factory when car was ordered. If not and they are butt welded then might have a issue on value. I would definitely have a Reputable Porsche mechanic do a full run down before purchasing.
Don't let the good looks fool you. Good luck!

There is 25k in parts there, not a lot of risk...

[safe]

A factory turbo look (WTL) cabriolet would be VERY valuable.... There is collectors for these cars.
I don't think the VIN will tell a difference between a Targa or a Cabriolet.

[safe]

A WTL (option M491) would also have the turbos brakes. From 86 the fenders are a one piece, not a welded flair. This is things to look for.

But for 25k, just buy it... if your not happy I'll take it of you hands.

[Crude Rudy]

If you are having trouble shifting 1-2 or into 1st now you are saying its needs a trani rebuild too and while you are in there might as well do the clutch and axles too

Top end and trany/clutch at a shop you probably looking at $15-20K in work if not more at $150/hr labor rate

I would pass and find a car that all ready is sorted out for $35K if it was me

[nene]

Great info, but scary for the 1st time Porsche buyer.

Serge

[Locker537]

Originally Posted by ClickClickBoom

There is 25k in parts there, not a lot of risk...

I agree with you and Tony, but I want to play Devil's advocate.

Yes, there is 25K in parts.

However, if Adam wants to turn it into a reliable driver, the cost of rebuilding the engine, transaxle, all the little things, can quickly exceed the purchase price.

If that car was in pristine condition, what would it be worth?

Granted, these are often passion projects and the money is not the first concern, but I agree with knowing what you are getting into.

[aston@ultrasw.c]

80,000 original miles

Compression: 160, 142, 150, 150, 165, 135

Leak Down: 30%, 60%, 30%, 35%, 30%, 80%



IMHO the compression numbers are not great, especially for 80k miles - 280k miles maybe.

The leak down numbers are flawed. In theory the best you can get is 0% i.e. zero pressure leaking from the combustion chamber.

On an 80K motor *warmed up* I would expect 2% to 6% of leakage.

So 30% and 80% - is that 30% and 80% leaking

or 30% and 80% or zero leaking

Most owners would want an engine and trans rebuild in the near future.

I would go for the $35k truly solid example.

This is tough time to sell a car, if you really want it, try for another $5k off.

[Glenfield]

Adam, should definitely call the dealer and get answers before you go out there. That way this forum can help you value the potential of the car. You’ll be more knowledgeable on the car too and dealer might leave the skullduggery for someone else. Definitely get:
1. engine and transmission number and VIN number. All on the car and shop can get those in 2 minutes. With those, you can work out (a) if engine matches the production period indicated by the VIN and (b) if transmission is correct for the model too
2. VIN is good for an accidents report if post 1980
3. See if there’s an owners book or options list with the M491 option. That’s unlikely but would be gravy

There’s a world (that’s not too difficult to imagine) where you spend 25k on the car and then another 25k making it right. That’s a good trade if the cars worth 60k+. Not so much if it’s a Frankenstein as that will take some $$ before you can pronounce “it’s alive!”.

Ferdinand Magazine is a Porsche blog that has a good article on inspecting a car in person. Be a good one to read.

[ClickClickBoom]

Originally Posted by aston@ultrasw.c

80,000 original miles

Compression: 160, 142, 150, 150, 165, 135

Leak Down: 30%, 60%, 30%, 35%, 30%, 80%



IMHO the compression numbers are not great, especially for 80k miles - 280k miles maybe.

The leak down numbers are flawed. In theory the best you can get is 0% i.e. zero pressure leaking from the combustion chamber.

On an 80K motor *warmed up* I would expect 2% to 6% of leakage.

So 30% and 80% - is that 30% and 80% leaking

or 30% and 80% or zero leaking

Most owners would want an engine and trans rebuild in the near future.

I would go for the $35k truly solid example.

This is tough time to sell a car, if you really want it, try for another $5k off.

Differential Compression tests are a trend monitoring tool, and are subject to the skill of the mechanic. It is not a difficult test, but unless you rock the pistons on a operating temp engine, its a waste of time and energy. I have watched skilled, experienced A&P mechanics state an engine is un-airworthy, yet when I performed the test according to the Continental and Lycoming service bulletins, checks out fine. I have done more than a thousand of these over 30 years as an A&P.

[Adam911Carrera]

UPDATE: I bought the car today for $25K. Looks like we'll be chatting a lot in the coming weeks. Nice meeting everyone... I look forward to our future conversations!

[Trackrash]

OK. Now drive the car. Report back.

I am having a hard time believeing the leakdown numbers. IMO, if it is not smoking after warmed up and not burning a ton of oil, and if it doesn't have any broken head studs, you are good to go.

BTW, did the "mechanic" that did the leakdown check for broken head studs? Did he tell you where the air was leaking out?

Spend some time learning about the car and it's unique mechanics before considering any major repairs.

Here is a story similar to yours. There is a lesson to be learned here. Buy a 911sc they said. It will be fun they said ...

[nomore]

CNC motors, Upland CA. They have bigger fish on the fire than this Porsche. From the pictures on their website it looks like 25k is the mornng coffee run. They just didn't want to deal with the car that could have "problems". Good luck with it; and actually drive it before "fixing" it.

[Locker537]

Congrats on the purchase!

[safe]

Congratulations! Without seeing the car in real life it sounds like a good deal.

I would check valve lash, try some seafoam in the cylinders, have a good "italian tuneup" and recheck the leakdown, it might be stuck rings or something. Next leak down try to pinpoint where its leaking, rings or valves.

[ClickClickBoom]

Check the date:
Porsche heal thy self!