PPI - compression test/leakdown - to do, or not to do?
 

In shopping cars and talking to Porsche owners and mechanics, I have run into two opposite reactions in response to the question of whether or not to automatically do a compression test/leakdown as part of a PPI.

Many buyers/sellers/owners say, "Be sure to get it on older cars, don't buy it if they won't let you check it" etc.

However some of the mechanics I've talked to have not been so quick to recommend or even insist on doing a compression test/LD. For example, one mechanic I talked to said he'd be happy to do a compression test - IF I insisted, but that by driving the car, looking at it and listening to it, he would be able to tell whether the car had problems that would require further diagnosis with compression test/LD.

"Don't buy it if they won't let you check it" does make sense to me, esp if there is obvious reason to want to check. But if the owner doesn't know the mechanic (which we hope they don't if we're getting a truly independent PPI), I can hardly blame them for not wanting some stranger getting all elbows-deep into the engine they have so meticulously maintained. If there's no "obvious" reason to test compression/LD, how much of a risk would one be running by skipping this test?

I was committed to investing in this extra expense to be sure the car had a "thorough" inspection. But now I am not so sure. I'd love to hear your thoughts on this.

Worse case? A complete engine rebuild; figure easily several thousand dollars to pay someone else to do it.

Not so good case? A valve job; figure easily several thousand dollars to pay someone else to do it though not as much as a complete engine rebuild.

Best case? You get lucky and don't need any repairs.

It's your gamble.

I guess my question is, is this something you would ALWAYS do, whether or not the car showed any sign of engine problem?

Unless YOU are VERY familiar with the car... I would say ALWAYS!

PPI = save money

Non PPI = money pit

I think it'll be more a matter of giving me an idea of WHEN I'll have to put money into the engine...sooner? Or later? it's just a matter of time either way, I'm guessing.

I cannot think of a downside to doing the compression & leakdown. Are there any risks or downsides to it?

[QUOTE=kathycha;4063154]I think it'll be more a matter of giving me an idea of WHEN I'll have to put money into the engine...sooner? Or later? it's just a matter of time either way, I'm guessing."

you have guessed wrong. It is not about WHEN you have to put money in your PO car. One way or another you gonna have to.

The real question is WHO'S MONEY GOING INTO YOUR CAR ?

You bought car, no test, no PPI. You paid top notch $$$ and on the way home or in few days or weeks you filling oil us much as gas.. You repair it, you trowing YOUR $$$ for rapair .

With the test on the same car, you'd know to walk from it or get substantial discount for future repair- and thats SELLERS MONEY in YOUR CAR.

Unless $$$$ is not an issue. In that case I would say buy anything and here you could find bunch of guys who could make a dream car to a slightest detail and specification.

[QUOTE=IDGAF27;4063187] To be clear, DEFINITELY getting a PPI. And I'm happy to get the compression test, too.

Point well taken - if it needs big work ASAP, that obviously would be a reason to negotiate lower price...or walk away...or go for it eyes wide open.

I can't think of a downside to doing the testing. I don't mind spending the $ and had planned to when I set out. I have no interest in breaking down on the long drive home or anytime after if it can be avoided. Knowledge is power.

Just had to say - love your sig line! :D

For anyone still paying attention - the car I'm considering is going in for its PPI tomorrow morning - INCLUDING compression/leakdown testing.

Bottom line:
what's to lose by testing? NOTHING
what's to gain? invaluable information

Being relatively new and not at all schooled in this stuff, it's sometimes hard for me to tell the BS from the SMACKTALK from the truth. Especially when I'm talking to somebody who comes with impeccable credentials & recommendations from here & elsewhere.

But the consensus of those I've consulted seems to be that any mechanic who says he can "tell" whether a car "needs" a leakdown/compression test (when there are no obvious signs) is pretty much...SMACKTALKIN.

All of a sudden things are falling into place. We'll see what tomorrow brings with the inspection and I will report back.

TRYING NOT TO GET TOO EXCITED (AND FAILING)

I hope it meets your expectations, good luck. ;)

flatsix

Now comes the nailbiting! The car will get its once over tomorrow. I will be out of pocket from 8a to 11p tomorrow and will probably have to wait til Friday to get the news. Nails will be down to bloody nubs by then!

Hubby is totally on board now, as he likes the idea of coming with me to Houston & driving a route back around the LA, MS and AL Gulf coasts.

He's 6'4" about 280. I hope he will be comfy in the passenger seat! Any big guys reading this, PLEASE tell me he won't have his knees under his chin!

Thanks for the good wishes. Good luck to you, too!

He'll be fine, I'm 6'2" but slimmer and I fit under the steering wheel, the passenger side is plenty big.


Problem comes when he insists on driving about 10 miles into the trip...I mean, who wouldn't? :)

Naw we won't have a problem with that. He is more into navigating than driving. How lucky am I? We are perfectly matched! But I am still concerned about him being comfortable and we are taking a bit of a risk here. Fingers crossed!

Anybody near Tuscaloosa, Alabama willing to let my husband try on your late 80's 911 sunroof coupe passenger's seat??