help with PPI leak-down numbers

bkreigsr · 04:35 AM

I have been looking for a 911 for/with my son and we found a 81 SC with the following leak-down numbers from the PO PPI in 2004:
#1 - 20%: #2 - 8%: #3 - 9%: #4 - 9%: #5 - 10%: #6 - 9%
These numbers, especially #1, are out of my comfort zone and I'm trying to get an affirmation from the consensus of Pelican experts.

Should I run and hide, or is there the possibility that the car can still provide 5-10,000 more miles before a rebuild? It's going to be driven approx 2-3,000 miles/yr with 2-3 DEs/yr and an occasional autox.
thanks
Bill K

jsmithcds · 04:45 AM

how much for the car?
how many miles?
any mods?

A ppi 5 years ago with 20% in a cylinder would scare me........

imcarthur · imcarthur's Garage

Quote:

Originally Posted by bkreigsr

with the following leak-down numbers from the PO PPI in 2004

2004? From the PO?

Time for a new test from an independent source.

Ian

tonythetarga · 05-19-2009, 04:57 AM

Five years is too long for those numbers to have any validity. That #1 is not a good number but it could also be an incorrect reading. Either way, you have some good shops in NJ and you might want to get a RX for a shop near you (or the car). Do your own PPI and get your own results.

jsmithcds · 05-19-2009, 05:04 AM

for $15k with 134,000 miles it must be immaculate besides the motor if you are considering it?

bkreigsr · 05-19-2009, 05:09 AM

if you must know, the only cars we have been considering are immaculate ones.

Physedfailure · 05-19-2009, 05:25 AM

Quote:

Originally Posted by tonythetarga

five years is too long for those numbers to have any validity. That #1 is not a good number but it could also be an incorrect reading. Either way, you have some good shops in nj and you might want to get a rx for a shop near you (or the car). Do your own ppi and get your own results.

+1

PCA7GGR · 05-19-2009, 06:25 AM

Let us know what the "current" leakdown numbers turn out to be.

You might also check into how much a topend job goes for now days.

Steve@Rennsport · 05-19-2009, 06:42 AM

Quote:

Originally Posted by bkreigsr

I have been looking for a 911 for/with my son and we found a 81 SC with the following leak-down numbers from the PO PPI in 2004:
#1 - 20%: #2 - 8%: #3 - 9%: #4 - 9%: #5 - 10%: #6 - 9%
These numbers, especially #1, are out of my comfort zone and I'm trying to get an affirmation from the consensus of Pelican experts.

Should I run and hide, or is there the possibility that the car can still provide 5-10,000 more miles before a rebuild? It's going to be driven approx 2-3,000 miles/yr with 2-3 DEs/yr and an occasional autox.
thanks
Bill K

Bill,

Any leakdown tests that don't tell you WHERE the observed leakage comes from is pretty well useless as thats the single biggest value of such diagnostics.

In your example, that 20% leakdown may simply be carbon under the valve which would be nothing to fear vs a ring or piston problem that would be expensive to repair.

I'd kindly suggest that any shop performing a PPI on a potential candidate who takes the time to do that mandatory leakdown, tells you where any air was escaping from. This allows you to make a much more accurate assessment of engine condition and potential repair costs, both of which are bargaining points.

bkreigsr · 05-19-2009, 07:16 AM

agreed
thanks Steve, thanks Tony for taking the time to respond.
Bill K

bkreigsr · 05-21-2009, 12:12 PM

Better news today.
Tony, you were right, we had another shop do a leak-down and here's what they found: #1- 3%, #2 - 2%, #3 - 1%, #4 - 2%, #5 - 5%, #6 - 3%.
We will post pics of the car when the deal is done.
It's a beauty and real nice starting place for my son to get an the air-cooled experience.
thanks for your advice and responses.
Bill K