hacker-pschorr

Most don't realize what it takes to do a leak-down properly.

1. Remove spark plug in cylinder #1
2. Find TDC for cylinder #1
3. Install flywheel lock tool
4. Install leak-down tool into cylinder #1
5. Pressurize
6. Write down the value
7. Remove leak-down tool
8. Install spark plug
9. Remove flywheel lock
10. Repeat steps 1-9 for each cylinder

This is assuming:
A. Every spark plug boot comes off without a fight and in one piece
B. Every spark plug comes out without a fight and without breaking or stripping

You want a lesson in frustration, do the same thing on a Ferrari 355...

Marine Blue

How much without the end play check (assuming he sticks with buying a 5 Spd)? What else do you include? Not saying it's overpriced if it's thorough but it does help to know what the pros look for.

H2

Afshin,
If I were in the market for another 928, I'd really be interested in your car. I know you care for your rigs. But...selling one of mine to make room for another is a hassle. I once had 4 sports cars at once (two 928s) and my wife asserted some considerable authority (with threats of relieving me of an appendage or two), so I'll have to pass for now. Good luck. I do, however, have a WONDERFUL 968 that I'd consider trading.

H2

Lizard928

Well, I never do install the flywheel lock when doing a leakdown. I normally have a breaker bar with a lot of leverage so that I can move the piston up/down slightly to get an idea of how much of a ridge/wear there is at the upper end of the cylinder. But you need to be paying attention and really have a second person around when doing this.
In other words, maybe best not to try this one at home. At least not at 150PSI

blown 87

Endplay check will add or subtract 160-200 off of it.

For a start download Worfs PPI, but pay no attention to the times he gives, Dave and I have talked about this and the time figures are no where near right.

Then there are other things we look at, and it all takes time.

Marine Blue

Knowing Dave and hearing your comment about spending more time means you're not really performing a PPI. I think you should call this a full 928 cavity search....

But seriously, for someone new to the 928 a thorough PPI is money well spent. Anyone familiar with the 928 should still get a PPI but inspection can be limited to checking things that a normal visual inspection wouldn't find such as leakdown, end play, steering rack leaks, tie rod check, vacuum checks etc.

blown 87

I know one person here who has owned four 928s, and he is a damn good wrench, got bit because he did not do a good inspection, Thrust bearing failure motor, ouch.

I also agree that most cars are not really going to need the whole inspection, most will not make it that far.

I have seen so many great (owners description) that were lucky to go another few thousand miles with out major problems or fire.

Landseer

I'd ratchet scrutiny with spend.

For some of these I've bought, a quick visual to ensure a parts-sell tally is close to the spend --- that's enough.

blown 87

How many of those were 25 grand cars?

You guys know I would rather buy one with good paint and interior and then redo the mechanical stuff so I know it will not let me down, shiny does not get ya home.

blown 87

And many want a hot AND cold leakdown.

I think it is kind of crazy, and have told the people that, if a 928 runs well, idles smooth, chances are the compression is good.
There are bigger fish to fry with their money.

danglerb

Purpose of a PPI; Skip or buy, negotiate price, and get a baseline for later scheduled PM and other work.

The first half hour to an hour should find most of the things that would kill the deal. Visual inspection, drive the car, put it on a lift, and if its not a go, then stop.

Next couple hours are checking things in depth to give an idea of what I need to spend now, and a rough guess on the next year or so PM schedule. Thickness of brake pads, compression, and follow up a bit on any issues the first part of the inspection turn up like leaks etc.

These are 15 to 30 year old cars, and I think its more important to find the right car that suits your tastes and desires than it is to quibble over price or condition too much.

hacker-pschorr

To do a proper hot leakdown you must fire up the engine between cylinders to maintain a consistent temperature....

If you ever think "we" are going overboard with the 928, take a peak over the fence:
https://rennlist.com/forums/928-foru...-original.html

blown 87

yep

soupcan

My last PPI consisted of only one question...Does it have a tow eye to put it on the trailer? Yup...Deal!

danglerb

The higher the sales price, the more likely you REALLY need a PPI and thorough records check.

If a car is cheap enough you can part it for big profit, no PPI needed, just verify what it is.