cold cylinder leakdown numbers

[JFairman]

I just did a cold leakdown test on my '87 930. I don't have a turbo at the moment so there's no way to start it right now.
I used a $29 Harbor Freight leakdown tester so no telling how accurate that is.
This is what it looks like.

The instructions seemed to leave out one step so it was kind of confusing at first but i think i figured it out.
With the unit connected to an air compressor you turn the regulator to the right until the right hand gauge is at zero. That is all the way to the right or about 5 o clock.
When you are there the left gauge is at about 15psi, while the compressor was at about 60psi.
Then I connected the brass air hose connector on the hose from the unit to the other short hose in the kit that I had already screwed hand tight into the spark plug hole of the cylinder @ TDC to be tested.
Then the right hand gauge drops down counterclockwise a little in percentage.

Here is what I got on my cold motor:
1-23%
6-20%
2-22%
4-20%
3-23%
5-20%

It is not easy zeroing the cheap regulator on this unit but I think I got it pretty close.
Does this seem about right for a cold leakdown?
At least they are pretty consistant.

thanks in advance.

[john walker's workshop]

you don't do cold leakdowns. period.

[cgarr]

What orifice does it have? Both gauges should be in PSI, if the pressure in is 80 lbs then you should read the second gauge at 75 lbs or so, but that all depends if you have the correct orifice for the size bore you are checking.

[my1st911]

I'm looking at the same guage on ebay. Wanted something that wouldnt break the bank for me, and find out how my 2.7 is doing. Anyone recommend it, or another type that wont set me back 200 from strap-on. I know I have issues with my baby, but I dont want to spend more for a guage then a used 2.7 to throw in my car

[dad911]

Doesn't seem right. Each cylinder at TDC when tested? Could you hear air coming out intake, exhaust, or breather?

[JFairman]

Each cylinder was at TDC.
I also pressurized each cylinder straight from the compressor at 110psi and listened through a hose to my ear at the throttle body, exhaust header where the turbo would have bolted on, and in the oil filler cap to the oil tank.

I could either hear nothing or the very faintest hiss of air leaking. Some air has to leak and the motor was cold. I can not start it right now to get it hot minus the turbo.

thanks.

[cgarr]

Well there ya go, poor mans leakdown test, works for me!

[trekkor]

I'll be getting one of those. Thanks.


KT

[jcunning]

I bought that same leak down tester. The directions are printed wrong for starters. Second, I'm not sure how accurate those two gauges are.

Because of the mis-printed directions, I busted my second (leakage) gauge right off the bat. From there on I could only get about 10psi on the left gauge before the right gauge pegged.

I simply pulled off the right gauge and put on a better quality one with numbers and now I can set it the left gauge to 50 psi or 100 psi and both gauges read the same scale.

Then when you plug it into the cylinder, the right drops down as air leaks out and you get your reading.