Leakdown nightmare

I'm selling the 2.2 liter engine that used to power my 911, and I just had a leakdown test performed by my mechanic. The results were really surprising. It tested great in all cylinders except the last one in the firing order. #5 tested with 92% leakage (or whatever the correct term is).

My question is: is this possible? The engine ran great prior to being removed from the car, tested (with a g-tech pro) at 130 hp at the wheels, and did 0-60 in 7.4 seconds. These are better-than-stock results. If the #5 cylinder is as bad as this test seems to be saying, could the car have run as well as that?

For those of you with a good ear, a fast modem (or cable connestion, as the file is 8 megs), here's a link to video of the engine from the day before it was removed. Is it possible that this engine is essentially operating on 5 cylinders?

http://24.130.89.162/Engine.mov

And here's an audio-only WAV file from the same thing, which is smaller (only 400K):

http://members.rennlist.com/jackolsen/EngineSound.wav


Any input on this would be appreciated. Otherwise, I just saw a very valuable engine become one that's worth a heck of a lot less.

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Jack Olsen
1973 911 T sunroof coupe
http://members.rennlist.com/jackolsen/Jalopy.html

[This message has been edited by JackOlsen (edited 08-29-2000).]

Although I did not listen to it. It is possible to have allot of blow by at the rings in a static test but the dynamic power test at "rotating speed" seems different and the weaker cylinder not as evident.

With the piston moving really fast sweeping the cyl. (the oil creating a better seal then at static) it will not be as noticable. It would not be as evident as pulling a plug wire. Although, it would almost be as easy to find a suspected weak cyl. if you get a digital tach and while idling pull one plug wire at a time and see how much the tach drops in between the each pull (reconnect it each time). The more the tach drops the stronger the cyl. If the RPM does not drop much then the cyl is weaker then the rest because it did not make much difference it was there or not.

s

Just a thought. Also be careful if you do this (most should stop the engine between pulls or get shocked ...that's bad. Do not go above idle either.... that could be bad too).

[This message has been edited by H20911 (edited 08-29-2000).]

Jack,

Sorry about the scare, whether it turns out to be a real nightmare or not.

Do you have any compression numbers to go along with the leakdown test? The reason I ask is that I have never needed or used leakdown tests, AND, Bruce Anderson doesn't use them or swear by them either ... they are subject to measurement errors, and I feel many shops use them to push customers into unnecessary work on otherwise usable, healthy engines. I'm not saying that is the case with your mechanic, but it does happen.

If your compression test numbers are all good, and no weak cylinders are found with the sparkplug wire test suggested above, I can't really see why that engine should be condemned! And, I don't think your car's 0-60 time sounds like a five-cylinder 911, either!

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Warren Hall
1973 911S Targa

Thanks, guys. 'Nightmare' is certainly too strong a word, since it's only about how much I sell this engine for.

Unfortunately, I can't do a compression or a spark plug test because the engine has been pulled. The only apparent option, as far as my limited experience goes, is to have the engine trucked to another mechanic, for another leakdown test. This will cost more money, naturally.

If the cylinder or ring is bad, then that's that, and the engine is worth less. If the consensus is that the engine couldn't perform as it did with one cylinder leaking 92%, then I'll probably opt to spend the extra money.

But again, I'm new to this. Any advice at all is appreciated.

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Jack Olsen
1973 911 T sunroof coupe
http://members.rennlist.com/jackolsen/Jalopy.html



[This message has been edited by JackOlsen (edited 08-29-2000).]

Couple things come to mind here:

If the leakdown is that bad, you should be able to hear it, either at a port (int or exh) or at the crankcase vent.

If it's at a port, it may be a piece of carbon stuck between the seat and valve.

It is possible to clear this but it's too crude for me to write publicly(works though).

I have had this happen. I've heard it is fairly common with older motors. Usually happens or is found during valve adj. A piece will fall off then the plugs are removed. A very loose clearance and a bogus reading result. When it clears, the gap is too tight, causing all sorts of problems.

If it's at the cc vent, well...
JPIII

What's the possibility of dirt on a valve seat on an engine that has been sitting? Can't you bolt on a starter and hook up some cables and do a standard compression test without the warm up? Have you checked the valve clearances? Could indicate source of problem.

Dan Smith

The end of the story involved using a goose-necked optic thing to look into the cylinder, which revealed a groove cut into the cylinder wall. Some kind of trouble, obviously.

I'm still surprised by how strong the engine ran, and tested. Live and learn.

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Jack Olsen
1973 911 T sunroof coupe

Whoops. Double post.

[This message has been edited by JackOlsen (edited 09-09-2000).]

I had a 2.7 the had jumped time on the right bank-Maybe one or two teeth on the chain per say, but that sucker ran entirely off the left bank!!! AND, you could rev it, and it would idle. 2 cylinders with 5-10 pounds, and one with absolutely nothing.
SC