Randy M

When I had the PPI done on my car I had a compression test performed w/ it. Here's where they came out:
155 160 160 165 160 165
Tech said that you want all of the cylinders to be close. What do you guys think of these numbers?

P.S. Recently I've been hesitant to ask any questions at all because someone will tell me to use the search or "this question has been asked meeelions of times" Whats up with that? I'm beginning to think that some rennlisters are crotchedy old farts that forgot to pick up their viagra prescription.

993chaz

I agree, half the fun is interacting with others. You can't get a personal email from an archive.

DKP 97 C2 Coupe

I would say that those numbers are well within the "acceptable range" of a compression test. I've always thought that the test was really a general test to ensure that nothing significant was wrong with the motor; a "delta P" of 10 psi is fine. IMHO reading anything more into these numbers is not warranted given the accuracy (or lack thereof) of the test itself.

In regards to your "P.S.": I am a relatively new Rennlist member (as you can see). I have enjoyed going back to about 18 months ago and reading my way back to the present day. One of my impressions of the 993 board is that there are a number of "hard-core" guys that not only interact with the board virtually every day but also may even know each other personally. They have a very keen understanding of the "hot topics" of the 993 world and have been there and done that. As such, they perhaps aren't always very interested in extending a hand to someone who may be new to the board or the 993. I'm not making excuses for them but it just seems like that's the way it is. Me, on the other hand, greatly value and enjoy the 993 board but may only log-on once a week. I guess it's a double-edged sword; the "old-timers" have a wealth of experience and knowledge dealing with the 993 and I respect that in spite of what at times may seem to be a condenscending attitude to others who may not be as "in-the-loop" as they are. I think the up-side far outweighs the down-side in this instance.

Cheers, David

Randy M

What is the 'acceptable range'?
I agree with what you stated about my P.S. too. There's alot of guys here that have a great deal of knowledge of 993's and Porsche in general. Sometimes they tire of the same questions. I can understand that.

DKP 97 C2 Coupe

I don't have my reference materials in my office (in the process of moving) but I'm sure that Bruce Anderson has numbers that he feels are "acceptable" in his book. Perhaps someone else on the board can reference it for you. I will say that I would not have any trouble or concerns with my car having a "delta P" of 10 psi. The parts of the motor that are involved with the compression and burning of the fuel-air mixture are in fine shape with test results like you have. David

Craig W.

Gary,

Use search. Search is good. Search is your friend. Feel the search. Become the search.

BE THE SEARCH!

Randy M

RRRRIIIGGHHHTTT (Dr. Evil voice)

E. J. - 993 Alumni

Here are some thoughts from a Crotchety Old Rennlist Fart (can't believe at 31 I am calling myself that). These are not meant to be disparaging at all, so please don't take them that way.

Part of the problem is messages just like the one you posted. Not only do we get tired of the same questions over and over, but also the comments just like your PS (not BS). It just gets old. The search function is very powerful. I realize that questions must also be asked on the forums as the archives are certainly not complete, just don't expect the old farts to continuously answer them over and over again. Secondly, recently there has been a spate of questions on the board and via email to the old guard, most of which are answered quickly yet we never hear a 'thanx' or an 'appreciate it'. It certainly doesnt hurt our feelings, nor is it truly expected, it might just be nice to hear every once in a while. That's all. If you don't know what TIA means or stands for, you weren't here a while ago when almost every question was prefaced with those simple three letters.

Now as for your question and my real purpose of posting, you can't possibly tell me you tried to search for your answer (and nowhere in your post do you actually say you did).

I am going to walk each and every person here through the 3 minutes it took me to find an answer to your question.

1. Click on search button.



2. Type "Compression Test" in the first available box:



3. Press Search (see above picture)

4. Look at your results:



Personally, the 17 results are probably not that hard to sort through, but I got lucky and knew I needed 'results', so I took the obvious answer and clicked on the one that had the word 'results' in the title: "PPI Results - Leakdown interpretation needed".<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=3&t=005317" target="_blank">Here</a> is the thread.

Guess what I found smack in the middle of that short 11 message thread? This little gem by one of our old farts:

[quote]By: Steve Weiner
<strong>Now,.....the leakdown figures you posted look good to me as this indicates good valve & ring sealing. I would be inclined to perform a hot compression test, and simply make sure that each cylinder's pressure is within 15 psi of each other.</strong><hr></blockquote>

Literally took me three minutes to find the exact results you were looking for. 15 psi variation.

Take this for what it is, proof positive that the system works. If people want to post questions, certainly I don't have a problem with it, nor do any of the old timers, just don't expect us to answer each and every question time and time again when the search works as well as it does.

Now go out and have fun. I know I'm having a blast driving the 993 with snow tires in todays ice storm.

E. J.

Luis A.

FWIW, I had a leakdown test performed last week on a C2S I was considering (didn't buy it) and the numbers were 1-2% in most cylinders with one having 0%!. The car had 35k miles and it was a '97.

Luis

maurice97C2S

Had a quick look in Anderson - "healthy engine should be 130-170 psi, all cylinders within 15% of each other" This not model-specific, 993 should obviously be on the hi side. Same advice really for any engine.

Relax ! Cheers, Maurice

Randy M

E.J. I understand. (whipped dog going back to his doghouse) By the way I'm 32 and my comment was not to be taken literally. Sheesh

chris walrod

when I had my 1995 PPI'd, all holes were VERY even at 185 psi. I asked about all readings being very close if not spot on to each other. He said they find that to be the case in most 993's.

YMMV

Chris

Randy M

Thanks Maurice for that. And thank you to everyone else who has ever attempted to answer any of the questions I've ever posted during the 2+ months of frequenting this site.

Mr Michael B

EJ. Man... That was well done.

Luis A... Leakdown is one thing... Compression test is another. Do a search to find out specifics <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" /> - Good info though. Glad you posted it. Someday in the future someone will need to know good leak #'s and the search will lead them to your post.

E. J. - 993 Alumni

It wasn't, sheesh

BTW, how do you have an M030 suspension with PSS9 Coilovers? You got 8 wheels on that Porsche?

E. J.