csertich

Thanks for the clarification Tom. I appreciate the info...
chuck

max911

i was at a used Porsche car lot of rather 'mediocre' repute a few days ago snooping around. they had an intermeccanica speedster and a few 993 cabs in their mostly Porsche inventory. they have a mechanics bay where they work on the cars they are putting up for sale, and on other's Porsches as well.
We talked about the blocked air-passage problem. The fellow, who i assumed was an owner or part owner, said that they have cleared the passages using a solvent soak. He said it takes 10 days. He also noted that it is almost always the number 1 and 3 cylinders that are the worst. (hope i remembered the correct numbers)
i did not pry into the exact procedure, or what solvent was used to dissolve the deposits. ( i fgot the feeling he was not going to divulge too much).
He said he had done several, and there was a fellow from Nevada bringing in his car for the "soak".
I also did not ask him what the cost was, or what the guarrantee was that it would work.
After rereading my post, I can tell that i would not make a very good reporter!! more questions unanswered than answered.
If anyone wants the name of the dealer, send me a PM.
I am not affiliated, related, reimbursed; nor responsible for good pieces removed from your car during the ten day duration
max

Randall G.

I found it interesting that Excellence Magazine's 993 buyer's guide focused on the (expensive) CEL being caused by leaking valve seals, as opposed to being caused by clogged up secondary air injection ports. Based on what I've read on this board, the high $$ check-engine light repair has primarily been an issue of plugged SAI passages (that does require expensive head work to repair using the "conventional" approach). While I have read a little of premature valve guide wear, can't remember reading much (any?) of leaking valve seals being a source of the CEL. Am I missing something?

911

My neighbor, unfortunately, just had the CE light come on last week and his car is in the shop ($6k). His car is a '97 C4S w/ about 45,000 miles.

max911

Randall, my interpretation of the excellence article is that it is based on Porsche's "explanation" of the problem. it is this line from Porsche (wear and tear...worn guides excuse) that they are using to skirt the emission equipment warranty claims.
i am curious as to how many of the cars with the blocked passages actually have the valve guides worn out of spec!!
max

Randall G.

Guess I should have (re)read the whole thing before making my last post. Later in the article, the author makes a connection between the CEL, SAI and worn valve seals:





Still....my understanding to date is that the valve seals and SAI passages being clogged are not related. That is, SAI passages are getting clogged, regardless of valve seal condition. Guess this explains why dealers want to replace the valves as a "fix" for the SAI light--they're taking the same position as this article does (as Max suggests).

I think the conventional wisdom of this board is if you can get rid of the SAI light in order to pass emissions, your car will run fine, no harm in performance, oil use, etc. This wouldn't be the case if your valve guides are worn.

David '96 993

Max is correct in his comment that the valve guide wear is the standard dealer answer. When one local dealer said that was my problem, I mentioned that my car only burns a quart of oil every 2500-3000 miles. Note that my miles often include track miles...so there goes the PCNA theory...Valve guide, schmalve guide. It is a blocked passage issue.

There are cars out there though that do need to have valve guides replaced whether they have an SAI issue or not. Just note how much oil you burn. I believe it is recommended if you burn one quart in <1200 miles.

tom_993

I was just checking out the web page for GIAC ( www.GIACusa.com ) . They are the people who make the chips that Steve W and others sell for our cars. Under the “capabilities” section, I found the following listed:

“Adding/Removing OBDII Sensor Functions”

(Go to this page ( http://www.giacusa.com/giac/home.php?car=por# ) and click on “Capabilities”)

You know where I’m going with this: Have them make a chip that removes the guilty sensor function. I’m sure there would be a market for this. While my ’95 appears immune, I’m sure most of you would rather replace your chip (even at the high cost for a ’96) than tear your engine apart.

Tom
’95 993

Jeff

Kevin is right on the money -- this issue is wide spread, enough so it has hit one of the most popular publications. The guy who writes the buyers guide for the same magazine has mentioned it more than once. This is a design flaw -- Porsche needs to get involved and at least tell us what the answer is -- I've spent too much $$ on this just trying to find the fix. The stupid CE light just went back on -- I'm fast approaching the same boat as 993 MSJ

Steve Weiner-Rennsport Systems

Hi Tom:

Your idea about runing the air pump continously might do a dandy job of keeping the port from clogging, but I think the cats will overtemp and burn out fairly quickly.

dawger86

For what it is worth, I just purchased a '97 C2 w/ 36k miles and experienced the same fault code. The check engine light illuminated after I took delivery of the car, but before I was able to register it. The car was not able to pass inspection due to the fault code, and I was instructed to take the car to a shop for diagnosis. The technician informed me that the problem was being caused by loose valve guides, which in turn ruined the valve seal, and burnt oil caused the blockage of the air circuits. The estimated repairs to correct the problem totalled roughly $8000. Pretty deflating experience after being on such a high after picking up the car...

I have the car at a Porsche dealership right now and am hoping that Porche NA will cover at least a portion of the repairs under goodwill. However, I am not optimistic since I am not the original owner and only sporadic maintenance records exist for the car. I'll follow up with results.

Lenman

Hello, I"m not even an owner yet but I'm currently close to being. I called the local Porsche shop, Schnieder Autohaus here in Santa Barbara. Joe S I believe heads the local PCA chapter and is the most respected P guy around here. I asked him about the problem and he says although he's heard of it he's never seen it. Obviously it exists, as many people are dealing w it, but one thing he said was that since here in SB they don't check for NOS on smog checks, it won't be a problem passing. Doesn't mean it doesn't exist, just doesn't show up on the test here. 30 miles south in ventura county they do check for NOS emission during smog. I say this because maybe those of you in CA, like Kevin above, may want to come here for your smog to be done. Others I've talked to said it's not an issue as far as driving the car, just the hassle of the engine light coming on and having to have the reset done after the engine light comes on. Is that the extent of the problem, screwing up our smog passing, or does it manifest itself in lesser performance? If it's only the smog issue and my locale get's around it, it doesn't bother me. IF it effects performance, than I"m bothered wether it passes smog or not, because than I'd have to deal w it. Just throwing out what LITTLE I know from talking to others. Take care Len

Don't lift

Good timing, I've just purchased a '97 C2S with 57K miles and it wouldn't past CA smog the first time. Searched this forum and followed the complicated procedure of the two runs of (20-28 minutes runs of cold start with air cond. and rear defl, 3 min. of 55mph, back off to 20mph...........etc.) to reset the ECU to "readiness" mode. Took the car in the next day, it passed! For those in CA and don't want to perform these runs to reset the ECU, just go to the referee station and they will pass you 'cause they know of this problem!
Yesterday the damn CEL came on and stayed.........By the way anyone in the L.A. area has the software to read the OBDII code out there? I might ask for a favor to plug me in....(pls. PM me) If the code reads is the SAI blockage, this is my take...... according to my research it does not impair any performance and NO, NO, NO! I won't open my engine for that!
1) I will give MOTORVAC a try (anyone with any experience please post)
2) My mechanic saids the soaking with something also should work.
3) If nothing works I will buy the software and reset the CEL every time
and when smog comes, I will take it to the referee station.
The only thing I wanted to be sure is WITHOUT CLEARING THE SAI
a) Will it affect any performance now or later?
b) Will it get worst with more miles?
c) Will it cause more problems or damages later?
(Steve W. or anyone with more knowledge please post)
Regardless of these idiosyncrasies on these machines, they are still the BEST overall sportscar money can buy!

Jeff

I'm willing to support gathering the necessary data either monetarily or with my time. Porsche needs to take notice and give us a hand. They could at least tell us what the real fix is so we don't spend $$ on our mechanics rooting around with wires, caps, filters etc.
One last point, Porsche has done very well recently with quality -- in fact they're at the top of the JD Powers list. However, our 993's were built before Porsche got their quality act together -- I understand they now rely on off shoot of the Toyota Production System and that has had a dramatic impact on their build quality. We have the best looking Porsche with the most problems.

stedge

Jeff:

Very kind of you to offer that kind of support!

Re: the best looking, etc, I am not yet an expert, but my sense is that for 6-8 year old cars, many of which were either babied or driven fairly roughtly, they are holding together beautifully. There are some issues that have arisen, absolutely, but if they were less expensive to fix, they would not be issues. I see the cost as the issue, not the number of reported problems.

I have had Hondas, Mazdas, Nissans, and Subarus, experience with Lexus, Saab, VWs, etc. Not a single one of them was perfect. They were cheaper to fix when a problem occurred, however. That is about the only difference.