Correlations with SAI/Valve Guide issues ...
#17
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"I hope you don't mind me posting your write-up. Just part of the "information passing" game. Knowledge is power!
Dave"
No, that's find. That's why I wrote it, i.e. to be helpful to 993 owners.
Dave"
No, that's find. That's why I wrote it, i.e. to be helpful to 993 owners.
#18
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I have a 98 C4 Cab, original owner, and just turned 40k. No CEL light yet. If I thought that a CEL light was a significant possibility in the near future I think I would sell the car -- I drive it less than 3,000 miles a year now and don't enjoy it enough to tolerate the idea of spending more than $5,000 to overhaul the engine.
I would be greatly interested in a poll to give me an idea of my chances of experiencing this problem. I live in San Diego so no problems with the car having to warm up from cold temps. I have been using the lighter weight oil as recommended by Porsche -- should I change to 20/50? I drive the car aggressively, meaning I frequently rev it to 4-5,000 before shifting, and my driving is a mix of short and long trips.
I polled people on the board a couple of years ago and as I recall almost no one who had accumulated over 50k on their car had escaped the dreaded CEL light -- maybe one or two out of ten. Not good odds. It seems like the people who own 98 model years haven't had this problem but maybe that's just because there's hardly any of us around....
My .02
Mark
I would be greatly interested in a poll to give me an idea of my chances of experiencing this problem. I live in San Diego so no problems with the car having to warm up from cold temps. I have been using the lighter weight oil as recommended by Porsche -- should I change to 20/50? I drive the car aggressively, meaning I frequently rev it to 4-5,000 before shifting, and my driving is a mix of short and long trips.
I polled people on the board a couple of years ago and as I recall almost no one who had accumulated over 50k on their car had escaped the dreaded CEL light -- maybe one or two out of ten. Not good odds. It seems like the people who own 98 model years haven't had this problem but maybe that's just because there's hardly any of us around....
My .02
Mark
#19
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quote: "It seems like the people who own 98 model years haven't had this problem but maybe that's just because there's hardly any of us around...."
Or more likely because most of you don't have enough miles/time yet.
My '96 started CEL'ing with less than 30k miles due to SAI ports (sadly, I found this out well after the fact). Have your regular oil changes included replacement of the exhaust check valve? It's somewhat of a consensus that this check valve failing is a big contributor to the carbon build-up in the SAI ports. Are you burning oil? As you know, an indicator of worn valve guides, which also contribute.
There's no easy answer, my friend... certainly easier to sell before you'd feel compelled to disclose the problem, but who knows, maybe you'll get 75k miles outta yours!!
Good luck...
Or more likely because most of you don't have enough miles/time yet.
My '96 started CEL'ing with less than 30k miles due to SAI ports (sadly, I found this out well after the fact). Have your regular oil changes included replacement of the exhaust check valve? It's somewhat of a consensus that this check valve failing is a big contributor to the carbon build-up in the SAI ports. Are you burning oil? As you know, an indicator of worn valve guides, which also contribute.
There's no easy answer, my friend... certainly easier to sell before you'd feel compelled to disclose the problem, but who knows, maybe you'll get 75k miles outta yours!!
Good luck...
#20
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Originally Posted by trojanman
quote: Have your regular oil changes included replacement of the exhaust check valve? It's somewhat of a consensus that this check valve failing is a big contributor to the carbon build-up in the SAI ports. Are you burning oil? As you know, an indicator of worn valve guides, which also contribute....
#21
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Originally Posted by Ray Calvo
Don't drive it daily to & from work.....
Bottom line, don't be afraid to drive your beauties - they can handle it!
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#22
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quote: "Hi Trojanman, Is this the check valve you are referring to? What would be a reasonable cost to have a wrench replace the part? I don't think I can fabricate the special tool I need to do the job myself. Thank you."
Hey Jason... yep, that's the one. There are others here much more qualified than I regarding the difficulty (or not) of the R&R of this part... what I do know (and have seen personally) is that they get crudded up pretty easily and many times break in half during removal. I don't think it's cost-prohibitive to have it done and it's been recommended to me to do it every 10k miles or so (or every oil change).
Hey Jason... yep, that's the one. There are others here much more qualified than I regarding the difficulty (or not) of the R&R of this part... what I do know (and have seen personally) is that they get crudded up pretty easily and many times break in half during removal. I don't think it's cost-prohibitive to have it done and it's been recommended to me to do it every 10k miles or so (or every oil change).
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This valve is something I would recommend replacing as a preventive measure. Even low mileage cars have shown these to be rusted. Maybe every 30K miles?
Its not too difficult to change in situ. Just need the Z-bent wrench as illustrated on p-car.com. I posted a few pics of the SAI valve wrench I made. Feel free to PM me and I can send more pics..
Its not too difficult to change in situ. Just need the Z-bent wrench as illustrated on p-car.com. I posted a few pics of the SAI valve wrench I made. Feel free to PM me and I can send more pics..
#24
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Originally Posted by chris walrod
I posted a few pics of the SAI valve wrench I made.
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#25
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I have not ever changed this valve.
Quick question, is this valve something that rusts from exposure to rain/water on the engine? If so, could that be why people living in very arid areas don't seem to get the CEL light? I seem to recall someone from Phoenix saying they knew of no one in their area getting the CEL light despite very high milage cars and very high ambient temperatures.
Mark
Quick question, is this valve something that rusts from exposure to rain/water on the engine? If so, could that be why people living in very arid areas don't seem to get the CEL light? I seem to recall someone from Phoenix saying they knew of no one in their area getting the CEL light despite very high milage cars and very high ambient temperatures.
Mark
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My 97 993 has 61900 miles and so far no CEL. I live in the high desert so we do get some heat here. I drive the car almost daily and I drive it like it was meant to be driven.