Paulsha911

CEL came on a month ago with SAI code. Reset it, and it came back on within two weeks.

Brought it to Devek and had Ross looked into it. The obvious stuff were working fine, including the SAI valve, etc. He took off the valve cover and did the wiggle test. A couple of valves had a lot of side-to-side play.

My car has 52K miles. When I bought it, I was psychologically and budgetly prepared for such an event although I didn't expect so soon. Anyhow, I was given the quote of $5K and I have given them the green light.

Are there anything I should watch out for? I do not plan to track this car - I tracked the heck out of my previous 996s but just don't have the heart to do it to my beloved C4S... It's strange... Anyway, if I don't track my car and I am looking to maximize reliability of the engine, are there any obvious upgrades I should ask Devek to do?

Thanks in advance.

epj993

I'm not sure that the wiggle test is the best way to check for worn guides or a top end rebuild. Was a leak down or compression test performed? What's your oil consumption?

trojanman

From what I understand, a seasoned mechanic can learn much more from a "wiggle test" than a leakdown... I believe there's a spec for the allowable play of the valves inside the guides, and if you're significantly over (I was) you are due for a valve job.

It goes without saying that the guides should be replaced with non-OEM ones, and you likely should have your six exhaust valves replaced as well (mine were very pitted). Intake guides and valves were fine, by the way.

It's painful Paul, but you're going to feel so much better about your car once it's all done... no more fear of your CEL. Looks like you've already got the LWF, so no sense in doing a clutch.

Good luck.

Paulsha911

Would a leak down test give any additional info, now that the CEL has came on a couple of times and the valves seems to have a lot of side play? I can ask Ross to do one if that helps. But it costs another couple hundred bucks, right?

Regarding oil consumption, I did not measure it religiously. Rought estimate is that it burns a quart every 1000 miles or so. (The meter went from 3/4 to red in about 400-500 miles. And it seems to take roughly half a quart to bring it back up to 3/4.)

I only had the car for a couple thousand miles so I hasn't quite started logging these stuff yet....

No3

Paulsha911

That's my sentiment exactly. I already prepared for the worst before I bought the car. People told me that PPI is no guarantee that there is no SAI issues. Anyway, now I just want to get it over with, and I hope to drive the car forever. Unlike the 996s I had, I feel like I CAN stay in love with this car for a long long time. Plus, even if I sell it, I wouldn't want to hide the issue... This is such a small community and I value my integrity more...

Regarding the wiggle test, Ross actually showed me the tech manual and how much play there should be. Tow of the valves are way beyond the specs. One actually "stucked" and won't move back to center without some slight help.

gordo993

When my valve guides replaced, my compression was fine - when the exhaust valve in question was closed, it seated like it should. When that valve opened, it was folpping all over the place. It degraded quickly - by the time I got it to the shop, it was making quite a bit of noise. Luckily, that valve was not damaged and did not have to be replaced. All of my exhaust guides were in bad shape, and were all replaced.

Terry Adams

My car runs like a dream since I had the top end done at Devek. Oil use is (to me) a phenomenal 1 qt per 6K miles. I could not resist the LWF/RS Clutch "while we are in there". The only additional thing I got was a new set of plug wires.

Steve Nagata

I just completed a full rebuild (While you're in there things also)

Ended up going with Bronze Manganese guides. I was told bronze phosperous guides are good too. Don't go with stock crap. The valve guide problem will return eventually.

My mechanic also did the wiggle test. Valves had .3mm of play.

AnthemAVM

Sorry to hear this, that is why I prefer the 95 993.

Michael

ceboyd

huh? how would the 95 be any different in when it starts to leak oil and need a top end rebuild?

trojanman

You're missing the point, Michael... the only difference between the '95 and '96+ is the fact that the '95 won't throw a CEL for clogged SAI ports. A '95 is just as likely to have worn guides as any other year.

delanobe

All 993's suffer with this problem 94 till 98! One thing you really don't want is a valve that breaks because of the worn guides.

Regards

delanobe

Does somebody know what the break in period is after a full engine rebuild? ( valves, guides, cilinders, crank shaft etc...?

Thanks

Rick Lee

$5k for a top end is a pretty good deal. It cost me $4500 to DIY it on my SC, though that was with some good upgrades. My break-in period was 1000 miles and that included three oil changes and a valve adjustment. I guess it's a little easier on a 993, since there's no valve adj. Not sure I'd spend the money on Mobil 1 for break-in duty.

2ndof2

"Stickem Up!!!" (hijak)
So how exactly does one decide to do a top-end rebuild or not if oil consumption is within specs but the "wiggle test" suggests valve guide wear? The error codes for SAI on my car shows one bank is clogged and registration with smog cert required is due in a few weeks for me. Clutch is doing fine and everything is running well....any reason why should I (or anyone else) should pay $5K+ at this point? I think not!