Tippy

I have a 996 now but was considering the 993 as my next car. Just had a quick question regarding valve guides. I know some people dont want to hear about this topic just as us 996 guys hate to hear about catostrophic engine failures and RMS leaks. My question goes, if I find a car that has had the valve guides replaced, am I going to be confident that it is fixed for good, or meaning did the replacement guides cure the problem? Thanks Tippy

Father of 3

I don't think you'll ever know 100%. That being said, the main thing you will want to know is what type of valve guide did the PO use when the rebuid was done. Search and you will see that most support using non-OEM valve guides as a replacement because they are too soft. Steve Weiner sells a phosphorous bronze valve guide that some have used here. I'm sure there are other formulations as well. The key is, which shop did they use and what materials did they use as replacement.

Steve Weiner-Rennsport Systems

Hi Cory:

Replacing the factory guides with aftermarket ones, provided they properly installed and fitted, along with enlarging the SAI passages in the heads, really helps this problem from recurring.

You'll not revisit this issue for a VERY long time.

SR71BLACKBIRD

Corry I don't think anyone should be sorry about asking any questions like these and for asking and I really get annoyed when people try to shut people up when newbies or anyone are asking valid questions on problems that they have heard rumors about. I don't find this to be a problem much on the 993 forums but on the 996 forum on catastrophic engine failure you're dead meat if you talk about it.

I don't have Valve guide problems on my 43,000 mile 95C2 yet as I use about 1 quart every 2000 miles but I am sure one day it will come.

Thanks for asking and good luck on your search.

Scott

Tippy

Thanks for the professional responses, exactly what I was looking for!

Chuck W.

Tippy... There are also those like me; 83,000 miles, no top end job (yet) and burns no oil between 5,000 mile oil changes. Do a search, there is a lot of info regarding this subject. Even a poll is out there. Good luck....

omilu

165,000 miles and counting. No valve guide problems, oil consumption has been constant at about a quart every 6k since I got it 4 years ago with 80K. I hit red line at least three times a week, put on new tires twice a year, and love it! I think the guide problem attacks later years, the vario-ram engines seem to have this problem, I am by no means an expert, this is just my perception.

trojanman

Hey Cory...

Some very good advice in this thread... bottom line is that although there certainly is peace of mind that comes from buying a 993 that has already had a top end done, it's hard to say how far you can go on the stock guides. My car's maintenance history indicates that it was having SAI problems at 25k miles, and by the time I did the top end at 39k the guides were really shot. Why so soon? There are a lot of theories, but I'm not convinced there's a single culprit.

As others have said, if you do find a car that's had new guides installed it would be important to know whether they used OEM or a harder/tougher aftermarket version.

Good luck!

99three

Can anyone substantiate this quote???

Davies

No. My '96 w/varioram has 118K miles, burns little oil and is still on original valves/guides. I replaced the exhaust lifters at around 70k (many years ago...).

As has been discussed before, whether or not your car will have premature valve guide issues boils down to luck. Due to huge discrepancies in factory tolerances and hand assembly, some 3.6 engines came out of the factory destined to wear out valve guides quicker than others, regardless of the way they were maintained/driven/babied.

Father of 3

Jeff:

Didn't recognize you with the new avatar. Have some fun at the track?

Cactus

So since the 95's don't have the CEI and the problem goes unnoticed what happens? Do the SAI ports eventually become clogged? I know nothing about engine internals so just curious.

Tippy

Thanks for the additional replies, I figured it would be better to have an engine that already had the work done as most of you agree on. I have found some real good deals out there and the battle rages on for me between the 964T and the 993 N/A.

trojanman

Hey Father...

Yeah, great time... although it's hard to drive her on the street now!

Seriously though, it was a safety and performance driving course and I learned a lot that can be applied in every day driving... and it was a great way to spend a Saturday!

Father of 3

Is that a Mazda 626 hot on your tail?

Sounds like it was a fun day. What track were you at?