993 head overheat !Need expert advice!

[adamb113]

I was alarmed this weekend to find out a friend decided to buy 1 964 instead of a 993 ( when he really wanted a 993) because of research he did on 993's. He said that he had found out that 993's have chronic head overheat problems. I am also in the market for a 993 and was unaware of this problem. Can anybody fill me in on the details? Did Porsche address the issue and make improvments ( i.e. a 98 is better than a 95)? What's the relative time period for this problem to show? What does it do? valves? How much of the population does it effect? Are there any symptoms you can look for when shopping for one? DId these issues start with the 993's not the 964's?
Thanks
Adam

[maxnine11]

there are no head overheating problems with 993s.
are you (and he) serious ??

[adamb113]

I was surprised too! That is why I threw the question out there. So you have never heard of any problems with valves and heads on the 993? I would be surprised if he was totally off, he is a long time Porsche owner and pca member. So there must be somthing to his findings.
Please Please prove him wrong. I really want to be able to buy a 993 without worrying about big issues like that. My 73 Targa needs soembody to play with.
I'm interested in any other thoughts on the subject
Take Care,
Adam

[85Gold]

Like all 911 variants some 993s suffer from premature valve guide wear. Your friend may be talking about this however the 964 has the same problem.

Peter

[maxnine11]

Adam, you probably misunderstood your friend, or he misunderstood someone and passed the (mis)information on to you. I have never heard of a head/heat problem. A LOT of guys drive these to the track, flog the car all day, then drive home.
A certain percentage of 993s have been known to have premature valve guide wear. The guide material too soft. It seems to be hit and miss. Some people need the valve guides done at 40k miles, while lots of cars are at or near 100k miles and are still fine. Sounds like an echo from the '80s Carrera era, doesn't it??
There is also the chance of the air ports in the heads and cam boxes getting plugged with carbon. If the car has high oil consumption (from worn valve guides or whatever) , this can contribute to the secondary air injection (SAI) ports getting plugged and triggering a CEL.
If you really want to have a 993 some day, you might try to find:
- a car that has had the valve job and ports cleaned already
- a car that doesn't have high oil consumption or SAI issues (this would require an honest seller- good luck )
- have some money stashed away for a valve job if the problem does arise.

If you have a car with no SAI issues, there is a procedure to flush the SAI ports to keep them clean.

PS... I hope your friend isn't up at night worrying about cylinder- to -head and cylinder -to -case leaks on his 964.

As with pretty well every series of 911, including the new water-cooled models, there seems to be a couple of expen$ive issues for each particualr model that rears its' ugly head on a percentage of the cars after awhile...but the percentage seems to get overblown somewhat on the internet.
And, as with every series of used 911, it's a good plan to have a reserve fund for potential repairs. They're great cars with awesome performance and loads of character... but they're not perfect.

max

[adamb113]

Thanks Max. I think I will sleep better tonight.
P.S. How much does a valve job cost?
Adam

[maxnine11]

The total for a valve job is mostly labor charges, so it will depend on the hourly rate of the shop. I have heard different people say anything from $3000 to $7000. ( i have a feeling the large number may have included a few extras ''while they were in there")

[Dp2boy]

I have to concur with the other guys. Of all the peculiarities associated with 993's having the heads overheat is not one I've ever heard discussed.

[tshih]

The only thing I don't like about the 993 versus the 964 is the 993 seems to have more weird body noises (windshields creaking?) despite being stiffer overall in design and has grown heavier (versus the RSA 964 that I have). There is a huge price difference for comparable mileage cars. I would get the 1993-94 964 over a 1995 993 since the HP difference is small and the reliabilty issues are the same.

[Tom W]

Regarding the "problem" with the 993s, i say "poop". I don't believe it. I've spent a couple years on Rennlist since buying my first 911 and have never seen any issues with overheating and very few posts regarding valve guides.

That said, I have both a 964 and 993. The 964 at 72k miles and a lot of track time is in the early stages of bad valve guide wear, but not enough to force the work be done yet. The 993 is close in mileage but has not problems. I like the 993 much more than the 964.

You've got to remember that posts regarding problems are common because people are looking for help solving them. That doesn't mean that a significant percentage of cars are falling apart. Posts about how wonderful your car is running are boring so they don't get posted.

[john walker's workshop]

993 heads are stamped RR350, the alloy used in 930 heads. they are made to withstand hotter temps.

[adamb113]

Thanks for all the info! Looks like the consensus is that there is nothing to worry about.