Valve guides...

[jgp911]

I'm looking to buy my first Porsche , so I'm looking for some first-time buyer advice. I came across an '89 911 Cab. that was in really good condition. However, in talking to the owner, he mentioned that he had a valve guide go bad about a year ago. He said that he took it in (b/c he saw some smoke), and the mechanic found the bad valve guide and replaced all of the valves. He claims he hasn't had any problems with it since.

Question - is this a common problem? Anything to worry about?

-jay

[Superman]

Some Porsche engines have had premature valve guide wear, particularly in the '70s and to a lesser degree perhaps the Carreras ('84-'89). But I think the '89 cars had the most modern, long-wearing guides. At least that's what I thought I heard. When you rebuild one of these engines you can use guides that are the best ever, typically lasting well over 100K. As it turns out, most of these cars need valve attention between 100K and 200K miles. They can go longer, sometimes much longer, but at 200K miles, the valves and guides will be a bit tired.

[nostatic]

The buyer should have receipts for the topend job, so you can get some idea there (ie, what all was replaced, etc). Assuming it was done right you shouldn't have a worry on that front.

That being said, perhaps the most important thing to do when buying a p-car is to get a good PPI (pre purchase inspection) by a local Porsche mechanic (NOT a dealer). If you say where you're located, someone here can probably suggest a shop or two. It will cost you about $150 or so, but it can catch a lot of potential problems. Typically you will have a compression and leak down done on the engine, but this won't necessarily reveal valve guide problems. Some here suggest actually having a valve adjust (or at least valve covers pulled) done during the PPI so the mechanic can get feel the play in the guides, and also check for head stud problems.

'89 is a great year (assuming it is the "old style" rather than a newer 964) as long as everything checks out.