Liz,
I'd take Jim up on his offer and at least look at his car. Do some further research on compression/leak down results....I think you'll find that opinions vary especially with regard to valve guide wear. All 993's, including 95's, are prone to premature valve guide wear. One of the few Porsche OEM parts on these cars that need replacing with non-OEM parts.
~Dave

 

Fixed that for you...




Andreas

 

Oh yes, there are some cars stateside that have been modified (unmodified?) to originally designed, ROW, SAI pump free status. As delivered, all 993s sold in the US and Canada were fitted with the SAI pump I believe. I'll let the OP guess who's car may have been so modified.

 

Hey-ho, thanks for the additional info.

Unfortunately it turned into a game of he said—he said and TruSpeed wasn't giving an inch on the issues Tony identified. (I got pictures today finally and the front differential was WAAAAY more than just seepage.) There's just too much at stake to risk getting the car and have it turn out to need a valve job in the first year. I mean, avoiding that is what you expect when you buy an almost $40k example with 37k miles. If I'm buying a $30k car that needs a $10k valve job, then fine, c'est la vie.

So, the car's back on the market. Really sick at heart about it, as it had the perfecto options for me and the M030 is just impossible to find.

I have PM'd Jim already! But I'm wondering if I should go back to looking at the C2. They're inherently more competitive in autox because they're lighter and throttle-steer better, but I had the idea that the C4 would give me that edge at the 2-3 rainy events/year in this part of the world. Thoughts?

Cheers,
Liz

 

There is no question that ALL USA and Canadian 993's (1995-1998) have the SAI (electric smog pump) system. Just for the record, I have been trying for years to decipher if a car has worn out valve guides without taking a valve cover, rocker arm and valve spring off to check the valve to valve guide clearance/play by hand.

In most all cases engine leak down and compression tests will NOT reveal valve guide wear. If talented, a technician can sometimes locate worn valve guides with a vacuum gauge.

 

Tony, is it right that leak down and compression are more about the current state of the motor? And the SAI test you do is predictive, sensing the problem before it's impacted performance.

Cheers,
Liz

 

You are getting some great advice here on this great forum! And you sound like you have been doing your homework on researching about these great cars! If I knew what i have learned on this forum before I bought my car pretty much blindly, it might have been a different story. I did not know about detailed PPI from certain shops, compression leak down test, or SAI issues, etc. I put down a deposit on my car, that I have not seen, just to have first dibs on it in May of 08. Maybe it was the "red" interior that turned half of the people off and nearly affected me also until I saw it in person. Previous owner had all of the service records from a "reputable" shop and all but I did not really know what to look for at the time. But it all worked out for me as I have no major issue with the car except for the slippery slope of upgrades. So my .02 cents worth is that it is a good market as a buyer and I would value a rennlist higher milage car that has a rennlist history and people here can vouch for it than a car that has lower milage that also carries a price premium with not much history. But it also help if you don't mind getting your hands greasy or know someone here that can help you service the car because it can get expensive really quick if you send it off to the shop for every little issue. Not that I am plugging anyone's car here, the no affiliation thing is in place, and best of luck to you on your search.

 

Interesting questions Liz. Yes, the engine leak down and compression tests are run to tell you the current state of the engine BUT cannot tell you about the valve guide wear. If the valve guides are really bad, I assume the compression test could possibly show some variations between the cylinders but I have yet to experience this condition with corresponding results. The Callas Method, checking the 993 SAI system with the PIWIS or PST-2 tester while utilizing the SAI pump in relation to the O2 sensor/s on the Oscilloscope, has proven to be very accurate but is only accurate when compared to my previous documented results.

To answer your question, it's a test to tell us the current condition of the SAI system. Unfortunately, the valve guide wear allows oil to leak past the guides and into the exhaust ports, the oil get's burned, (turned into carbon) and ends up in the SAI ports resulting in clogged SAI ports. So what I am trying to say is, is that the Callas Method is not a direct test of the valve guide wear. It is actually trailing the valve guide wear. When we get a negative result on my test, we know the valve guides are worse than the result. There is actually some delay between the two but I cannot quantify this yet.

 

TCallas - Affiliation to MCallas in sealy, tx, I suppose? I bring mine there for allaigment and balance.

 

That C4 is perfectly optioned but the good news is you can easily upgrade the suspension of any 993 to better than US M030. As for the sport seats, they are out there albeit very costly. Walking away from a car you have your heart set on is not easy, but it sounds like you are making the correct choice in this case.

 

Thanks for this info, Tony. I've been told this in round-about ways before, but I've never had it explained.

 

Yea, a $40k car should not need that kind of work, it was obviously a neglected car. This is why it's important to follow Porsches guidelines of changing the oil once a year regardless of miles, along with bi-yearly fluid changes.

There are well optioned C4's out there, I stumbled on mine, it's optioned about the same, but I got the OBC as well.

Don't listen to people about the C4 not being competitive. It may not turn in as fast as the C2's, but you can put the power down sooner, & it trail breaks better. I've flat out won a few of my local Auto-X & am usually the fastest or 2nd fastest 993 there. This is the 100% stock class. Mine is also the LOWEST HP car with the HIGHEST miles on it. The bad part about my local class is we run with the Boxters, so even the new 2010's will be in our class, & they are tough to beat!