PRSWILL

I have the light coming on for SAI for the first time with 109K - I got a quote to clear the ports from my VERY highly rated shop for $ 500 bucks. I clear the code and it goes off about every 300 miles- so I don't think it's too bad. I may have the lower valve cover gaskets done then too as I am starting to leak a few drops onto the heat exchangers now and then, but the car burns almost no oil- less than 1/2 a quart every 6,000 miles.

nine9six

If the bold text is true, why did you need a valve job and guides? To most, that is what is considered a top end job.

I can understand gaskets, plugs n wires, lifters, chain and tensioner while the motor is out...

goofballdeluxe

You can have good leakdown numbers and still need to relpace worn valve guides, no?

Steve Weiner-Rennsport Systems

Thats correct.

Foxman

1/2 quart every 6,000 miles? Are you rolling the car down a hill? Dont you change the oil after 5,000?

I typically go trough 1 quart every 1,000 to 1,500 miles, or perhaps even just 800 miles when I really drive hard. That's my experience driving three different 993's ranging from 65,000 to 130,000 miles. Put some electrical tape over the yellow light and forget about.

Jlbarnett

I just undertook this project as a DIY. All in it cost me $5K. The only things I had a shop do were the actual machine work (Rennsport) 1200 dollars, cleaning and flow-matching the injectors (Witchhunter) $150, upgrading the engine carrier (Rennline) $300ish, and refinishing the engine fan $200.

That being said, I did change every seal possible short of splitting the case open as well as replacing numerous fasteners.

Pichu

Do you have a break down of the other $4K? I'm planning on doing the same thing myself to make the engine 'as new' (ie refreshed heads).

Except my car only has chain cover leak (and of course dreaded SAI but it has not come back on yet after 500KM's).

Quadcammer

horrible advice

Pichu

It's not the worst advice in this thread. There is alot of cars (even in this thread) that probably didn't even need a top end rebuild (especially the 27K mile one!!). I can agree with getting better valve guides/head rebuild as all the heat and wear/tear is in the heads of air cooled cars.

But to do a 15K rebuild is just no necessary on many of the cars that I've read about here on Rennlist. The were done for 'peace of mind', not to keep the 993 driving.

Ivan J

I have about 40k miles on my rebuilt top-end. I can go 5k miles without adding one drop of oil between oil changes, despite the fact that it sees 6k rpm going up-hill almost every time I drive it.

My rebuild was about $7k. The engine needed a complete reseal at 50k miles (about 6 years ago), so the top-end work was simply a matter of "while you're in there...".

Pichu

Adding zero oil between changes is not the same thing as my 993 doesn't use any oil.

pp000830

I change my oil once a year 5000 miles +/-. Never need to add oil between changes. The last time I just added enough oil to get the gauge to float midway between top and bottom when the engine is hot. Didn't seem to move lower over time, however this is a subjective measure. Car is just short of 100K miles seems to run strong. I drive it almost every day a short distance.

Steve Weiner-Rennsport Systems

Totally concur.

For the benefit of others reading this thread,

Excessive valve to guide clearances results in excessive valve temperatures and for exhaust valves, this is critical since these are not fuel-cooled like intake ones are.

If one has ever witnessed the utter carnage resulting from valve failure, this problem would become MUCH clearer due to the financial impact.

Porsche delivered many cars with valve guide clearances beyond their own published wear limits so this is not a trivial matter.

Ivan J

OK, I'll make it simple for you... It uses such a small amount of oil, there is no need to add any in order to keep the level comfortably well above the minimum mark. I would estimate less than 1/2 quart in 5k miles

JaramaGeorge

Living in SoCal and just did the SAI triggered top end rebuild for about $8000 with 72,000 miles on the car at a local Porsche speciality shop. No external oil leaks before the rebuild, just annual oil changes at about 3,000 miles per year. I've only put about 500 miles on since the rebuild so to early to tell if it uses any less oil.

If you're in the LA area and looking for a good affordable shop try MKS in Camarillo.