matt777

I look at a lot of ads for 993's and I don't recall seeing one mention of a top end rebuild. How real is this valve guide wear problem? Are people just living with the oil consumption? Any thoughts would be appreciated. Thks. Matt

Mark Wilson

Mine had a warranty top end at 36K miles for excessive oil consumption and cel.

Texas993

In some cases the cars have had a top end and don't want to advertise it, other cases they need a top end rebuild, and in most cases they don't need one at all. The CEL is what gets most people to do a top end so they can pass emissions testing.

My car (85k miles) had a top end rebuild at 77k miles.

The valve guide issue is very real, but it depends on how the car was driven. A compression/leakdown test is the best indicator of valve guide wear/leaks. [EDIT: The experts say I am wrong about this.]

Crimson Nape Racing

compression or leak down tests will not show valve guide wear. The only way to tell is oil consumption, which you cannot test for.....

jimbo3

+1. You could run it up to near red line in 2nd gear and look in the rear view mirror for a puff of smoke when you suddenly let off the throttle. It's not a definative test, but indicative.

cmoss

the play in the valve guides can also be measured...

mine was done at ~65K

melman911

What does a top end rebuild usually run?

TRINITONY

4 - 6 k..

only real way according to one of the pros on here, is to do the 'wiggle test'.

vjd3

I had mine done (58k miles) for $3500, huge difference, car runs great, has not used a drop of oil in 7000 miles. The mechanic showed me the guides, they were totally shot.

luvmy356

Why wouldn't a seller advertise the top end rebuild? That with all the receipts were the only reason I bought my Targa.

According to the receipts, mine was done at 69k, and since the motor was out, they replaced all the clutch components even though it was still good, plus they pulled the cylinders, resealed the bottom of motor and new through bolts and seals. My motor is bone dry. No rings but the compression was 195-200psi across all cylinders when I just did the 90k service, so hopefully that means the rings are still good.

Napa Valley Realtor

My big question is if the top end rebuild fixes the problem? ie do they use better guides (different) when they do the rebuild, or is the same thing going to happen in another 50k?

Butzi

Depends who did it & what parts they used.

Most on this board will suggest to use aftermarket (non-OEM/Porsche) guides (bronze something). I would propose that Steve Weiner is one of the experts here, so I'll direct you to his website: http://www.rennsportsystems.com/1.html Scroll half way down to the "A Word about Rebuilt-Overhauled Engines" section.

Also, a search of Steve's posts, with "valve guides bronze" as the subject results in MANY hits. Here's one: https://rennlist.com/forums/showthre...+guides+bronze

dcdude

And if any oil does bypass your new hard valve guides, you gotta drive it hard to keep stuff from hanging around in the secondary air injection system. Some say cruising around 4K RPM as well (boy, THERE was a discussion!)

Few things in life are certain, but if you do the above, you've done your due diligence, which is all you can do, which is the only way all of us Type As can sleep at night. Hmmm...P-car therapist? There's a career idea!

Adrienne

My story is about the same: I did my rebuild about 30k+ miles ago. It still does not burn oil. I (meaning, my mechanic) installed non-OEM guides. Runs like a champ at 143k miles now!!

Nuff

I just got a '95 993. While I was looking, I saw a few ads that advertised a top end rebuild ....