My 993 News: Top End Rebuild Looms
 

I just did every bit of outstanding maintenance on the 993 in May/June and am ok with the state of the car.
However, I wanted to get the compression checked so I did that today up in Wisconsin. Excuse for a good drive.

It turns out my #4 cylinder is showing 20% loss. The other 5 are between 4-7%. Kind of sucks. But hey it is a Porsche. And I am at 134k miles now.

I am a little bummed that the time has come for a top end because of the cost. I do need a new flywheel but I was hoping to drive at least for a couple more years before dropping the king's ransom.

I am comfortable working on most parts of the car but not with engine work at this point. I am just not there yet with my skill set.

I guess that is the cost of playing this game at this point. Gotta start saving the pennies.

--Michael

Michael,

I went through this last year, and while it was pricey, the result is fantastic. It's a little painful, but since you know what you are getting into, it will be alright and you will be glad once it is all over.

FWIW, I have a set of stock cams in great condition, with the woodruff notch, just search the classifieds. Due to backdating, and the spacing, I couldn't reuse my cams.

Good luck!

It's a rite of passage, a rebirth. You will be new again.

I'm right behind you.

If it makes you feel any better, I'm right there with you. At the very least I need an engine-out reseal, but if I'm paying for that much labor there is lots more "while you're in there" work to add onto it.

I don't think that justifies an top end....is it missing, fouling plugs or burning excessive oil?

If the car is running fine, 20% one cylinder could have been a bad reading.

I have 180k and in 3,000 miles its has not burned a drop and my oil is so clear its hard to read it on the dip stick..car runs perfectly. I do have a 95 with the emissions blocked off.

Typically the flat 6 engine can easy do 300k before it needs to be torn down if maintained correctly and the driven regularly.

...exactly. I'm just waiting for something that needs the engine out then do it all. But the original is just running so good.

I bit the bullet last year and did a comprehensive mechanic overall of the entire car including a complete engine rebuild.

The bill was steep for sure, but boy is it nice to drive a mechanically as-new 993. Then again, the bill was probably less than the lease payments would be for 2 years on a new 911, which I'm not really interested in, so.....it's not too bad.

If you're keeping it for the long haul, it's cheap in the long run.

Good luck and welcome to the club :cheers:

You could..
 

Michael writes, "It turns out my #4 cylinder is showing 20% loss. The other 5 are between 4-7%. Kind of sucks. But hey it is a Porsche. And I am at 134k miles now.

You could do a temporary fix on #4...probably needs a valve, or both valves, maybe rings. Then keep saving your pennies, and in the future, do the complete engine.

Thanks for the thoughts. I did notice that the exhaust valve on #4, and the area around it, was very crusty when I took the exhaust manifold off a year or so ago to flush the SAI system. I am pretty sure in fact that I have had lower compression in that cylinder since I bought it 5 years ago.

I can live with it until I have the money together next Fall. That is the target at this point. I have driven the crap out of it in its current state.

On a positive note, I passed emissions two days ago so I am set up with a legal car until I do the rebuild. That is a load off my mind.

--Michael

What running symptoms caused you to contemplate this rebuild? Leakdown testing is notoriously variable and is a weak secondary diagnostic tool.

I did a leakdown on my brother's 993 during a PPI a few years back and one cylinder came back low. The shop suggested that a piece of carbon may have gotten stuck. Look around and clean it up next time you are in there and that just may be the problem.

BTW, my bro's 993 runs great today 4 years later.

Good question. The idle is lumpier. The acceleration at around 4.5-5.5k seems a little rougher.

The exhaust valve on #4 is surrounded by crusty,crystal stuff. I noticed it a few years ago when I had the exhaust manifolds off.

Other than that, I am going on a hunch. I am by no means a mechanic, just a very interested enthusiast who likes to get his hands dirty.

--Michael

My Idle is a little lumpy too- I think a LOT of these car are when they warm up. I am going to change the plugs and see if that fixes it. I'd go slow on this unless you're burning oil.

993 are always a little lumpy, Clean out the idle valve and replace your distributor caps and rotors, No biggie. I would not go any deeper if you are not throwing emission relevant misfire OBDC codes.

I just did caps and rotors. Wires are good as well. I am throwing 1411 a lot. Other than that, no codes are showing on my diagnostic tool.