BMillar

Took the '91 944S2 in for what seemed to be a lower balance shaft cover leak. Mechanic called me to the shop after he finished the job because it continued to leak and he advised he had discovered a crack in the block just above the balance shaft cover. (it may not have ever been a leaking balance shaft). He used a camera scope to show me a location above the balance shaft cover on the side of the block where he said it appears to be cracked and advised that he had never seen this before. Is this a known/common issue? Motor has about 200,000 miles on it.

Lots of recent work has been done on the car to restore it to very nice condition both cosmetically (and I had thought, mechanically). Mech is advising that we should pull the motor and see if it can be welded, but in any event he says must re-build the motor. Wondering if anyone has experienced a similar issue, what are my options, do I need to rebuild and what should an engine rebuild cost? Sorry, no pics. I didn't think to take any. Can go back and do so if the brain trust needs 'em.

Ez8

If it's cracked and they can repair the crack then yes it will need rebuilt as to get to the crack and do the work the block will need to be stripped.
Cost is likely to be in the many thousands of dollars range.

Look at it this way...with an S2 you're in a better position to do an LS swap than most people. Silver linings, right?

jeyjey

If you're rebuilding anyway I'd start with a junkyard block (rather than your cracked block). LS would be fun too, but a lot more work.

Breakaway944

Pictures are always helpful.
"appears" to be cracked and cracked are two different things!
What cylinder is it near? Could it be coming from the oil cooler? A bad casting mark could look like a crack and oil would naturally follow it.
It is more likely that the oil cooler would leak before the balance shaft. The main leaking from the balance shaft is usually the o-ring at the back of the shaft.
I would CONFIRM the leak is coming from a crack before you pull the engine - it is expensive by the time you are done with the "while I am in here..." Use your camera on your phone to record and try and catch the leak "red handed"
One of the members here has a web site newhillgarage.com where he goes through the oiling system on a 944 (not S2 but block the same concept). This might help you chase it down.
Look at pictures of other blocks, in the area where it looks cracked, and see if there are funny marks on the other blocks or if they are smooth.
Good luck, I hope it is not cracked!

Tiger03447

Try putting some fluorescent dye in the oil. If it's cracked, the dye will show it. Use black light on it to pinpoint the leak. Preferably with the engine running and the car is on a lift where the leak? can be viewed easily. This diagnostic might just save you a BUNCH of money~! Hoping for a gasket leak! Good luck!

Jmag21

It wouldn't be that much to rebuild if you only replace the block and can reuse everything else. I would go ahead and do all the seals and gaskets if I was rebuilding, and I just did, but I also did higher performance pistons, rods, cam etc. Some places throw away blocks because they're so cheap. An S2 block is probably harder to find, but there should be turbo or other options that can be machined to the 3.0.

thomasmryan

imho, the balance cover end seals should have been designed similar to the cam shaft end seals.

I would need to go from 'think' to 'know' before the motor is pulled. there are way too many possible leaks in that area to assume.

I would remove the heat shield, clean the area, start the motor and look for the first drip.

MAGK944

+1 been fooled by this before and I’ve been around these engines for years. So as others have said, confirm it is an actual crack before moving forward.

BMillar

Thanks. This forum is awesome. I believe I'm going to get the car back home and start with a thorough cleaning, further assessment of the leak and the fluorescent dye in the oil. From what I was shown, I definitely cannot tell whether its an actual crack or a casting mark as was suggested. Excellent tips!

michaelmount123

Poor man's fluorescent dye:

I've mentioned this several times over the years, but I don't think folks realize how quick, easy, and effective it is to identify the source of an oil leak.
1. Clean the area (well) with brake clean and air, or any solvent and a brush followed by air.
2. Using baby powder in its container, "puff" a light coat of powder throughout the suspected area.
3. Start the engine and you'll see exactly where the leak originates.
4. Wonder why you never used this method before.

Like others, I suspect there's no crack, but rather a leaking seal.
MM

jhowell371

I remember that trick, you must be an Old Timer too. There used to be a spray on deodorant that left a white powder type residue that worked great for getting back in places but the name escapes me in my dotage.

cpcca

All great ideas. I've used the brake kleen/baby powder thing too. Don't give up yet. Besides if you "just do an LS swap" you must take all the Porsche emblems off and replace with Chevy bow ties. And then find a new forum..😪
Hope you find it. GOOD LUCK!

CyCloNe!

😳 Trying to tell me something? Lol, jk.


I would rebuild the motor or find a running replacement these cars are going up in value and S model cars had some of the lowest production numbers. If you really wanted to do an LS swap now would be the time but don't do it unless it's something you really want. Mines almost finished and I have no regrets doing it but I enjoyed 2 modded turbo cars before making the jump. If I had another turbo or an S2 I wouldn't have done it. I did it because I wanted one for 10yrs and started with an S1 car specifically for this type of project. Honestly the motors in these cars are great just too many owners that didn't take care of them.