a4sfed928

I just purchased a 79 928 that was not running and now I think I know why it was neglected. I did manage to get it to run for about 30 seconds just to verify all internals then on to the cooling system. I was pressure testing the cooling system and after repairing several leaks the last one was small but still evident. I could not locate any external leaks but could hear a faint drip. I finally found it to be coming from inside the oil pan! I removed the oil plug and sure enought water. I have not removed the oil pan yet but I suspect the block is cracked. Is there a possibility to weld the block if the crack is not within the cylinder?

Garth S

That's a very tough one to address ....
By the time you have the engine out and stripped to allow an examination, hoping to find and repair any and/or all of the cracks, it may be far easier and cheaper to visit ebay: a complete early 16v engine generally draws a very low price.

GlenL

Could always be a head gasket.

Curious: Has anyone had a cracked 928 block?

Head gasket leaks are not unusual.

Garth S

First thought was head gasket also; however, I couldn't visualize the return path to allow a coolant drip into the pan. Still, the gaskets are far more likely to fail than having a freeze cracked block ..... although IIRC, someone recently wrestled with one such problem here in reviving an OB.

GlenL

I was thinking maybe water was leaking into the oil return drains from the cam.

Or maybe there are broken rings and it's going through a piston.

mulik51

Last year I got almost the same thing on my engine. I didn't see that there was water in coolant(Ok, let's not talk about that...) instead of coolant, and after winter, when I drained oil I got water coming out. I was chasing the problem for some time, but didn't find anything. In the end, I bought 4.7L block and put everything on it(almost complete now). The 79 "leaking block" is in my shed. As soon as I will finish putting 4.7L engine in my car, I will disassemble the leaking block and see what happened to it. Yeah, head gaskets had bumps in them....is it normal?

Klim

a4sfed928

I pulled the oil pan today and pressure checked the cooling system to look for the leak. It was dripping by the pistons on #1, #4, and #5 cylinders and I did not see any cracks from below. Pulled the plugs to see cylinders filled with water so it looks like it was overheated but I dont know how bad. It did start and run on all cylinders and sounded good. Are the engines junk after an overheat? Should I just pull the engine and install a used one, and save the old one for a build up? What about a later model engine inplant?

FlyingDog

Pull the engine, pull the heads, and see if it's just headgaskets. Marc at Devek commented in another thread about overheating. He said headgaskets go first, before damage to the block or heads.

PS, swapping another k-jet engine is shouldn't be hard or overly expensive. L-jet or LH-jet will be a wiring a tubing nightmare.

a4sfed928

The plan for this car was to use some of the interior parts for my other 928 and turn this one into a track DE car. I had planned to keep stock parts in it but strip it bare and add a cage and seat. would the plumbing still be a problem for a late model engine?