loftygoals

Awesome info to know. Thanks!

Well, like I mentioned, I'll know the state of the head soon. I do find it interesting that you've seen the most damage on cylinder 4 with broken T Belts. I wonder if this didn't happen at a really low RPM. It's an automatic, so the motor probably hasn't seen a lot of high revs.

-bj

whalebird

I can't really explain the #4 thing. Kinda like the #2 rod bearings. It's just my experiance and probably does not apply as often in the rest of the world.
I am certain that the leak-down test would answer you question, but it's like an AIDS test. It just confirms your doomed. Pulling the head and tidying up everything is not a big deal if you are resolved to doing it and it sounds like you've come too far to short-stop your efforts. You are doing a good thing and for many reasons. You are helping someone out - Imagine the joy of someone giving you a Porsche. You are keeping one of these cars on the road as they normally go to the crusher - I think in time you will see these cars go up in value and the ones that are still around will be rare. You should take tremendous joy in your satisfaction of being a selfless, others-centered person. You will be rewarded in many ways. I wish I were there to help your wonderful endeavor.
keep us posted and good luck - you probably have a bent valve. It may be easier to source a good used head and just do a swap. Plus you will have an extra head laying around for the Clown Shoe.

loftygoals

Actually that one isn't too hard to explain. It doesn't get the oil it needs. That's why a lot of 944 spec guys drill an extra oil passage in the crank for the #2 bearings. What is really interesting is that some really early 83's with the forged crank had this passage drilled from the factory. Why did Porsche stop doing it? You got me.

Yeah, pulling the head isn't a big deal. I'm a mechanic. I own a race shop here in Dallas. I primarily work on BMW's but I'm never afraid to get dirty with another make. Once you've seen enough engines, an engine is just an engine.

That's not to say that certain motors don't have certain nuances. That's why these forums are so great--I can fill the gaps in my knowledge with the info from others.

Me too. I'm getting tired of wrenching 10 hours a day by myself. I'm hoping to have a second mechanic later this year, but for now it's just me.

I have a spare motor sitting in my warehouse next door. I just don't feel like swapping it in, because it's a used spare in unknown condition. Besides, if I rebuild the top end and put all fresh gaskets on the car should be reliable for years to come. Spending the few extra bucks now could save our friend who will be receiving the car a lot of money down the road.

-bj

whalebird

Cool. I have been a Porsche and Mercedes factory tech for 23 years. I know what you mean. The novelty wears off of whatever fancy car your working on. Gear lube dripping on your head is a mess regardless of what it drips out of. Good luck again and I will keep a close watch on this thread.

loftygoals

Head is off!

The good news: the head and head gasket were in great shape!

The bad news: the block is toast.






The scoring in the wall on #2 is a lot deeper than the pics makes it look.

I think it's time to drop in my spare motor.

-bj

Jay W

Total bummer. Is the metal that scratched the bores still in there? I think I saw some shiny metal chunk in one of the pictures. If it is then is it something like part of a spark plug?

loftygoals

I think the metal you see is a chunk of the bore itself, but I'm not sure. There is lots of damage besides what is seen in the picture. There are deep verticle grooves all the way around the bore. It's in pretty bad shape.

-bj

M758

Probalby detonation on number 2 leading to cracked rings or some FOD injestion.

Yeah, block is toast. However the crank may be serviceable.

whalebird

That bad injector may not have helped washing the cylinders down. Keep us posted.

carlege

Turned into quite the project hasnt it?

loftygoals

It's just par for the course. I've yet to have a project that doesn't spiral into a huge event of some sort.

-bj

peanut

she's very fortunate to have you and your Wife as friends . Thats a good thing you're doing .

Re the low compression I'm inclined to think stuck valve ? even with no rings fitted at all I'd expect better than 30lbs !

Hope you don't end up doing a load of work on the head too.
good luck