Hi folks, I have come in need of knowledge. I've spent some time digging around, and think I have a pretty good idea what happened to my '85 SR5 Pickup with a 22re in it.
Background:
I inherited the truck in rough condition after it had been sitting around the California Sierra foothills for about 2 years, during which time it was stolen by meth heads and recovered at some point. When I got the truck, it didn't seem to need much work to get it road ready, but I changed the oil, checked the coolant (looked good, clear, green, full to the top of the radiator fins when cool), and after driving it a while, replace the spark plugs.

A few weeks ago, we had a pretty nasty storm (by California's standards), and I drove the truck ~45 miles down to see my parents, everything seemed fine. I had glanced at the temperature and oil pressure because this is still a fairly new vehicle to me, and I haven't quite sorted everything out. Temp looked fine, oil pressure looked low (btwn 1/4 and 1/2), but after reading around here, it sounds like that's somewhat normal?
Showed the truck to my brother, drove it to the store, parked, had dinner, and I decided to take off.

It's pouring pretty hard, and I'm focused on the freeway and other traffic, and less so on the dash. I get about 15 miles down the freeway when I hear some clacking coming from the engine, and figure I better pull over. Pulled off the freeway, and made it to a gas station where I look around in the engine bay and don't see much amiss. Checking the temp here would have been a great idea, but that didn't happen. Called a buddy, and he said if it's still making power, bring it to his shop a few more miles up the road than I was planning on going. Figured, why not, it's still mostly running, and wasn't thinking about the cam chain guide issue that is well known.

Back on the freeway, but I'm flooring it in 4th, and barely keeping 50mph, at which point I see my temp gauge pegged hot. Great. Pull off again, and at this point the engine is stalling and sputtering and doesn't want to keep running. After pulling into a neighborhood, I tried restarting, but it needs significant throttle to keep running, but it's running rough at best. I ditch the truck and come back the next day, open the radiator cap, don't see any coolant, coolant over flow is empty, and there's some splashed coolant around it. Under the oil cap for the engine I don't see much chocolate milk or signs of coolant, but I don't think that's really enough to go on.


I haven't had time to work on the truck but I've been theorizing a few things, most likely of which is that my cam chain guide broke, causing the chain to rub through the front cover and break open a hole to the coolant jacket(?)
It's my understanding that if coolant mixes with the oil in these engines, the crank bearings can be toasted pretty easily.

Alternate theory: I had replaced the accessory belts on the front of the engine, and was pretty sure I didn't over tighten them, but squealing noises had been heard from the engine before, and I figured they were wet belts just being annoying, and the noise went away after a few seconds. From my reading, it turns out that could could have actually been the water pump bearing going to crap because of too much tension from the belt, and maybe causing the pump to stop pumping and then some over heating to happen, and maybe that's the cause of the clacking, low power, and stumbling of the engine.

My game plan is to drain the oil and see what comes out - if I see coolant, I think we'll have a decent idea. After that, removing the valve cover and looking down into the cam chain tunnel, I should be able to see if the guide is broken or not, right? Somewhere in here I'd like to run a compression test to see if my head gasket is blown.

Am I on the right track with this? Is there anything else I'm missing? Do I really have to drop the solid front axle to get the oil pan out? I thought I read you could lift the engine or transmission a bit to snake it by.
If the head gasket or lower bearings are toast - I just don't have the time or space to do a decent rebuild, so I'll probably be shopping for a good working or re-manufactured engine - sounds like I should avoid the new cast heads and stick to an original, but are there any decent shops on the west coast that have stock?

 

your best bet for seeing if the timing chain guides are broken is to remove the oil pan to see if you find part of it there. you might get lucky and find that chunks are broken off at the top but from what i remember you can't see the entire chain guide from the top.
when my old 84 (back in 93) had similar issues i dropped the pan and found chunks of an old timing chain in the oil pan