Howdy folks,

TL;DR. Sheared teeth off timing belt. Trying to save my pride and joy.

long story
ive got a fun one for ya. I have a 1987 4runner with a 2LT 2.4L turbodiesel swap. I bought it swapped like this and ran it trouble free for about 2000 miles. I was driving a bit ago and all of a sudden my 4WD light came on but the transfer case lever was definitely still in 2WD. I reached my destination, shut it down, and then went to drive home a few hours later. A minute into the drive my whole gauge cluster went out accompanied by a rattling/high frequency knocking noise. I pulled over, stopped/started about 5 times trying to troubleshoot to no avail. I limped it home with the noise worse under throttle and the car down on power until about half an hour into the drive when the rattle got a little better, and the car seemed to return to normal power. I parked at home about 20 mins later, then upon my next attempt to drive the car flat out refused to turn over. I dropped it at my local shop who attempted to turn it over by hand and found that it would turn over backwards but not forwards. At this point I got the “hey this is probably gonna cost you an arm and a leg and maybe not fix things” I had it towed home and dug into it myself. Upon removal of the timing belt cover I found the belt had cracked lengthways all the way around and a section of about 10 teeth had sheared off but were all still held to each other. This pile of teeth was surrounding the crank which is what I think was not letting it turn over. I have replaced the belt and confirmed that the engine turns over smoothly by hand. I then tried to start the engine with another car jumping the 4runner’s battery. It felt like it almost started but didn’t. I tried bleeding the fuel lines and most recently did a compression test. I found ~250psi per cylinder which is obviously not great but I think should be enough to start it. I’m at a bit of a loss right now and really want to save this thing. Please help!

 

Do some research to see if this is an interference engine. If so it's time to pull the head, you likely introduced your valves to the pistons. You'll need at minimum some new valves. You may need a new head if the damaged valves have also damaged the head. You may even have rods that are damaged. Just because they all come to the same TDC measurement doesn't mean she's not got stressed rods from the impact which could let loose at any moment.

If all you need is some new valves and a head gasket I'd say it's worth the risk if all the piston height's check the same

 

That mating surface on the 2L head is pretty flat, not much forgiveness. If you could snake a boroscope into the cylinder you should be able to see if there was impact. maybe the chain store has something in their tool loaner program that'd work

 

More details! I’ve done a compression test and found ~260 psi on all cylinders. Obv the engine is cold because I can’t start it. I know this is much lower than the factory rating but this engines certainly seen some years. This tells me that (I hope) things aren’t completely trashed. I’ve just installed new batteries to give it the best shot of turning over. I think my fuel pump may be out of sync because even with low compression I think it should at least try to make some explosions. I timed it with the mark on the case but is there a chance it could be out of phase (ie a full roatation or two out of sync with where it should be and therefore putting fuel into the wrong cylinder at the wrong time?). Thanks yall!