BenM

Howdy,

New to the forum here, but I've been wrenching on older BMWs for a few years now so I feel pretty mechanically inclined.

Back around the end of January I picked up an '86 SR5 Xtracab w/ around 217K Miles on it. PO said the headgasket and timing chain were done at about 200K or so, so I went on my way. Did a compression test too and all cylinders yielded around 175-180psi, so it seemed like a pretty strong motor, the only thing else I've done was a water pump since it was leaking from the bearing. Unforunately in the last 500 miles or so the timing chain has started making noise and I've been playing russian roulette and bidding my time before doing it.

So last Friday I was getting on the highway to go home from work and the truck started loosing power going up not so steep hill. I was travelling around 50mph and was able to hold it around 35-40 and coast to an off ramp where it promptly died. I was able to restart it a few minutes later and get it into the commuter lot, but it had very little power awith some strange symptoms. If I gave it throttle it wouldn't start, but w/out throttle it would start and idle very low around 500rpm, just barely running. Once it was running if I smoothly got on the gas and got it above 2000rpm it would rev freely with no load on the engine. I took it down the street and it still felt like it had no power, but would still drive if I kept the revs above 2000rpm.

I left it Friday night and came back Saturday around 1pm to try and restart to get it back to work, but it wouldn't start. Had it towed and checked for fuel and spark which it was getting plenty of both. Played around with the AFM and TPS and both read within spec. No water in the distributor cap and rotor and plugs were getting spark. Checked the timing and everything looked good there too. I then did a compression test and the results were less than spectacular:

Cylinder 1 - 75psi
Cylinder 2 - 115psi
Cylinder 3 - 105psi
Cylinder 4 - 110psi

So it looks like my timing chain may have skipped a few teeth and I'm going to pull the valve cover later today to inspect and see if there is any plastic pieces in there. I'm just hoping that I didn't bend a valve on Cylinder 1, but it I'm hopeful since it doesn't look terribly out.

I also don't have a working temp gauge (its on my to do list) so I couldn't tell if it was overheating, but the oil and coolant both look good, and the only bit of milky stuff is a little condensation under the oil cap. Does it sound likely the

Any advice or things I should check in addition to the things I've already mentioned? Sorry for the long rambling post, I tend to search a lot before posting and this forum is full of great info.

Thanks,
BenM

92 TOY

Hey, welcome.

Just have to wonder if they took down the oil pan when they did the timing chain before and was it a new cover? NOT dropping the pan to clean out the crap is by far the easiest way to do this kind of repair BUT just asking for trouble in return.

BenM

Hey thanks for the welcome.

I guess that could be possible, although I'm thinking the PO may have lied and about the TC being replaced. I've got some milkshake coming from the TC Cover so the chain may have already eaten away some of the cover.

I'll be ordering the full kit (Cover, Oil Pump, Water Pump and Chain) from ENGNBLDR in the next few days. Oil Pan should be a cinch to pull with the 4in. suspension lift.

92 TOY

ahh yes, I WISH now that I had a lift, well not really.

The breach in my timing cover is almost unrecognizable and likewise hard to imagine that little crack causing all my problems , but it did....but when I took the water pump off, it was VERY easy to see the crack.

Yep...TED is a great guy, ordered my stuff from him as well....cover with oil and water pumps / timing set / head bolts and gaskets....so you can't go wrong with him....especially much cheaper (shipping wise) to order directly from him versus the EBAY site for him.

BenM

Cool, I've only heard good things about him.

Just pulled the valve cover. and everything looks kosher. Can't seem to find any broken plastic bits down at the bottom, but I need a different light. Also, the chain doesn't feel like it has any slack, any way to determine if its fubar'd?

edit- Just looked down the drivers side of the timing cover and has some huge wear marks where the timing chain started eating through! Also appears to missing the rail. Looks like I'll be ordering some parts tomorrow! :-D

92 TOY

thats the spot!

BenM

Done. Truck is back on the road and running beautifully again, just need to jump the connector and set the timing. Got the parts in last Wednesday and spent most of the day yesterday getting everything apart and then back together again.

The driver's side guide rail had broken into about 15 pieces that were all sitting in the oil pan. Some crap in the pickup which was cleaned with parts cleaner and then blown out with compressed air.

Only trouble I had was figuring how the PS bracket went back together, but once that was done the rest was cake.

92 TOY

good job

BenM

thanks man, hope yours is coming along well.

I determined that it did not jump since the chain was still in great shape, but the driver's side guide rail was completely shattered. Most of it was sitting in the oil pan, with a piece lodged by the passenger side guide rail. Any other way to tell if the motor jumped time? Compression test is great now with 175psi at all cylinders.

Also had the help of a mechanic friend who has many years of experience with Toyota trucks and had just done another 22re timing chain a month or so ago. He said the timing looked fine.

Philbert

iTrader: (2)

glad you got yours running again! That PS bracket is a real pain, and I've done it twice this year...

I'm searching for threads on this topic, as I think I may have skipped a tooth in my timing cover replacement job this month, and my truck just idles up/down/up/down, then dies.

Here's my thread with video on the last page:
https://www.yotatech.com/forums/f116...l#post51464406

Just wondering for those who've done this (and thanks 92 toy for your response on my thread above):
1) How do I know it's jumped?
2) Is there anything else that would cause this issue besides timing chain?
3) Could it be the dizzy is off a couple degrees?
4) If it's jumped a tooth, is there anyway to fix/address/makeup for this without pulling the timing cover off again, as I just buttoned it all back up?

I believe that, when I put the crank pulley back on mine, when the "dot" on the cam gear was at 12:00, the notch on the crank pulley showed about 5 degrees *beyond* the "0" mark, which leads me to believe that the chain may have skipped down below. If it's the case, I'm thinking perhaps I can do this:
1) set engine at TDC using crank pulley notch (and lock it there in gear!)
2) remove valve cover, mark current link that is associated with the "dot" on cam sprocket
3) slowly and carefully remove cam sprocket while keeping tension on chain the whole time...
4) With tension on the chain, slowly and carefully move reseat the cam sprocket one link CLOCKWISE on the chain, then reseat the cam sprocket

Is this crazy? I figure the worst that could happen is I screw it up and have to take off the cover again anyway, but I really don't want to do that if I don't have to....