rdlsz24

I've had a timing chain rattle at startup and on the highway when I am over 2k rpm and off the throttle. I've had it since I've had the truck. Anyway, today when I was 5 miles from home I noticed I was losing power up a hill and then I came to a stop light and it died while I was coasting to a stop. I noticed right before this happened the rattling was louder and happened in a bigger range than just around 2k rpm. I tried to start it and it wouldn't without me giving it a little gas. So I limped it to a side street to get out of traffic. At this point it sounded really bad, like a loud banging when I would give it gas. I popped the hood to take a look and didn't see anything out of the ordinary. So since I was almost home I tried to limp it on the back roads. I went about another mile seeming somewhat normal and then it died again. Turning the key made the loud nasty noises again so I called a tow truck. I got it in the garage and pulled the valve cover expecting to see my guides are toast but they look good. They were new last January when I changed the headgasket:


When I shine my light down there everything looks normal and the tensioner looks good. I am at a loss here and I need to get it fixed by Monday preferrably or I will have to get my GTO out of storage and drive it in the crud Any ideas?

Rob

thook

Put the crank at top center on the compression stroke and see where the rotor is pointing. It should be pointing at the #1 spark terminal. If not, the chain has jumped teeth and the timing is way out. And, if that's the case, most likely you have bent some valves. But! No point in jumping to conclusions until you've looked at the rotor position.

Also, is the driver's side guide rail wobbly or nice and stationary?

rdlsz24

Both guides seem good. I will check where the distributer is pointing tomorrow. Keep the ideas coming.

Rob

thook

Well, honestly I really don't have any other ideas.....personally. I really think that's what's happened. The loud banging you hear/heard, if I'm correct, would be the valves colliding with the pistons....probably. Unless, it's so out of time it's spark knocking and, of course, dying and making lots of valve chatter.

There's also the possibility that even though it's jumped time, you may have not bent any valves....if it's only jumped a tooth. Much more than that, I don't believe it would even run.....at all.

Good luck to you.

91Toyota

fuel pump went out? fuel pressure regulator (does it have one?) is shot causing excessive amounts of fuel to enter chambers causing a clunk? Timing way off?

I would turn your engine over by hand. If you feel that a valve hit the piston your screwed. I think if a valve bent it would not shut all the way...so maybe check your valve clearances? Just a thought....could be many possibilities. Good luck!

thook

Good points.

There's another way, if you don't feel anything (I didn't), to tell if any valves are bent that I can explain once you've made some determination whether or not the rotor's off.

91Toyota

Oh, btw, my stepdad had a bad misfire in his toyota...94 22re, and he got it home. Then he took it to a shop and they fixed the problem. $150, and 4 new spark plugs later and he was trucking again...lol

stupid_mud_gremlins

put a wrecking bar on the crank bolt and move it side to side a bit and see if it makes noise, might be a rod bearing....

rdlsz24

I turned it over two times with a bar on the crank pulley and didn't notice anything out of the ordinary. The rotor is pointing to the number 1 terminal at TDC:
.
The cam sprocket dots are also just before 12 o'clock when the crank pulley is lined up with 0 as well.

When looking at the guides closer I did notice this:


The bottom mounting hole on the driver's side guide is broken. I stuck a flat piece of metal down the side and was able to move it around. Could this be a culprit?

Rob

rdlsz24

Should I just try replacing that guide and see what happens? What I don't get is why would it make a banging sound and not want to run? Do the guides really do that much?

Rob

SEAIRESCUE

Start wrenching. Can't ride the way it is now. When the cover comes off, you will get your answer. Put some threadlock on the guide bolts this time if you find loose bolts. Yes, the guides are there for a very good reason.

MY $0.02

thook

A broken guide wouldn't make a banging sound nor the cause the motor not to run. They only keep the chain running it's course, however that's mostly important on start up until the tension builds. The timing chain rattle would be from that......which is what led me to think what I had, but obviously that's not the problem.

Drain a few cups of oil and take some pics at different angles of light. See if there's a copper hue in the oil. Take note (and a pic) of what first comes out. I'm wondering if you threw a rod or spun a bearing.....something in the bottom end.

Wait, wait.....when you turned the crankshaft by hand, was it easy to turn or was there resistance from compression?

91Toyota

Yeah...my guide was broken and I couldn't even tell. A guide will NOT cause it to not run. Running is your main problem right now. Do you know if you are getting spark?

If you want to see if it jumped at all your can look at the cam gear. When you see the dot look for the colored link and if it isn't there spin it around another time until you find it. It is kind of hard to tell. If it is off one...well you know. I doubt it though.

rdlsz24

When I turned it by hand it seemed normal. It was hard to turn on compression and it got easier on the exhaust. Wouldn't the timing be off if I jumped a tooth? Or is it possible for it to happen and not get out of time? The timing seemed spot on. The sound I hear does sound like what I would imagine a piston hitting a valve to sound like (since I've never actually heard that sound). I would much rather have it be a top end issue than bottom end. I'm going to test the compression here in a minute. This engine was rebuilt by the previous owner (a Toyota nut) less that 30k miles ago, so I'm hoping it's not the bottom end.

Rob

91Toyota

So what was the compression...it couldn't be worse than mine.

And yeah...I don't think it jumped a tooth...I think something else is going on here. It's better to check though. Maybe a stuck valve?...causing it to back fire (I don't know if it could???) but did you check your valve clearances?

I could LITERALLY stick my finger between the valve and the rocker...I wish I would have taken a picture!
It still ran though

rdlsz24

There is compression on each cylinder so I pretty much ruled out a bent valve. I kinda figured this since my timing wasn't off. So I drained a little oil into a clear container and let it sit for a minute:


FLAKES!!!!!

Looks like a bad bearing. Is it normally like this? Meaning a bearing just goes bad all at once? I thought it was a gradual thing. It only has about 25k miles on the rebuilt bottom end.

Rob

91Toyota

I wouldn't think a bearing just goes bad. Sounds like someone can't rebuild an engine!

rdlsz24

Would a bad bearing make it not want to run? Do you agree that the oil indicates a toasted bearing?

Rob

91Toyota

It's hard to tell...and I am no means an expert...cause I have never taken the bottom end of an engine apart. I'm trying to visualize what a bad bearing would do. I would have thought if a bearing went bad then the engine would just run horribly...but not not run. I think someone someone will chime in though.

rdlsz24

If it is the bottom end, I have a line on a cheap short block 22RE from a '92 two wheel drive. Will it work with my '88 22RE with 4x4?

Rob