clutchsmoke

Need a little help but I'm fairly sure that the timing belt went. Truck first started to overheat and I suspected the thermostat. Put a new one in and while I was at it I replaced the alternator because the one in there was a junkyard / emergency road repair. Fired the truck up and it was noisy and sounded like the noise was near the front of the engine ( see where this is going?) It stopped making noise and ran ok for a little bit but then started surging followed by an abrupt silence. Some smoke rolled out from under the hood ( uh- oh) that kind smelled like burnt wiring.
This is what has me tripped up, would the cam belt slipping cause something to overheat and cause the smoke? Could it be the idler pulley?

BTW it has too many miles on the belt, I thought it went to 100 thousand but it is 70, my bad.

thook

Could be two different things....the smoke and surging/abrupt silence.

Why don't you pull the front timing cover back and varify the position of the cams and rotor against the crank at top dead center?

Are you sure you had the alternator hooked up correctly?

clutchsmoke

The alternator was or is hooked up correctly, it's hard to screw up. The plug goes in one way and the large wire goes on the post. I'll pull the cover off tomorrow and look at the belt. I'm just hoping something didn't fry and it's just the belt.

thook

You're right...it is, but you don't always know where someone's at mechanically. So, was just asking.

You don't have to pull the cover all the way off. In fact, just turn the crank to TDC and check the rotor position. It should be a the #1 spark terminal on the dist. when on the compression stroke, or 180* opposite that on the exhaust stroke. If the belt has slipped, likely the rotor will be off. Then, if you need to, pull the cover to inspect it.

BTW, I do think it could be the idler pulley just from your discription. If it seized up, I could see where it would burn the belt.

clutchsmoke

Thanks for posting, it gives me some hope. Also another symptom: it cranks over but sounds funny. It's cranking over quicker than normal, like as if there were no spark plugs ( or the cam timing is off). I'll provide an update when I know more.

clutchsmoke

Man, the belt was FRIED! It melted to the cogs and had to be scraped off. The water pump seized causing the belt to get really hot and then melt/smoke. As bad as it sounds I'm happy that the burning smell was not any electrical components. So remember that a burnt wire smell could be your timing belt cooking.

thook

Lol....okay, I'll remember that.

Glad you found the problem and it's not terribly serious.

Cranking over faster than normal....like you had no plugs....meant you weren't getting any compression. Obviously, the belt was fried. The abrupt silence you mentioned before had me suspsicious of that because I've read about what happens when the belts breaks. I've had the timing chain on my 22re break before, so same thing in both cases. No compression.

leebee

just of the valves!

lee

thook

Aye, lad.....not sure whatcha mean d'ere.

But, it takes the synchronization of valve closure and upward piston travel to create compression within the combustion process. Neither the valves or pistons alone will create compression.....one being dependant on the other. So, therefore, no compression at all, eh.

clutchsmoke

Just a quick reminder: if you need a timing belt, do it yourself. It was so easy and I know I did a better job than anyone that I could have hired to fix it. I bought the NAPA kit, everything was made in Japan ( execpt the gates belt) and all parts appeared to be of high quality. Can't sit here and chat, gotta go drive...

thook

"....gotta go drive....". Hehe.....spoken like a true Yota lover.

Sounds good to me, for what that's worth. Congratulations.