Timing belt jumped a tooth. Now what?
08-28-10, 12:04 PM
#16
Alright just got the crank pulley bolt off. I filled the first cylinder with nylon rope and turned it so the piston compressed the rope and "gently" broke the bolt loose. Wasn't too bad. I'm gonna go rent the crank pulley puller tool thingy now, but what do you guys think about the positions of the cams? Is it possible that both jumped teeth? Or are they supposed to be offset like that?
08-28-10, 12:33 PM
#17
Lexus Champion
iTrader: (13)
Join Date: Feb 2008
Location: Sacramento
Posts: 2,187
Likes: 0
Received 0 Likes
on
0 Posts
Im not sure about the timing jumping but leave the crank at tdc, and line the cams w/sprockets to the marks behind the cam gears and install the belt. In my opinion it seems like your timing is pretty off. Looks like about a tooth off on the intake cam and 4 on the exhaust cam.
Last edited by soarer13oy; 08-28-10 at 12:38 PM.
08-28-10, 03:27 PM
#18
So I finally found the culprit. A small piece of plastic had gotten underneath the timing cover and slipped between the belt and the gear on the crankshaft. This must have caused the tooth jumping. After setting the engine to TDC, I noticed the exhaust cam had slipped 5 teeth and the intake cam had slipped 4. I just got the front of the engine back together and hooked up the battery to start it up. It started after a few cranks but idled kind of rough. Otherwise it seems to be fine. At least it started. I'm gonna hook everything back up tomorrow and hopefully have it running fully by tomorrow night.
Here's the culprit.
Here's the culprit.
08-28-10, 05:20 PM
#21
Lexus Test Driver
iTrader: (6)
Join Date: Aug 2008
Location: ca
Posts: 1,574
Likes: 0
Received 0 Likes
on
0 Posts
Damn, I always thought the 1JZ was a non-interference engine, is that not true then? Or is it just in the non-VVTi engines?
Last edited by good2go; 08-28-10 at 05:26 PM.
08-28-10, 05:58 PM
#22
Damn, I had that all wrong....I've had in in my head for the longest time the the 2jz's (which I thought he had) were interference engines, but I was wrong about that as well. I looked on wikipedia and seems that only the vvti motors are interference engines. Sorry about that!!
08-28-10, 06:04 PM
#23
No worries man. I checked all the covers and everything and none of them were cracked or anything. I did find a few other small pieces of plastic down there, but that was it. I have no idea where the plastic came from either. It's gray and I don't think there is any other gray plastic around. It must have gotten down there when I took off the valve covers or something. Hopefully nothing got in there too!!! 
08-28-10, 08:30 PM
#25
Lexus Test Driver
iTrader: (6)
Join Date: Aug 2008
Location: ca
Posts: 1,574
Likes: 0
Received 0 Likes
on
0 Posts
Alright just got the crank pulley bolt off. I filled the first cylinder with nylon rope and turned it so the piston compressed the rope and "gently" broke the bolt loose. Wasn't too bad. I'm gonna go rent the crank pulley puller tool thingy now, but what do you guys think about the positions of the cams? Is it possible that both jumped teeth? Or are they supposed to be offset like that?
08-28-10, 10:32 PM
#26
Is it still possible to bend a valve that way though? I've read about the rope trick before, and it seems to work with most people, but who knows really.
Last edited by OneJay; 08-28-10 at 10:55 PM.
08-29-10, 08:33 AM
#30
I didn't even think of that. Now I'm just remembering how it sounded like it was running kind of rough when I started it back up! Hopefully I didn't just dig myself into a deeper hole. I guess I'll hook everything up today and hope it works. I really don't want to have to pull the head. 