Timing belt job just done. Blown engine or savable? This is interesting guys!

[2001LC]

I was hopeful someone in mud spotted this thread before today. Someone that had seen one, where fully bank flat-lined, and why would come forward. But with the holidays seems so many aren't around.

Are you going to be resetting the timing for this customer? Interested in seeing what you find.

I am! I wanted to first have reasonable evidence the engine did not interfere. That I've done.

In your picture of the FSM, it has a notice for interference engines. Is that manual for an 06-07? I wouldn't expect that note in the non-VVTI engine manual.

That was from a VVT (Toyota online).

BUT: Toyota considers all 2UZ interference engines.

I just took this picture from my 2001 FSM hard copy. See Notice: that is the inference warring. Even though I'm 98% convinced we do not interfere on a non VVT 99% of the time. Also 90% sure we do on VVT. I follow procedure out of fear, .

I know guys in mud have spun the crank with belt off. No interference! But the test would be have a piston at TDC and spinning its cam. Also accounts breaking belts under load passing on HWY and no damage. But still what if valve gap at limit (minimum) to lobe of cam. Valve spring weak. Could we get one that did interfere, perhaps.

Toyota thinks we can.

 

[suprarx7nut]

I was hopeful someone in mud spotted this thread before today. Someone that had seen one, where fully bank flat-lined, and why would come forward. But with the holidays seems so many aren't around.

I am! I wanted to first have reasonable evidence the engine did not interfere. That I've done.
That was from a VVT (Toyota online).

BUT: Toyota considers all 2UZ interference engines.

I just took this picture from my 2001 FSM hard copy. See Notice: that is the inference warring. Even though I'm 98% convinced we do not interfere on a non VVT 99% of the time. Also 90% sure we do on VVT. I follow procedure out of fear, .
View attachment 2171252

I know guys in mud have spun the crank with belt off. No interference! But the test would be have a piston at TDC and spinning its cam. Also accounts breaking belts under load passing on HWY and no damage. But still what if valve gap at limit (minimum) to lobe of cam. Valve spring weak. Could we get one that did interfere, perhaps.

Toyota thinks we can.

Good clarification, thank you! I probably read that page on my 99 manual during the T-belt job, but I guess it didn't register in my long term memory.

 

[GTV]

I know guys in mud have spun the crank with belt off. No interference! But the test would be have a piston at TDC and spinning its cam.

If you need to remove a head would you mind sticking some putty on a piston, bolting the head back up and rotating the crank with the valves open? I for one would love to see some hard data on this subject.

 

[97 AZ LC]

In your picture of the FSM, it has a notice for interference engines. Is that manual for an 06-07? I wouldn't expect that note in the non-VVTI engine manual.

I'm not sure what year the manual is but Toyota has always said that non-VVT is an interference motor - but it just doesn't seem to be in real world belt failures. Never mind - already clarified.

 

[2001LC]

Would clay to measure piston valve clearance be accurate IDK ?

I'd not likely pull the heads on this 05. If bad we'd likely just look for a donor as first choice.

I will be blue printing a 2UZ-fe vvti engine one day. I've two on stands now and one gasket kit.

BTW: Plastic gauge, is how bearings are gauge.

 

[suprarx7nut]

I'm not sure what year the manual is but Toyota has always said that non-VVT is an interference motor - but it just doesn't seem to be in real world belt failures. Never mind - already clarified.

Would clay to measure piston valve clearance, be accurate IDK ?

I'd not likely pull the heads on this 05. If bad we'd likely just look for a donor as first choice.

I will be blue printing a 2UZ-fe vvti engine one day. I've two on stands now and one gasket kit.

BTW: Plastic gauge, is how bearings are gauge.

Am I oversimplifying this or could you just measure with calipers? You could measure valve extension above (below when installed) the head surface, and then compare to the valve cavity depth in the piston.

Either way, I suppose you need a head and block opened up.

 

[kruisinkid]

playing the uneducated devils advocate: ive only been this deep on a 2F, obviously pre belts/chains. I have to believe this is so badly off its timing on B2. is that possible just looking at all the alignment/timing marks on the various pulleys? it seems like the injectors are dumping fuel on the wrong cycle and thats why everything is so wet. are the cam shaft pulleys 1:1 to the crankshaft pulley? or is the cam 4:1 to the crank and the cam pulley is one revolution off?

 

[bwell]

When I did my belt on my 2000, admittedly I didn't do either cam or crank seals because didn't feel necessary. Are the cam gears and crank pulley key'd so to speak? Did they swap them or something. They had to of reversed something for it to suddenly run like this. I agree with last poster something is 180 out of where it should be. If one of the cams is completely out of sync, it probably does have shot valves/head is potentially toast on that side.

 

[GTV]

Would clay to measure piston valve clearance, be accurate IDK ?

It’s perfectly accurate. That’s how high performance engines with high lift cams/stroker cranks/long rods/milled heads are built.

 

[Julian Stead]

Hi Paul, why don’t you pull the cam cover off so you can have a good look.

snapped camshaft? check exhaust to inlet cam timing marks etc..

 

[white_lx]

Long shot: L & R cam sprockets have different part numbers. Any chance they got mixed up while replacing the seals?

 

[2001LC]

Okay. When I first saw no compression on BK 2 and good BK 1. I'm thinking bent valves.

Leak down test indicated valves are good. I'm thinking bK 2 camshaft out of time. First think I look at once cover off, is mark was good, although seems off just a hair as I pictured above. So the hair off off is cam BK to in relation to crank I took as a clue. I checked and CAM is keyed/pinned.

So today I pulled BK 1 cam cover. Set both marks of cams to the "T" and the corresponding dot on low cover, they lined up. The "T"'s are timing marks for when lower cover is covering crank sprocket. So Okay could we be 180 off on crank. I set screw driver in #1 spark plug hole. It raised as I turned the crank and topped out as I hit dead on on all marks. The top dead center on compression stock. So it's dead on.

So I pulled lower cover and lined up crank sprocket, and both cams sprockets.

So this belt is dead on. The lower cover with zero timing mark must not be perfect line up. So it gives false reading. Because the real hard mark is the crank sprocket and the dot on oil pump housing.

 

[AlpineAccess]

Okay. When I first saw no compression on BK 2 and good BK 1. I'm thinking bent valves.
Leak down test indicated vales are good. I'm thinking bK 2 cam out of time. First think I look at once cover is mark it was good, although seems off just a hair as I pictured above. So the hair off off is cam BK to in relation to crank I took as a clue. I checked and CAM is keyed/pinned.

So today I pulled BK 1 cam cover. Set both marks of cams to the "T" and the corresponding dot on low cover, they lined up. The "T"'s are timing marks for when lower cover is covering crank sprocket. So Okay could we be 180 off on crank. I set screw driver in #1 spark plug hole. It raised as I turned the crank and topped out as I hit dead on on all marks. The top dead center on compression stock. So it's dead on.

So I pulled lower cover and lined up crank sprocket, and both cams sprockets.

View attachment 2171828
View attachment 2171829
View attachment 2171830

So this belt is dead on. The lower cover with zero timing mark must not be perfect line up. So it gives false reading. Because the real hard mark is the crank sprocket and the dot on oil pump housing.

Wild - so timing install was done correctly.

Good news is it sounds like the motor is fine but likely still something timing related or damaged during the job. I'd go to looking at electrical systems near the timing belt job. Sensor wire get clipped? I'd expect a CPS to throw a code immediately.

No codes, right?

 

[Eicca]

Is it possible that the wheel things that the cam/crank sensors measure are installed incorrectly?

That still wouldn’t explain poor compression in bank 2. There’s something mechanically afoot.

 

[2001LC]

Correct compression is mechanical test, so not electrical or sensor.

So I'm scratching my head, but back to first thought when I found BK 2 has near zero compression, BK 1 good compression and leak down test said valves did not interfere. I did re visited cylinder 6 with camera this morning before pull covers. To see why 35% leak down. Found as expected scoring on cylinder wall. Not a big deal and not sometime going to keep from running. I have a video of scoring and here the still show. Very hard to see but it;'s there. Scoring is between the lines, traveling up and down the cylinder. I do need a better camera.

But @Eicca I thing you were first to say and my first though was right!

Did they do cam seals while it was apart? It's a long shot, but I seem to remember a story where a cam sprocket got installed incorrectly so the cam itself was way off even when the marks lined up.

But if that were the case, I imagine it would've run like complete crap from the very start, instead of gradually getting worse.

My though then was cam not pinned, but then I saw it's pinned.
Although BK 2 cam is pinned, which indicate it must be timed right, it's only thing this could be.

So I with BK 1 cam uncovered I took a closer look at pins to compare. I noticed a difference.

Look:
BK1. This pin is recessed about 2mm flush (if not deeper) with inner recess of sprocket

BK2 Pin is out pressing against nut. Not recessed at all. But was before disassembly, based on next picture from mechanic that replaced the cam seals..

Now look at BK 2 the mechanic text Cairo (owner), before disassemble. It's recessed or flush with inner recess of sprocket and centered just like BK 1 now is.

 

[GTV]

It backed out enough to slip?

 

[2001LC]

I thought the knock pin was fixed in cam. But now I'm thinking it must be removable (floating). Anyone known?

I only see one reference in a 2000 FSM of a searchable copy. It just states "Align the camshaft sprocket knock pin with the knock pin grove of timing pulley"

I don't see it in my best online parts source diagrams. Anyone know if knock pin is available from Toyota as a separate part?

I'll pull belt and cam sprocket in the morning, if I get time. But looks like knock pin must have floated out hole/keep of cam, as sprocket was torque down. My bet is, Pin being out of hole/keep of cam, is now riding on solid steel face of cam. Nut may have pressed knock pin into cam holding it to sprocket by pressure against nut/washer, rather than pinned in the hole..

Sprocket not correctly time to cam, just happens to have intake valves open on compression stroke of each BK2 cylinder, is my guess!

I'm hopeful this is issue and new pin can be found tomorrow locally.

 

[Ambledog]

That pin should not be out that far. I don't recall the pins being loose when I pulled my cam pulleys, picture is before I removed the pulley. Clearly set further in. And then next picture is after removal. Yeah, I know the T isn't the timing mark. And first pic is left side, second pic is right side.

 

[suprarx7nut]

I thought the knock pin was fixed in cam. But now I'm thinking it must be removable (floating). Anyone known?

I only see one reference in a 2000 FSM of a searchable copy. It just states "Align the camshaft sprocket knock pin with the knock pin grove of timing pulley"

I don't see it my best online parts source that has best diagrams. Anyone know if knock pin is available from Toyota as a separate part?

I'll pull belt and cam sprocket in the morning, if I get time. But looks like knock pin must have floated out hole/keep of cam, as sprocket was torque down. Pin being out of hole/keep in cam, is now riding on solid steel of cam. Nut may have pressed knock pin into cam holding it to sprocket by pressure against nut/washer rather than pin in hole..

Sprocket off time to cam, just happens to have intake valves open on compression stroke of each BK2 cylinder, is my guess!

I'm hopeful this is issue and new pin can be found tomorrow locally.

I don't think I took off the cam gear on the 2UZ when I did my T-belt, but in other engines I've always seen that knock pin in the cam gear floating. It's always been a slip fit and a separate part. In the ToyoDIY diagrams I'm not seeing a part number so perhaps the 2UZ is fixed in the cam.

Either way, That pin should have plenty of engagement in both the cam and gear. If it's slipping out enough to allow cam movement I'd expect a canyon of a gap between the gear and cam as though they weren't tightened.

*edit: correction, I did take off the cam gear and the pin did stay in the cam for me.

 

[SouthJerseyJim]

Did you take the belt off and set the cams to make sure you aren't 180 off? Engine harness wires, fuel injector wires or throttle bottle wiring damaged in any way? If it ran good before timing belt replacement and now it doesn't run at all after I think we know why.