Valve clearance inspection (1 Viewer)

[64fabius]

Hello,
Is there a procedure to inspect and adjust valve clearance of 2UZ FE engine when the heads are been removed from the cylinder block?
Otherwise, should the adjustment of valve clearance be done only with the heads installed on the cylinder block?

 

[RapidRob]

Possible, but not worth the trouble with trying to turn the cams and get them to stay where you want them.
Also the head will need to be firmly held down while you work.
Bolted to the block with the timing belt etc installed will be the best way to do it.

 

[excessive]

From what I've heard & Read, the tolerances on the 2UZ are so good from the factory, that unless you have the heads off, its a waste of time to adjust the valves (even though there is a procedure for it)

 

[awesomeissquid]

Possible, but not worth the trouble with trying to turn the cams and get them to stay where you want them.
Also the head will need to be firmly held down while you work.
Bolted to the block with the timing belt etc installed will be the best way to do it.

Just to clarify, yes the heads need to be installed along with the camshaft but the timing belt should not be installed.

You check the valve clearance by rotating the camshaft and using a feeler gauge. If anything needs adjusted you would remove the camshaft to access the valve buckets and shims.

On the non-VVTI engines you should not have any concerns about interference with the valves and the piston heads. I am not sure if the VVTI has a specific procedure to perform the test to ensure there is no interference. The FSM has the procedure listed out at the front of the engine mechanical section.

 

[2001LC]

I've not looked at procedure in FSM, in years. I did once speak with a machinist on head rebuilding of VVti. He suggested, I let him spec the heads on the bench. Seem, he has way to lock/clamp them on bench. Otherwise I agree w/ @RapidRob, install heads on block to use as your beach. Easier on back, on engine stand, but most roll around. Greater leverage, engine mounted to frame in the engine bay.

If VVTi, make sure to follow and make sense of FSM recommendation. To date I've not tested, VVti for interference. I just had a VVTi R&R, oil pump service. That I did last week. T-belt was off. So I temporarily install belt, to spin crank to get TQ bolts off. I don't have the guts, on someone else engine to spin crank or cams indpendly. I wish I had years ago tested, when I had two VVTi engine I was not going to use.

 

[64fabius]

My 2UZ FE isn't a VVTi. When I purchased the heads, the vendor told me that valve clearance was already done by grinding mechanic. So, I installed the rebuilt heads without checking valve clearance again. But vibration, engine power loss, poor engine performance, idling issue appearead during the first test drive.
Then, I had to do the reinspection of valve clearance and I found 14 wrong shims: 5 in #2 head and 9 in #1 head. So I had to do a new valve clearance meauremets and adjust shims.
In my opinion any valve clearance was done by grinding shop because it must be done only with the heads on the block as described in FSM.

 

[2001LC]

Don't use them again.

 

[2001LC]

My 2UZ FE isn't a VVTi. When I purchased the heads, the vendor told me that valve clearance was already done by grinding mechanic. So, I installed the rebuilt heads without checking valve clearance again. But vibration, engine power loss, poor engine performance, idling issue appearead during the first test drive.
Then, I had to do the reinspection of valve clearance and I found 14 wrong shims: 5 in #2 head and 9 in #1 head. So I had to do a new valve clearance meauremets and adjust shims.
In my opinion any valve clearance was done by grinding shop because it must be done only with the heads on the block as described in FSM.

Grinding valves, reduce gap. Unless they grind the stems head. Which we're not "grind to gap" heads valves. You're likely to tight. Checking is easy. Change bucket shim, will be PITA, since cams must come out. Use table in FSM for shim conversations size thickness. Good luck

BTW: why were heads rebuilt?

 

[64fabius]

These were my heads.......

 

[kuelblaz]

I concur w others ... On the block. Looks like you were loosing a little compression there ... pretty rare to see valves burnt up like that. Did you determine cause?

 

[2001LC]

These were my heads.......

View attachment 3805299

View attachment 3805300

Was intake manifold removed, prior to burnt exhaust valves. Like for SAI, knock sensor or starter service?

 

[64fabius]

On my LC 100 there is a dual fuel system: LPG and petrol.
In my opinion the very high temperature of LPG combustion caused that.

 

[64fabius]

Was intake manifold removed, prior to burnt exhaust valves. Like for SAI, knock sensor or starter service?

I do not understand why if intake manifold was been removed, after exhaust valves would have burned.
Can you tell me why?

 

[2001LC]

I do not understand why if intake manifold was been removed, after exhaust valves would have burned.
Can you tell me why?

So often improper procedures used.

1. Dirt/sand, not cleaned from top of engine. "Falls into intake ports, damages valve seats, cylinder walls & rings.
2. Intake manifold gasket seal surfaces, not perfectly cleaned. "Vacuum leak"
3. Reuse, old intake gasket. "Vacuum leak"
4. Intake gasket, not oriented properly. White tabs up. "Vacuum leak"
5. Intake manifold bolts and nuts, not evenly torque or left loose. "Vacuum leak and sucks sand"

 

[64fabius]

I've done valve clearance as described in FSM. But when I checked ECU via Techstream, I found a difference in fuel trims between bank 1 and bank 2 as you can see on attached picture.
In the past I changed the fuel injectors with genuine new ones , all intake manifold gaskets and MAF.
In your opinion, what and where

could be the issue?

 

[2001LC]

I've done valve clearance as described in FSM. But when I checked ECU via Techstream, I found a difference in fuel trims between bank 1 and bank 2 as you can see on attached picture.
In the past I changed the fuel injectors with genuine new ones , all intake manifold gaskets and MAF.
In your opinion, what and whereView attachment 3818543 could be the issue?

You've a modified fuel system, which I've no experience with, nor any idea what's been done to run on LPG. So I'll not be of much help!

That said:

Have you check for vacuum leaks?
Your statements, indicate; Machined heads, were done poorly. Compression test may be very revealing.

A snapshot of just FT. Isn't very useful, as we've no idea of the may other data points. But yours does look like a STFT1 very rich. So your LTFT1 should be negative, to correct STFT1. May be just point in time you took snapshot, IDK.

I'm more interested in FT, while cruising steady on HWY. I use a BlueDriver wirelessly connected to my iphone. I watch FT, RPM, MPH, ECT, IAT. Then I can go back and study logs of entire drive. Focusing on where RPM & MPH indicate I held steady throttle at HWY speeds on flat HWY.