2UZ VVTI Ticking/ Clacking/ Tapping Noise after Cam Seal & Single Cam swap (1 Viewer)

[xcmountain]

OK, short story long.

I wanted to replace leaking 2uz VVTI cam seals, they were making a mess. I got the parts, watched the video, and thumbed through the FSM. I DID NOT want to replace the water pump and all the goodies because it had already been done 40k ago (documented). And yes I should have waited until another 50k to even touch the bloody thing.

Tore into the motor PS first, and done and done, oh crap I forgot to push in the seal between steps 7 & 8. Undone, done, and redone. I was tired and figured ok only a few more hours. Started the DS, done and that's weird the intake came riding high and won't seat. A little torque per the FSM 12 ftlbs, still nothing. Pulled it out and laid it on the bench, came back and I now had the new and unimproved 2 piece intake camshaft (crap).

Spent some time teetering between new ($400) and used (super scarce), found a guy, and ordered a set of the used ones.

Shipped late, and finally arrived. I started the re-install, finished the reinstall, and then the moment of truth, crank it! Well, the good news was that the motor runs smoothly, the bad news is I have an early Land Rover Series II diesel knock.

GXOR said ohh you should've measured the valve to cam spacing, and you'll surely need to order valve spacers. Ok, a trip to harbor freight for feeler gauges and a micrometer. Measured the valve spacing and they are ALL within spec.

NOW, working backwards in my mind I only touched a few items that would cause such a noise.
1. the motor ran fine, with no noise other than the valvetrain which is faint on the 2uz, and I can still hear it under the diesel tapping.
2. the 2uz is an interference motor and it would be impossible to get a cam cycle out of sequence because it's 2 turns of the crank to 1 turn of the cam. meaning the cams cannot be advanced far without the engine needing to be turned to help make space.
3. all pulleys and bearings are tight and smooth.

Now my only valid theories are these, I used and reused the timing belt tensioner. It is not leaking and it is FIRM when using the benchvise to compress and reinsert the grenade pin. I did randomly notice the timing belt tensioner pulley seems to go in and out of phase with the tensioner removed and hand turning the engine. What I mean is that with the tensioner removed it is loose and floppy one portion of the belt cycle and then when I turn the crankshaft it gets tight and won't budge, this may be wholly unrelated, but worth mentioning as the noise it makes when I push on it rapidly sounds like the same clacking I here.

So the question is what am I missing, Is there another component I am not accounting for in my search for the cure? The noise is definitely drivetrain and not valve train Faster Noise not slower.

 

[xcmountain]

Project update, after reassembling for the Nth time I approached the run it till it doesn't mindset. I dropped my child off at school and the GX Gods gave me a code. P0010 & P0018. Ordered a CHEAP set of Amazon VVTI actuators to see if that clears it up. Will follow up with OEM once I know.

 

[2006 LX470]

I had a similar thing happen to me and I some how bent two intake valves on the driver side. I think I missed the step of moving the crank counterclockwise til the timing mark is at 12 o'clock while I worked on the cam seals.

I'd do a quick compression test on the cylinders on the driver's side to rule it out.

Did you put the bolt in the exhaust camshaft gear prior to removing the cam caps? Did you remember to remove the bolt after the cam caps were torqued after replacing the cam seal?

 

[xcmountain]

I had a similar thing happen to me and I some how bent two intake valves on the driver side. I think I missed the step of moving the crank counterclockwise til the timing mark is at 12 o'clock while I worked on the cam seals.

I'd do a quick compression test on the cylinders on the driver's side to rule it out.

Did you put the bolt in the exhaust camshaft gear prior to removing the cam caps? Did you remember to remove the bolt after the cam caps were torqued after replacing the cam seal?

I am worried I have in fact done something bad. The cam broke almost dead center but the noise seemed more forward, but we are talking about 10" from the center of the valve cover to the cam gears. To your question of whether I place the service bolt, No I missed this step but found many online who had also missed this step. Apparently, it is just as easy as removing the cam, setting backlash, installing the service bolt on the workbench, and reinstalling. Yes, the service bolt came out prior to use.

The noise does have a lifter tap type of sound.
I ran the motor with no serpentine belt to eliminate possible accessory noise, but the noise was still present.

I have done all things EXCEPT the compression test. The motor runs smoothly, and neither performance nor fuel economy is affected.

 

[Wadepat2]

Find the issue?

 

[FrankieJoe14]

The only thing I have to add that does not help your cause - when my head gasket was bad, two of my cylinders were running at 90 psi, while the other 6 were at 190+

It ran smooth as silk. You would have no idea.

I think you need to do that compression test.

 

[xcmountain]

The only thing I have to add that does not help your cause - when my head gasket was bad, two of my cylinders were running at 90 psi, while the other 6 were at 190+

It ran smooth as silk. You would have no idea.

I think you need to do that compression test.

Sorry, I forgot to update. I HAVE NOT found the issue but have a theory. I took her to Lexus to see if they could figure it out. After a few hours the Shop Foreman came out and we talked. He said I have no idea, then I told him the story, then he said ok, chances are you tweaked a valve, they are super strong but the are pretty flexible. So it’s sealing and not causing any great loss but also tapping. As far as why the P0018 code is lit he said go back and measure the tabs on the donor cam and make sure the spacing for the cam sensor is the same. (I have yet to do this). The. He went on to say we could spend another 3/4 hours and tear it down to see what’s what or you can leave no charge. I was honest and said for four hours at $269 an hour I could likely replace the motor with a donor, and he understood. So I’m running it until it doesn’t.

 

[2001LC]

My first thought of sound: Valve adjustment or low oil.
1) Cam to bucket clearance, which worn cam lobe or a shim missing is a consideration.
2) Check oil level, type & weight. VVT actuators can be sensitive to weight/pressure.

I'd then check:
Then check compression, scope any low. Looking for, valve contact.
Then check oil pressure.
All good, pull head cover(s), Check cam lobes, clearance and timing of gears.

 

[2001LC]

I'll add. Finding a good engine, is more difficult than most think. Especially ones, made in Japan.

 

[2006 LX470]

Did you do a compression test yet? AutoZone rents out testers through their Loan A Tool program. Very easy to test and will either rule some things out, or point you in the right direction on what to do next.

 

[xcmountain]

My first thought of sound: Valve adjustment or low oil.
1) Cam to bucket clearance, which worn cam lobe or a shim missing is a consideration.
2) Check oil level, type & weight. VVT actuators can be sensitive to weight/pressure.

I'd then check:
Then check compression, scope any low. Looking for, valve contact.
Then check oil pressure.
All good, pull head cover(s), Check cam lobes, clearance and timing of gears.

Have not done a compression check, I left that for Lexus to do, but they didn’t and also advised it would t likely be helpful (I still could, and it would verify a bent valve and or not sealing in the seat causing leak down)

It does have that low oil sound, but she has plenty.

Cam to bucket was verified when I installed the new to me cam, they are ALL in spec.

Timing of gears, through trial and error I’ve found it runs the same set one tooth left or right of TDC. Scissor gear backlash was reset (because I missed that step on tear down #604).

 

[xcmountain]

Did you do a compression test yet? AutoZone rents out testers through their Loan A Tool program. Very easy to test and will either rule some things out, or point you in the right direction on what to do next.

No, but should be the last thing I do or can do at the moment. I didn’t realize AutoZone had them for rent. I was going to purchase one from HF.

 

[xcmountain]

I'll add. Finding a good engine, is more difficult than most think. Especially ones, made in Japan.

Yea my eyes are focused on another 05-09 GX470 as the donor.

 

[2001LC]

Yea my eyes are focused on another 05-09 GX470 as the donor.

First off, let me say. I applaud, you doing a VVT cam seal leak job in the first place. This is one of the most technical and labor intensive services on a 2UZ VVT, short of head replacement or engine rebuild.

Proper diagnostic of why the valve tick, if first up!

Inference:

I'd move on to compression test, leak down any bad or to low and scope with a camera.

If inference found. It may than be best to find and engine. Just head or heads, would also be a consideration. Provide piston tops and cylinder walls look very good. But head R&R, is a "roll of the dice". If a valve hit is seen, on top any piston.

I was able to score a very good 06GX w/98K mile, hood on, fresh kills' engine. Good, in that perfect service history of all oil & filter services. Fresh kill, being it was in salvage yard within 4 months of totaled due to side-impact. Hood on was and engine never sat outside in the elements. The VVT intake manifold rubber gasket, shrink with time and when cold. If water sit on top of engine, it can seep inti intake ports. Rule of thumb; If water gets into engine, run engine within 3 weeks. The longer it sits, the more likely it will be a smoker.

Oil flow issue:

Since oil level and type all good. I assume you see pressure on dash gauge. Than very likely, oil starvation due to oil type, sludge or pump not the issue. At least not at oil pump or crankshaft.

Why P0010 & P0018, if oil good. When not present before service. Is your biggest clue. Since your using the ones you took out, they should be just the same condition.

We must to consider, oil flow through the cam shaft(s). Could error there have been, and in the assembly of cap and oil passage from/through head on each side.

Or was it, both intake cams replaced. I was unclear on why you replaced in the first place. Were not timed correctly. Which may have lead to interface. The one tooth either side, could be the issue I "suppose". Could you have gotten a bad cam(s). With clog in passages!

One other thing to consider. Used, VVT timing gear on used cam(s). A machine shop that specializes in engine rebuilds. Warned me, DO NOT reuse VVT cam gear actuator, from engine that had coolant in oil. The number one reason a 2UZ engine blows, then ends up as parts. Is from overheating! Which warps the head allowing coolant into cylinder, then on into crank case (oil). So any used cams w/actuators, are very suspect.

Good luck and hang in there!