Rough start, lacks power

So someone suggested that I swap the injectors, and see if the p0302 is due to a bad injector. So couple of hours later after swapping injectors of cylinder 2 bank 2 with cylinder 1 bank 1, same issus again. The p0302 and rough running occurs on moderate to hard acceleration, but not always, maybe 1 out 4 times of hard acceleration. If in park or neutral, and bouncing of the rev limiter for few seconds doen't invoke the p0302. I also had p0019 since doing a relearn, disconnect battery positive for 5 minutes, re-connect run for 10 minutes AC off, run for 10 minutes AC on, drive slowly for 15 minutes, then moderate to hard acceleration. After I did the relearn, the p0019 popped up straight away on pending, but after I had to clear the codes with p0302 to get the engine to run smooth again, it has not shown up...yet.

So swapped the VVT exhaust solenoids, no remedy, swapped the coils no rememdy, swapped the spark plugs no remedy, swapped the cam sensor with one of the VVT sensors as they are the same no remedy, swapped the injectors on opposite banks no remedy.

 

Have you closely inspected all wiring for rodent damage? I'd do a thorough check of the wiring harness.

 

We rarely have rodent damage here, especially after the hot summer months in Dubai. The heat is too harsh for the critters. Also been looking at the wiring, and all looks good, a little dusty, but good.

 

I haven't read the whole thread, but I had an F-150 do the exact same thing you are describing. I believe the problem was a stuck valve that let fuel into the injectors. It was constantly open.

 

Oh crap.

 

The good news is that it was only a couple hundred dollars to get fixed. But I took it to the shop as soon as I smelled gasoline in the cab. If its been going on a while the injectors could become damaged. I would get it looked at ASAP

 

so in park or neutral no p0302 but you do get P0019? Even if flooring it?

and while driving under heavy load you get P0019 and P0302? And this also gives lack of power?

and you can get p0302 to not trigger if you are driving lightly under 55 mph?

and you also get consistent rough starts?

and you were running 40W oil?

assuming these are all true, given what you have posted, it sounds now like you have a cam phasor issue.

it is likely not the mechanical phasor but the actuator that controls oil flow too the phasor.

problem is figuring out which one?

 

That is not bad at all. Thanks for the pricing.

 

Well just an update, changing the crank sensor has not changed anything. I looked at the VVT solenoids again, this time cleaning them and checking the resistence, about 8.9ohms when cold.

Also did an engine flush, and then changed the oil again with 0w-20 castrol and a new filter. No changes, had a garage look at the codes and run some tests on the VVT system, they said all within spec.

This is really a strange one, as I have been looking at LX570, Landcruiser 200 series 5.7, and even went into 1ur-fe, or the V6 Toyota engines with dual VVT, but the 1ur-FE and the FJ I believe change the cams with motors, and not oil pressure.

 

Can you describe more about what was involved in the tests on the VVT?

I think you have whittled it down to the actuators for the VVT being suspect.

 

The garage must have used the active test for the VVT, that is also available in techstream, which I have also done, when taking the exhaust solenoid of bank 2 to positive on the test, it almost stalls, and misfire counts on Bank 2 cylinders. This I assume is to check if solenoids work and the vvt gear works. The testing procedure asks to check that the angle of displacement changes in the freeze frame data, but I don't see this data anywhere.

 

Ok so given your actions above is there currently any improvement at all? What are the current issues?

 

The only actions I have taken are changing oil to 0w-20, once ran an engine flush before adding the 0w-20. We were thinking the 5w-40 was causing issues with oil not flowing where necessary in the vvt feeds to the solenoids, and ultimately the vane actuators. But no change, it has been 5 days since last oil change with engine flush.

I have changed a crank sensor, as this car only has 1 sensor, so can't swap and move the code to elsewhere to pinpoint fault with component.

I have swapped vvt solenoids, vvt cam sensors, and cam sensor with a vvt sensor since they are the same part. Changed spark plugs, coils and injector on cylinder 2, since cylinder 2 throws a misfire 1 out 4 times on hard to moderate a acceleration above 4500rpm. Misfire then puts the engine into limp mode, and disables vsc, radar cruise control and trailer brake. But all can be reset with scangauge, and a restart to bring the vsc, radar cruise control and trailer brake. But upon start the p0019 shows pending, and and on subsequent start the MIL illuminates, but engine runs smooth. In park or neutral there are no misfires if flooring the throttle, so the misfire only occurs on load.

 

it’s like the exhaust cam is getting “stuck” under load and not allowing vvt system to advance/ retard it.

Or the cam sensor is not getting reliable signal like the teeth on the wheel are damaged.

When did these issues start mileage wise?

Cam sensor, solenoids, crank sensor, vvt system response test are good. New plugs new coil and injector.

man if this were my truck in your situation, I would be prepared to take off cam cover of affected bank. Check for mechanical damage on a cam bearing surface, or a damaged lobe on cam. Also look at teeth of cam trigger wheel for damage or defect.

I’ve seen on another vehicle where a loss of oil pressure damaged cam bearings first.
This totally disrupted the cam
Phasor function and had similar symptoms.

 

Yeah o think the cam cover needs to come off. But I have to give to a independent garage, the truck has just over 10,000miles now. I am I dubai.

 

@ViktorG
Maybe he can help? He is a toyota master tech.

 

Any updates?

 

Hey nothing yet, the oil change has not solved the issue. The engine rocker will be opened to check the chain, vvt filter.

Thanks for checking up on me.

 

So I took the Tundra to the shop, and we had removed all the electrical issues that could occur, even TIS said to check the cam phaser, timing chain, tensioner. So my garage which gets a lot of multibrand vehicles, and mostly Toyotas opened it up and found the hydraulic lifter off the hydraulic adjuster sitting near the intake camshaft. Luckily no detrimental damage, and we are just waiting for the lifter to arrive and also replace the adjuster at the same time.

We suspect some kid of manufacturing defect on the lifter, as there is cracks on it, perhaps you can see them on the photo. The worry is what about the remaining 17!!!! Nut no one else has this issue here, or on any other tundra, Lexus LX570 and Landcruiser 200 5.7 forums, which share the same engine.

Any ideas on what would have caused this, other than metallurgy failure on the part.

 

Wow!! That's pretty crazy, it seems like an anomaly, I did a quick Google search and I found only one instance where this happened to someone else, and another where his broke because its a twin turbo 5.7, ill post the links for you, they may be of some use. I wouldn't worry about it too much. I think once it's fixed it should be just fine. I'd definitely run a little lighter on the oil, I use 5w30.

https://www.tundras.com/threads/two-rocker-arms-off-wtf.50314/

https://forum.ih8mud.com/threads/5-7l-3ur-broken-lifter-lash-adjuster.1150136/

 

I was using 5w-40 full synthetic, as we stay in probably the hotest climate in the world, Dubai, when this occurred. I switched to 0w-20 to see if it was a oil viscosity issue, but the problem of fallen of rocker had already occurred. I am just baffled, the reason I bought the Tundra V8, as I wanted a reliable long term investment, end of engine production from Toyota would be a good choice, over some twin turbo V6 in the hotest climates on earth.....now I dont know!!!!

 

I think you'll be fine in the long run, it's not a common issue at all, and your truck has low miles, so it could have been something overlooked at the factory during engine assembly, a bad part, something not seated properly, etc. Keep us updated on the fix!

 

Someone mentioned that 90% of time that this occurs, the valve is bent? Any techs can confirm that this would be the case.

I am on the fence to have bought a tundra at the moment for obvious reasons, but glad that I did in one way, all the help from you kind folks out there. Pleasure to be here.

 

We have a few @Ruggybuggy @ViktorG are the main ones I know, I'm sure someone else can chime and name a few more to help!

 

I've seen this many many many times in Ford 2v 3v engines. Their lash adjuster (lifter) and rocker arms (follower) are very similar to the 5.7.

I've seen this from a failed lash adjuster that bleeds down and at right conditions the rocker spits out.

Other times it was from valve float in high rpm.

Other times from oil aeration (but there was a lot of other downstream damage which you don't appear to have).

So my questions from reading your post--what is cracked? the lash adjuster or the follower?

 

What Toyota call the "ARM SUB-ASSY, VALVE ROCKER", and the picture of what I have posted as a separate part on the front grill

 

I've never seen this happen before. I wouldn't worry about it once you know what caused the issue. The 5.7l engine is very reliable. You are right that a bent valve you cause the issue. Has the tech remove the valve spring (make sure piston is at top dead center on compression). Measure the length of the protruding valve and compare to another exhaust valve. You can also add a little air in the cylinder (leak down test) and check that the valve is seating. Move the valve in the guide to see if it is binding. Did the motor ever hydraulic lock? Check for a coolant leak in that cylinder if it has. How does the spark plug look? You should have got a misfire code on that cylinder that would have help you diag this problem.

 

if rocker is cracked it’s likely a defect.
I’d replace the lash adjuster and the rocker and carry on with life.

 

This is what we plan, cam has to be removed and we can feel if the valve is binding or not, and do the measurements as mentioned above.

 

Misfires at above 5000rpm once in 4 attempts, not anywhere else. Goes to limp mode, and resets with clearing codes, then runs smooth, only has constant p0019. No coolant leak that is obvious, only 11,000miles from new. Would 5w40 oil do this?

Spark plugs are good, previous posts has picture of the plugs.