Arsenii

Hello,

In famous words of one famous detective - "Unraveling crimes for all my life and not to learn to cover my own tracks".. This is how I would describe the utter misery of diagnosing VVT solenoid failure in my own 2000 ES300. This won't be written in my usual fashion, I basically just threw all my thoughts out there, some of them completely unrelated, maybe there is someone out there who will find it useful..

It all started pretty calm, one day the car surged a bit in a corner, it felt as if I drove into a pothole that I didn't see, so I didn't think much of it. But then a few weeks later it happened again, and then again in a few days, up until one day when the car barely stalled right after I pulled into a driveway at home, throwing a P1349 code along with plethora of pending Misfire codes. Before we proceed, let's admire the dependability of the car that got me home safely, and only then starting to stall out, this could've happened in the middle of the road with far bigger consequences.

In any case, now it was pretty clear that there is an issue to be diagnosed. Like any lazy person the first thing I assumed was that the solenoid failed and needed a replacement, so to test it, I pulled it out and connected it to the battery to see if it works at all, and to my dismay, it was working perfectly. So I put it back in the car, and took out the Techstream cable to see if I could operate the Solenoid through it, and wouldn't you know it, Bank 1 had no reaction whatsoever, while Bank 2 nearly stalled the car, so I knew that Techstream worked.



For the next step I decided to connect the Solenoid straight to the battery using some spare wires while the engine was running to see if the issue is somewhere deep in the pits of the engine, or the ECU is not sending the signal. Interestingly, the Solenoid operated as expected, the engine did react to it, so I knew that the issue had to be somewhere either in the ECU itself, or the wiring from the ECU to the Solenoid.



Before digging into the wiring, I figured I would pay a visit to the ECU, as it was a lot easier, so I took it out and apart to see if there is anything suspicious there, but after tracing the routes from the connector to the transistor that controls it, I didn't see anything suspicious. In any case, I had a spare ECU out of a 2001 model with a key laying around, so I decided to give it a try. While the issue was still present, it did solve a few other issues that I never knew were caused by an ECU, like the flickering lights at idle, they are still flickering a bit, but not as bad as they used to, much to my delight.

Turns out that A/F sensor Heater circuit is not just connected straight to the battery, it's connected through the ECU and is powered by a 2Hz PWM output, such that the ECU can precisely control the temperature of the sensor, but as a result, the load on the Electrical system also fluctuates along with the PWM output, the heater circuit of each sensor can draw upwards of 3 amps, causing the lights to dim and flicker. Not sure what exactly changed with the upgraded ECU, maybe they increased the PWM frequency, maybe the assembly that provides the PWM output is in better shape, or it could just be a sheer luck.. Any ideas are welcome!

In any case, I was still back where I started, the car won't run stably, and all that's left is the wiring. To test the wiring without pulling the intake off, I got some very long leads for a multimeter, connecting one to the ECU, and the other to the wiring under the hood, then started wiggling, twisting, prying every wire I could reach in an effort to break contact, but the wiring appeared to be intact, it hasn't lost a beat, and I can still hear a multimeter ringing in my head.

Having exhausted all other options, there wasn't much left at this point other than to start digging into the engine, the thing I was trying to avoid the most. It took me about 2 hours to take the rear valve cover off, luckily for me, and to a big credit for engineers who designed this engine, you don't have to mess with the Timing Belt to access the VVT gear, the belt drives the other camshaft, so it didn't take much time to remove the VVT camshaft for an inspection.

One important note, do not forget to put in an M6 Bolt that will hold the two halves of the Slit gear together when you take the camshaft out. This gear is spring loaded and is designed to reduce noise when the gears mesh, if you forget about it, it will be a nightmare to align again, ask me how I know..


After taking valve cover off, it should've raise a suspicion that I am doing something wrong, the engine looks relatively clean for the age.

To test the gear itself, start by checking if there is any backlash in the gear from the camshaft, there is a Spring Detent that holds the gear in place when VVT gear is not used, if the Detent is worn out, which is a common problem for VVT-i engines, it causes quite a bit of rattle on a cold start. Since you already made it this far, may as well replace the camshaft assembly if there is any backlash in it.


Next step would be to check if the gear can turn at all. Cover all the oil ports aside from one farthest from the gear, I used electrical tape and then made a hole in it for one of the oil ports, that is what you will use to blow compressed air into. Be prepared, it will NOT be pretty, as the VVT gear is still full of oil, so you will need to put a towel on your work bench and in close vicinity of the gear, as otherwise it will be a nightmare to clean up.

What compressed air does is pushes the Detent out of the way, allowing you to turn the Gear separately from the camshaft. With that, the ports are still covered, the remaining oil in the gear won't let you turn it much from this point, so you will have to remove the tape while holding the gear to prevent the Detent from latching again.


Blow the air just in one port, you will have to cover all the other ones if you want to avoid at least some part of the mess.

I am pretty sure you already guessed where this is going, the VVT gear is completely fine, not a hint of any wear or damage, even the detent is still quite solid with no backlash, the gear does turn nice and smooth throughout the full range, so I basically wasted an entire day fighting windmills..

At least something good came out of it, I finally got a Valve Cover out of 3MZ-FE engine with upgraded PCV valve and oil buffer, this was one of the more common reasons for sludge buildup back in the day, and the PCV valve with the grommet always drove me nuts, especially if you compare the prices for the old and new designs. In any case, if it is something that tickles your fancy, I can verify that 3MZ covers can be used on 1MZ.



Other problem I ran into is that after about 4 years of service, Fel-Pro gaskets gave out and started leaking again, even the Spark Plug tubes, not sure if it was my fault or a bad design from the factory, in any case, I decided to give Mahle a try this time, we'll see how they hold up.

I also tried replacing the Washers for each Valve Cover bolt, someone said a while back that they were a single-time use, but I couldn't figure out how to pull them past the knurling designed to keep them in place without damage, so about $40 later, I am left with a nice souvenir of 20 washers that no one in their right mind will ever need, maybe a good weight for fishing I suppose..

Looking in the manual, there is not a word about those washers either, had I looked into it before making a purchase, would not have done such bonehead move, I just ended up using the bolts that I got with a new valve cover, they are in much better shape than mines. I also compared the thickness of the old and new washers, it is pretty much identical. So for everyone who still believes that they need to put extra washers under those bolts and then use a torque wrench to "attempt" to tighten them evenly, I would really suggest to rethink this practice.


That's about as far as I managed to get it before crushing it.

Though I think we got distracted from the main passage, so it's about time to get back on track. Now all the possibilities are exhausted - VVT gear taken out and verified working, I also checked that the oil passages from the Solenoid to the Gear are clean, ECU replaced, Wiring tested, Solenoid .... hmm, let's go back and revisit it for a second..

While it was the first thing I checked, this was the only other component that could cause something like that, as the car kept surging, VVT readout on scan tool kept turning On and Off with each surge. And this is where it dawned on me - the problem would only appear when the car is fully warmed.

This is where I made one small test - I threw the solenoid in the toaster oven set to about 350°F, waited a few minutes. After taking it out, the solenoid froze completely, no movement, and barely any sparks coming from the wire, as if the coil got cooked and lost contact. After letting it cool for a minute, as if by magic, it sprung back to life like nothing happened, and this is where the puzzle came together.




I knew that solenoids do fail with heat, I've had that experience before, but I never managed to connect the dots and think about it until after exhausting literally ALL the other options, basically throwing about 2 days of my life down the drain. In any case, all is well that ends well, now I have new valve cover gaskets, I verified that mechanically, the engine is pretty sound, especially for it mileage, and now I have an upgraded valve cover that should make servicing the PCV system a lot easier, I shall see if it will make any difference in the future. Currently waiting for a new OEM one to arrive before I melt the old one into oblivion and scatter its remains somewhere over Great Lakes, luckily they are not too expensive..

If there is anything at all that you take from it, let it be this - always stay calm and THINK before you do something. In my case, I jumped straight at it, without stopping to consider other options, this was very much preventable, only if I thought about it just a little longer.



Hope this helps someone, and best of luck! Don't make the same mistakes, learn from them.

LeX2K

Excellent write up my friend, your pain will end up helping others. I can say for certain Fail-Prone sorry Fel-Pro products are inferior they are no better than the generic made in China stuff out there. Which is exactly what they are. A machine shop I use tells me Mahle makes good gaskets they use them at the shop when OEM is not available or too expensive. That's some nice detective work baking the solenoids haven't thought of that, but when in doubt I simply replace them. I do add washers and tighten by feel, otherwise some of the bolts bottom out before they are putting enough pressure on the valve cover. Speaking of, I have a 2002 ES300 one sitting in storage that will eventually go on my car.

I've mentioned this before, for the rear bank I RTV the entire surface of the head along with a new gasket. Heresy in some circles but it works, no more leaks.

Be glad you are not dealing with 2GR VVTi cam advancers those things can end up being a nightmare to the point where the engine may as well be scrapped. Not common but it does happen, so for people that have VVTi rattle at start use the best motor oil you can afford it helps.

I once replaced all the rod bearings in a 2VZ-FE chasing down engine tick, it didn't work. I even replaced the crank woodruff key out of desperation. Problem ended up going away on its own I never knew what caused it. I spent so much time and money on that project for nothing lol.

....on those washers they are are put on the bolt before the machine knurls them. Similar to normal style captive washers they are put on a bolt before the threads are cut.

FromFL

It may be inconsequential, but that seems to be a lot of varnish (same for my '04). These motors for some reason seem to "like" varnish.

Anyway, I have a Honda with the occasional VTC rattle and I absolutely hate when I hear it, and at just 60K miles, it's very disappointing. On my ES, it'll sit for weeks and never a hint of rattling at start-up.

Arsenii

Those Fel-Pro gaskets have a history behind them, that was the time when I learned the intricacies of buying "OEM" parts from eBay, with those gaskets not lasting a day without leaking, so pretty much everything was better than what I got initially.

Mahle is an OEM manufacturer for BMW I think, not like it makes them particularly honorable, but I think it has more to do with the inherent temperature management issues with those crammed engine bays rather than the quality of seals.

Weird, never had that problem before.. But I did get fed up with Toyota's older design that used those Rubber washers and no limiters, like on UZ engines, so you really had to tighten them by feel, and it never worked quite right.

I only go around the bends and edges, it's a real pain to clean up while the engine is in the car.

I had to deal with 2GR a few times, the engine in a vacuum is great, but I'll be darned to work on it again. The way it is crammed in cars that didn't really need it (Camry and RAV4), every single bolt ended up being long enough to jam against the frame rail, at times it felt as if those bolts go all the way across the engine and tie it to the transmission. It feels like with LR Discovery at times, where you first pull the cabin off, and only then proceed to change the oil.

Yep, I knew that, but with the company that refuses to sell rubber mounts on an intake box citing that they are too hard to remove, I wasn't expecting those washers to have a separate Part Number if they are not designed to be removed.

Any engine will develop it with more than 230,000 miles that I have on it, it's just a natural process of the oil breaking down with temperature. Higher quality oil and more frequent changes help with it, but don't mitigate the problem completely. With that, it's not like the varnish itself affect the performance, it mostly just gives a tint to the parts, it's the soft sludge that is more concerning, as it can cause a lot more damage.

Huh, rattle at 60,000 miles, interesting. I wonder what's the service history of the car, maybe try following LeX2K advice of using the highest quality oil, like Amsoil to see if it will help at all.

lexo98

iTrader: (2)

On my 2nd Gen GS I had been going long intervals between oil changes since my rear main seal was leaking and I was having to add new oil. When I got the 1349 code I cleaned out the VVTI filter and changed the oil. Not too long after the code came back. This time I had some sludge in the VVTI filter. After I cleaned it out and changed the oil again the problem never reoccurred.

Arsenii

As far as I am aware the fact that your oil leaks out doesn't exempt you from a full oil change in the same interval, as there is still plenty of old oil being diluted with the new one, reducing its properties, hence why you may be running into the sludge problems that you have.

lexo98

iTrader: (2)

Sludge problems I had. All issues were corrected. Car has been parked for a few years now. I was neglecting the oil changes with hopes of blowing the engine and doing a turbo swap but that engine was bullet proof.