Help: 01 misfiring and heating up, replaced motor, same problem

Ok, so get ready for a doozie of a story. I'll try to keep it short.

My truck: 02 4.7l Tundra, AC 4x4, 220k miles.
Purchased truck at 200k miles. It was a one owner ranch truck. I see it had some service records and had a timing belt/water pump done at 170k so I felt ok dropping $3500 for the truck. It was DIRTY and that was an understatement. It may have never been washed or vacuumed. Whatever, I needed a truck and had to buy one that day. It was this or a 12v cummins for $5k. Sometimes I wish I went for the diesel but know it could also be a can of worms, but I digress.

I use the truck for towing 18-23ft. power boat up at higher elevations (~7000k ft). It does the job well and I don't tow for longer than 10 minutes. Never noticed any issues.

I let a friend borrow the truck. Someone I thought I could trust. He didn't tell me he towed a 6000lb boat and trailer up a big mountain pass. After that I noticed the truck started spewing white smoke after engine braking and getting back on the throttle. Did tons of research on what it could be and started throwing parts at it like an idiot. Summer season is ramping up and I can't stop work and the truck still ran well minus the puff of smoke so I kept going. After a few weeks it starts having lack of power and more smoke. Smoke isn't sweet smelling. Not blue. Not dark or gassy smelling. I couldn't figure out what it was. My fluid levels never changed. Then it got much worse. It started losing power and mpg became worse. I have a monitor to watch engine and tranny temps and notice that engine temps are now getting above 188F when climbing hills. Now here are the major symptoms of this story. The truck will shudder when getting on the throttle and have almost no power. CEL flashes and the coolant temp rises. The pending code I get is either a PO304 or PO300. I tried using all kinds of snake oil, sea foam everywhere, new plugs, swapping coils to move the CEL, different fuel, new fuel filter, battery, air filter, exhaust manifolds and nothing fixed the issues.

Finally realized I can't drive anymore. Park the truck. Have to buy another truck to finish season. I drop truck off with mechanic. They determine that I have a blown head gasket and fried cylinder 2 and 4 after a leakdown test. They don't have the time to do a motor swap or rebuild.

I purchase an 02 motor from a dismantler. It has 116k miles. I replace the water pump, timing belt, and every seal you can get to while the motor is out. After what seems like an eternity of hell I finally get the motor replaced. Two things of note, the new motor harness was 2wd and my truck is 4x4 so I had to reuse my old harness. That involved taking apart the intake manifold to replace. While in there I replaced the intake manifold gaskets. Couldn't get OEM so did FelPro. As I go to start it up for the first time it won't turn over. No sound from the starter. What the hell. Check all the wiring and narrow it down to the starter wiring. I pop off the intake manifold again and see the plug on the starter had popped off. Plug it back in and go to reassemble the manifold and being the ray of lucky sunshine that I am wrecked one of my new gaskets (passenger side). I inspect the old one and determine it is probably alright and drop it back in. Bolt everything up and go to start the truck. Fires right up and purrs. Sounds great. Button more things up and take it for a drive. Drives fine for a bit but I notice after a few miles the temp goes up to 190 whereas the old motor topped out at 188 when healthy. Ok, no problem. After some research it's within reasonable spec. I drive it some more and lo and behold my old symptoms start to arise. Lack of power, temp start rising, shuddering, and a rattling noise under throttle. There is also somewhat of a whistle or squealing noise when under throttle or revving in neutral. I will try to upload a video link. When I get on it the power is gone. I wont' accelerate, ever in second gear at 4k rpm. The temp will approach 200F. I'm sure it will continue up but goes back down when I get off it. I continue to get flashing CEL with a pending PO300 or PO304. What the hell, I just replaced the entire motor and i'm having the exact same symptoms minus the white smoke.

So i'm suspecting this might be a toasted passenger side intake manifold gasket. The only things I retained from the old motor are the harness and the passenger side intake manifold gasket. The symptoms seem plausible to be either of these. The PO304 code is from the passenger side of the engine. Tomorrow i'm picking up new OEM intake manifold gaskets and will see if that helps but i'm at such a loss after the incredible epic this swap has been that I need help. I'm posting here to see if anyone has any idea what is going on or something I can try. I really need to get this thing running before I run out of money and the snow flies.

Ideas? Thoughts? Any help appreciated.

Thanks

 

Youtube link to video showing an attempt to WOT accelerate. I think this was in second gear. Super sluggish, shuddering, and noise. You can see the temp rising, refusal to get up and go, flashing CEL, and rising temperature. Sometime you get on it and it behaves normally but more often that not, this happens. Especially on the highway.

https://youtu.be/meGXbWLB8ec

 

have you considered the issue is the ECM?? I know the 1UZ on the Lexus SC400/LS400/GS400 had issues with capacitors going bad and causing all kinds of issues... I would suggest contacting Tanin Electronix and asking them about your issues, as they sounds sorta similar..... if you feel brave pull the ECM and crack it open..

 

Ya, it's possible. It's still the original one, afterall. I have an appt with my mechanic but i'd prefer not to spend a bunch of money on a goose chase.

If the manifold gasket doesn't solve the problem i'll be giving Tanin a call. Thanks for the advice.

 

Is it going lean and misfiring? How's the A/F ratios look?

You could try swapping the #4 injector with a different cylinder and see if the misfire follows it.

 

https://www.tundras.com/threads/multiple-cylinder-misfire-p0300-301-304-305-308.37269/

This guy had some similar symptoms, bad gas. Sounds like you've gone way beyond that. Are the injectors the same ones from the original engine? or from the 116k engine?

 

Unfortunately I don't have a way to read A/F at this time. I can see what I can find. The injectors are all different. It would be quite the coincidence that the new motor's injectors are creating the same PO304 code. I'll definitely try that tomorrow after I swap gaskets.

 

I saw that thread. I was super suspect of bad gas especially since our Chevron had run out of gas a few days prior to the new bad symptoms occurring.

Injectors are from the 116k motor. Just seems odd that both motors threw the PO304/300 only.

I'm suspecting that the overheat incident where my friend towed with my truck toasted the gasket in such a way that it's causing problems in the cylinder 2/4 group.

 

That video sounds horrible. Don't drive on a flashing CEL, that signals a harmful condition that could ruin the engine. Definitely sounds like it's misfiring.

 

Ya, it's parked. Wanted to get a video. Correct me if i'm wrong but the flashing signifies a misfire, specifically. CEL flashes, then a pending code for a misfire appears in the pending menu, not the saved code menu.

 

Also of note, the MAF sensor is still the original. I cleaned and inspected it. I'd imagine that would cause more than just a cylinder 4 misfire.

The odd thing is it's somewhat intermittent. Sometimes the truck sounds great and runs well. Idle is perfect. Fires right up everytime. It's only under load.

 

Tundra Check Engine Light Flashing Due to Ignition Issues
The ignition system is the most common reason that the check engine light will flash. The ignition system consists of spark plugs, plug wires, and the ignition coil packs (older vehicles have a distributer that has the same function as coil packs). These parts work in concert to ignite the fuel in the combustion chamber at just the right time.

• P0300: Random Multiple Misfire– This is one of the most common codes that is thrown when the engine is misfiring. It means that the engine has a misfire, but the computer can’t detect which cylinder that it’s coming from. This code is often thrown when there is a fuel issue, or a timing issue, and not just bad ignition components. That is unless all the cylinders share a common coil (distributor ignition).
• P0301-P0312: Cylinder Specific Misfire- These trouble codes correspond with a specific cylinder misfiring (cylinder number corresponds with its place in the firing order). Although it’s a bad sign when the service engine soon light flashes, when one of these codes comes up with it (and nothing else), it’s almost always one spark plug or ignition coil. There can be other reasons this code is thrown, you can see more by clicking on the P0301 link above.

 

You can also swap the #4 coil to another cylinder.

 

I've gone down most of the list. No vacuum leaks. New coils, new plugs, different injectors, different cam and knock sensors. If I can rule out manifold gasket and MAF then maybe start looking into harness damage or ECU. The cats are still original (220k miles) but do you think that would cause that? Truck passed smog recently but has thrown a bank 2 downstream O2 sensor code once in a blue moon.

 

Did this. No Change. Then changed the motor. Tried a few different coils and a new coil. New plugs. Cylinder 4 plug looks fine. No weird colors or wear. Mechanic said the original motor was toast on cylinders 2 and 4 while exhibiting same symptoms. New motor, coils, and plugs and same symptoms.

 

During the white smoke escapades, if you were dumping excess fuel in the cylinder with engine 1, it could have damaged the cats. Usually the exhaust will sound muffled under load if the cats have started breaking down and clogging themselves. You'll get a weird sulfery exhaust smell and increased engine temps.

 

I’ve had a fuel pump act this way when it was failing.

 

Big time misfire, so big, the ECU is telling you desperately to lay off the throttle because so much unburnt fuel is making it back to the cats. If the ECU could talk, it would be Screaming.

You've done alot of things, I way either ECU and or cats are suspect. Luck.

 

FIXED!!!!

Turns out the lower intake manifold gasket was damaged. That explains the bank 2-specific misfires. Due to a time-crunch I bought the FelPro intake manifold gaskets because it was available. I do not recommend these. They are soft and papery and very easy to damage on install. The adage of going all OEM Toyota stands true. I installed the OEM ones with no problem and the misfire was eliminated. That is a huge relief.

I am still having trouble with the temp rising. The weird thing is it increases when I left off the throttle but when I get on the throttle it goes down. No problems at idle. The radiator and hoses are all original. The waterpump is new but the thermostat is old. I'm going to replace the thermostat, next and purp the system a little more.

Thanks for all the input, everyone.

 

Definitely looked into the fuel as a possibility because I wasn't losing oil or coolant and it didn't smell sweet or look blue. The symptoms were all over the place. A little this and that made it hard to pin point or eliminate much but seems like a true case of multi-system failure. However, later I noticed oil burning. Not sure but I think the two fried cylinders eventually started letting oil past the rings.

 

Did it have the same symptoms? My truck had so much going on that it seemed like it could have been anything but never had all the symptoms of one thing. But it did have all the symptoms of a bad intake manifold. Just took forever to get to something so simple. When the head gasket went the manifold gasket probably got so hot it failed. The fel pro ones suck.