Rod knocking after pulling trailer up steep hill

IMO: Heat does that. Something doesn't add up because the OP states it never over-heated..... and I believe him. Police cars end up like that: Regular oil changes and/but a lifetime of instant high-speed chases followed by hours of idling waiting for the rest of the Calvary to show up. Stir in some generic bulk-oil no-name-brand oil changes and there you go. The most intriguing thing is that none of the surfaces shown in the pictures come anywhere near looking alike. They all look like they came from completely different engines.

 

whats a OEM short block cost?? I would get the shorty and get the heads looked at by a professional and weigh that cost over the used engine. I wouldnt waste anymore time on that current block. And whats with the dirt yard teardown ??

 

New engine is around 11K, don't know what a long block is. The dirt yard is what you do when your shop is full and you pull the engine outside under a canopy before rolling it in the shop later.

The brown film is the big question. I've run Mobil 1 in all kinds of vehicles with 2 and 4 wheels, never seen it do that. But that's what Toyota said they were putting in it each time they did and oil change <shrugs>. I still don't see abnormal wear on any important bearing surfaces, so hoping to find the issue on the crank/rod bearings, but clearly it was an oil failure.

I think we should have the crank out tomorrow. Fired up the giant parts washer basin thing to start getting the crud off stuff, but wanted to capture pictures first.

Very interested in what the combustion chambers look like once we pull the heads.

 

best of luck to you!

 

there is a 23 v-6 for sale in the classifieds.
Somebody is doing a swap. I think he was asking $6k or so

 

I'm sorry this happened to your truck OP, but I am thoroughly enjoying watching you tear this motor down. I consider myself a decent shade tree mechanic, but I never got to the level where I was comfortable doing what you are attempting.

Mazel Tov brother!!!

 

One thing I havnt seen really recommend.. Remove each Cam Bearing Cap to check for scoring!


I see motors in this condition a few times a year, and they always have catastrophic failures.

A V10 ..


Cam Bearing and Cap scored..




3.5L Ecoboost

 

There are other causes of this... poor oil quality with poor additive packages. ( detergent additive specifically ) or lack of oil changes causing the additives to be depleted.

Other causes can be excessive moisture or coolant contamination. Excessive idling can cause moisture problems.

 

Mobil1 didn't do this: not at 5,000 mi OCLs, not at 7,500 mi OCLs and not at 10,000 OCLs either. Start taking all of your trucks to Jiffy Lube or equiv for an oil change.

 

Not that crazy..

 

This engine wants to be at 3800-4600RPM. You can literally feel it. It's hamstrung from the factory to meet EPA regs and no one is ever going to say that. The fact that the manual gets 1mpg worse than the automatic is evidence. If you tune an automatic, you end up with the same weird gap around 5mph between 1st and 2nd, where the truck doesn't want to take first, but you know it's gonna lug bad in 2nd. If you simply never use the torque of the motor, MPG improves. If I'm Toyota and hurting to meet the limit for the vehicle class... Really you're lucky that gap isn't even longer.

Modern cars sacrifice drivability, safety, and logic in order to meet EPA regs, and to support banking and big tech in America by mandating increasingly-complex electronics in every facet of the vehicle for arbitrary reasons.

 

This dude clearly drives dirt roads and uses his truck for truck stuff more than 99%+ of this forum. Sounds like it's basically a farm truck.

 

You are absolutely correct, but from my 101,000kms + and 6 plus years of experience with this truck, heat is not an issue with this engine. I have never had a engine that shed heat like this one. I park it after a long drive and it cools down and needs to warm up again after only a few minutes. To warm it up on a cool morning it takes 5kms or more of driving...
This engine acts more like a diesel engine than a gas engine with heat. It needs to be worked and will start cooling down when idling. There are several threads on here of people complaining the engine puts out very little heat in sub zero temperatures.

I don't see heat being the cause from my experience. But I am going from OP's description and pictures.

 

-36*c right now with no windchill and I can concur than you either need to drive slow in a low gear or drive harder for it to warm up. Idle for more than a 10-15 minutes, kill the engine for 15 minutes or drive down a long hill and the temperature will start to drop.

Putting the temperature on HI for the grid heater to turn on helps a bunch but it's hard to break my old habit of not cranking the heat right away.

Either way this failure is caused by inadequate oil. Someone should go undercover boss to see what oil they're really using at that dealer

 

What is the cost of buying new parts, time involved reinstalling and hoping that you caught everything wrong? I would be interested in seeing that break down (no pun intended). If you can take a weekend and install a known used good engine with less miles, time wise that has value and a higher potential for longer term reliability.

 

Did not read all 11 pages but, remember https://www.tacomaworld.com/threads/upgraded-bypass-pipe-solution-for-coolant-leak.821061/

 

From some digging around on the interwebs, it seems that varnish is usually formed by unburned fuel when running under load. It sounds like this truck worked hard, so that kind of makes sense. Still, with 5K oil AND filter changes and a decent oil, it probably shouldn't look this bad or have that sludge on the top surfaces. While it's easy to notice whether they are actually doing the oil when sitting in the truck, you can't really see if they are doing the filter. I suspect a combination of low quality oil, a clogged oil filter at times, and how the truck was used caused the varnish and sludge. Using cheap non-detergent gas may also be a contributing factor, but not sure what was being used there.

This is all just internet speculation, but interested to watch this unfold.

 

i think you are correct. toyota recommends changing the oil at 5K when the truck is used this way.

 

@MonkeyProof

Is it usually an oil failure? Assuming we check crank bearing surfaces and bores (and maybe cam bearings), is there anything else that would make it fail again we're missing?