Coolant Leak

4 weeks and 1300 miles in, Weds pulled the truck out of garage and saw a small puddle of pink on the floor after being driven 100 miles day before. This morning a few drips just siting for 2 days. Monday before dealer can take a look. I think this is the earliest by at least a year and 15k had to take any vehicle in for warranty work that was not some trivial trim piece or the like.

Not sure Toyota speaks turbo yet. EGRs are the weak link for a lot of turbos. My Ram EcoD had the EGR cooler swapped out twice once due to an issue and 2nd due to recall.

 

These dual turbo motors making 400 HP are a much different breed from the simpler turbos of yester year pre all the emissions complexity. Turbo uses recirculated emissions gases which are cooled and fed thru the EGR system to the turbo. The turbo is not the usual suspect here although Toyos wastewater design seems to be less optimal. The EGR system is the problem child typically and not the turbo itself. EGR is much more complicated for these engines and the small diesels now

 

The reservoir bottle can open up and release coolant if over pressure. Unlikely in this case.

Find where the leak is first before making assumptions of the source.

 

Dealer pulled skid plate and said multiple leaks. Given what was on my garage floor was not pink coolant but chocolate milk I am guessing multiple fluids most likely oil and coolant.

Dealer said give them 2 days to figure out how to fix the big green lemon. I opened case with Toyo and looped the GM at the selling dealership I would be coming in hot if there is significant work to be done.

I think I may have made a big mistake trading in my truck that had one sensor failure in 6 years for this Toyota science project

 

Not sure these have EGR's. The 3.5 Ecoboosts did not have them until 2021 so its entirely possibly the iForce doesnt have one.

Also, the function of the EGR on a gasoline engine is completely different than the function on a diesel. Diesels use them almost all the time to suppress cylinder temperatures to minimize NOx.

 

They are water cooled turbos where I assume the water is circulated coolant? If so that is similar to the diesel that the coolant system is integral to the turbo operation although may not perform the EGR function as with diesels.

My experience has been the coolant circulation part of turbos is more complexity and issues can risk both the turbos or the engine.

 

Thats not what an EGR does.

On a diesel, EGR feeds pre-turbo exhaust gasses back to the intake to reduce the amount of oxygen in the air charge going into the cylinders. This makes the engine run richer because the exhaust gas is displacing what would be clean air, reducing cylinder temperatures, and reducing the formation of NOx.

Some of the newest diesels, like the 3rd gen EcoDiesel and 3.0 Duramax also have a low pressure EGR which pulls exhaust from after the DPF. This means the exhaust is cooler and has significantly less soot than the pre-turbo exhaust.

On a gasoline engine, my understanding is that the EGR's only serve to act as a way to reduce pumping losses at low load. Since a gas engine has to throttle air to reduce power, when you are at low load, the throttle plate is mostly closed causing a lot of vacuum inside of the intake manifold. The pistons have to pull against that vacuum which hurts MPG's. The EGR reduces the amount of vacuum by filling the manifold with inert exhaust gas. So you reduce the vacuum without increasing the amount of oxygen so MPG's improve.

 

I understood the diesel EGR function per my original post.

Admittedly don't understand the water cooled part of a gas engine. There is a coolant part of the gas turbo system otherwise heat dispersal would be catastrophic to the turbos. My hypothesis is that involved cooling lines from the main coolant system. So like the diesel EGR the gas turbo cooler and cooling system are co-dependent.

Either way my new Tundra is not working or built to design. It is a late 2022 model year build. So the gremlins are not fixed 1 year into production.

 

That's what they should have put in these trucks. Could have used that engine and tuned it up a little.

 

Yes the turbos are water cooled and that could certainly be a leak point. But that has nothing to do with the EGR

 

The EGR and Turbos are two separate entities. They two do not interact other than the EGR will take exhaust gas that would otherwise flow through the turbo and recirculates it back to the intake manifold. This is true for both diesel and gasoline engines. The EGR is just a bypass off of the exhaust before the turbo, and the cooler is there to cool that 1200+ degree exhaust gas before it is sent into the intake.



That said, both the EGR and turbo could be coolant leak points. I just don't know if this engine has an EGR or not. It very likely doesnt because they can do similar things with the variable valve timing.

 

I can't speak to whether or not it has an EGR. What I can say is that the V35A-FTS that is in the 2022 Tundra has 2 separate cooling systems. It has the traditional cooling system for the engine itself, like in any other car. It also has a completely separate cooling loop, which includes it's own electric water pump, for the turbo system. This separate cooling loop comprises the intercooler, turbos, and turbo/intercooler radiators. It does not involve cooling lines from the main coolant system.

 

Final talked with service director. The leak was on the regular cooling system side and not the turbo cooling path. Replacing the expansion tank and a rod and a hose. He said the rod was the really iffy looking part and the others were more just in case replacements. Said the rod would never pass a visual inspection

Appears to be a case of quality control issue as Toyota sources all these parts to make this new engine. Hopefully this is only one for my truck