Check Your 3.5l Coolant Pipe!

It's possible that they did update/fix as the part number for the plastic piece has been superseded from 16356-31050 to 16356-31051. I do not know what production date saw the change, or if the change is to deal with the crack. However, it's reasonable to say that there are many of the older style on the road, and they will eventually give it up. This higher performance aluminum version wouldn't exist at all if plastic was the end all be all.

 

Here's another one. 2017 - 42k miles. Spotted coolant drips at the rear of the engine. Dealer replaced it but not under warranty. They claimed it was the first one they had seen, suggested opening a case with Toyota. Said it was "worth a try". Replaced with Part #16356-31051. Photo shows the area of the leak, right at the seam.

 

Here is the non-leaking unit from my 2019. No idea if it's the updated piece.

Production date.


Manufactured by NTCL/Nippon Thermostat Co. Ltd. Longtime Toyota Supplier. Material is PA9T GF35.

 

Did they mention if the new one was metal or not?

 

New units are plastic.

 

Thank you.

 

I had no heat last winter unless the engine rpm was above 2500. I suspected air in the heater, probably from a cracked bypass pipe even though there did not seem to be much coolant loss, but I did not try to inspect the pipe. This winter I put two bottles of Subaru cooling system conditioner in the radiator (this is actually a leak sealer). So far the heat is working normally again. I still have not inspected the bypass pipe but I obviously had a small coolant leak somewhere. My truck is a 2017 and is beyond the initial warranty period. I do not want to pay for a pipe replacement unless I have too, I am hoping the leak sealer works or Toyota issues a recall.

 

Plastic. They did say the old part number has been superseded by a new part number but did not know if the part had been changed in any way.

 

Why did they not replace it under warranty? Was it not included under the powertrain warranty? I have a 2017 with 33k miles...purchased end of summer 2016, so I still have some time left under my power train warranty and may have that issue too. I'm taking mine into the dealer on Monday. I spotted a very small drop of coolant on my garage floor the other day, but it is not a continuous drip.

 

My truck is still under the Power Train warranty as well. Dealer claimed that they double checked and actually said they would "much rather bill Toyota than bill me, however, the cooling system is not covered under the Power Train warranty". My argument was that it was essentially part of the engine, but that didn't go anywhere. About all they suggested was opening a case / complaint with Toyota, which I'm in the process of doing. We'll see what happens.

 

oh godamnit.

 

What did they charge you ?
Wonder if it would be covered under an extended warranty in any manner ?

I have no problem using plastic in outlet pipes but when you bridge two metal parts that can move slightly with a rigid piece of plastic you have an issue. Design 101.

 

Just under $1,200 for the repair.

After opening a case with Toyota and a lot of back and forth phone calls, they paid $500...
I asked if they had a formula for determining this kind of payment but didn't get a straight answer.

Better than nothing, but it sure didn't blow my skirt up.

 

Hopefully this part will be changed to a metal one as well. I have a 2015 DCSB TRD O/R 4WD Auto & I'm sorta waiting for the last year of the 3rd gen (2022? 2023?) to be produced & I plan to buy a new TRD O/R then. Problem is as much as I want to like the 3rd Gen I seem to always find "one more issue" with them. Of course, this is a forum where most of our posts are regarding complaints & issues. Hopefully you folks can get your issues resolved. I tell you this. I WILL buy an extended warranty when the time comes

 

From reading this thread at the beginning my determination is 2016 & 2017 tacos are the ones affected my 2018 is bone dry and plastic with 58000 miles

 

IMO no plastic piece will last forever. There needs to be a transition piece that can allow some movement, such as a rubber hose, between two solid pieces of metal that are moving due to temp changes, vibration etc.
2016 and 17 are a little older than your truck, so give it time and get back with us.
Same design, same material, same problem area.

 

Agreed the thermal expansion & contraction of the aluminum engine itself is reason enough to know a hard plastic component stretched across two cylinder heads WILL fail. I'm hoping the tube has enough 'slop' in the mounting holes with a steel bushings, plus hopefully a viton O ring it's allowed/designed to move around some.

So far with 60K on mine & no sign whatsoever of leakage or reservoir level decreasing mines going to survive this stupid ass design......gezzuz TOYOTA I know your smarter than that..........or was it made to fail causing engine overheating/ failure so they can sell more trucks due to the fact if properly maintained they NEVER die?

 

Same symptoms I had....luckily they covered mine under warranty

 

Heat-Resistant Polyamide Resin, 35% Glass Fiber reinforced.

Damn you AvE, for teaching me this.

 

Basicly a piece of shit accountant caused part