Ask the Toyota mechanic!

Question:
2019 limited bought used, have limited time on warranty/ ability to return truck to car max or decide to keep.

Engine Temp gauge very intermittently drops to zero and stays there.
Once it would not come up from cold at all.
Once it dropped in the middle of a long drive and stayed down.
My question is have y’all seen this?
How bad can it be if it isn’t just the sensor? Should I get sensor changed and not worry?
Thank you in advance.

 

Wheel bearings sound more like a heavy lug tire going down the road. It's a constant growl that gets louder with speed. Swerving the truck left and right reduces the noise and the weight is lifted off. You still need to check the strut bushings.

 

Have you checked the coolant level? Make sure to check it in the rad when cold and not just the overflow bottle. Diag before changing parts. Techstream would be used to diag. If you don't have Techstream you could change the coolant temp sensor on a guess.

 

Honestly the noise is not loud enough where I can test it out that well, I usually can only hear it if there is a surface to the right of the truck. With the windows up there’s no chance to hear it. That’s why I’ve had a hard time diagnosing this.

 

You could wait. The noise will get louder after some time

 

That’s probably the route I’ll take and if it gets fixed when doing maintenance then cool, if I come across someone who know the issue that would be awesome. It’s driving me crazy

 

Should have asked you before I pulled the trigger: Most - but not all - folks recommend carrier bearing spacers for even the smallest rear-end lift. I recently added Coachbuilder +1 shackles, which come with a smidge less than 1" lift. I didn't get any vibration or complaints from the drive shaft after the lift; but I want to keep dimensions optimal. I've ordered the Coachbuilder carrier bearing drop kit for 0 - 2" lift. Is it unadvisable for any reason?

I did plenty of research on the diff drop, and decided to forego that for the 2.25" setting on the Falcon levelling kit. I have ~130lbs additional weight under the front end with 3/8" skid and cat plates, so the 2.25" accommodates a little sag. Confirmation I'm fine there would be greatly appreciated.

Thanks for being here and doing this.

 

I have, coolant in radiator as well as over flow is good.
My concern is that if it’s the instrument
Cluster how costly or shitty that can be.

 

That's why diag is important. With Techstream you can check the gauge operation. Most likely the sensor if your the "feeling lucky" kind of guy.

 

If your not feeling any vibrations I would personally leave it. Vibration occur when you lift because you change the angle of the U joint. The two U joints have to have the exact same angle. If the angles differ the speed of the driveshaft differs on the output which results in a vibration. If you add the center drop you may actually make it worse. You can check the angles yourself using a driveshaft angle finder tool. Its a relitively inexpensive tool.

 

I just learned something new. Thank you @Ruggybuggy.

 

Okay I’m gunna rock the scan gauge for awhile and see if I can catch it again and get a better diagnosis.
Not sure why that didn’t come to my mind. Old as fuck prolly

 

thank you sir.

 

I don't think your scan gauge can help you. With Techstream you can move the needle and check its operation. You can get a copy of Techstream but you will need a way to connect to the obdII port and a laptop

 

Oh I didn’t know that.
But…. This makes me think it isn’t the sensor.

 

If the scan gauge appears to be displaying the correct reading then I would be thinking that the gauge in the instrument cluster is not displaying the correct reading. The coolant temp sensor is just a resistance to voltage and the gauge displays that resistance. If you unplug the coolant sensor you should see the gauge go full cold or full hot. If you jump the harness that goes to the coolant sensor the gauge in the instrument cluster will go the opposite direction.

I circled in yellow the sensor location.



Two pin sensor

 

Disconnected it drops the needle,
Shorted showed no effect
Reconnect shows normal (middle of gauge).
What concerns would you have about it being the instrument cluster.
And also thank you

 

The scan gauge is showing the correct temp and gets the info from the sensor through the ECU. If the sensor was faulty you would think the scan gauge would read a lower temp similar to the instrument cluster gauge. Unfortunately I don't have access to Toyota wiring diagrams. If you do decide to try a sensor it's not a big loss. They were showing $25 on Rock Auto.

 

Just thinking, what position is your needle normally? Your temp is only at 187 degrees.

 

I’ve only had the truck a week. Normally
Needle shows right in the middle.
I did notice yesterday when needle never came up.
I turned truck off and on multiple times (6-7 tries )and then it come up.
During the 6 unsuccessful restarts the gauge bounced ever so slightly.

 

When you unplug the coolant sensor what did the scan gauge read? You must have thrown a code and the check engine light should have come on?

Also because the scan gauge is only reading 187f the needle in the cluster might be accurate. Bring the temp up to 195f and see where that needle sits.

 

Yeah it throws a code unplugged P0118
And reads -40f
Today after warming up in driveway

 

Can you not warm it up to 195 and see where the needle sits? In the pic 167 and needle position seem about right.

 

I thought I had a driveshaft issue ended up being a transmission issue, valve body was worn and damaged the clutches in the torque converter

 

Your click noise ended up being caused by the transmission?

 

No I sure hope not lol, vibration issue I used to have end up being “torque converter shutter” it was a lockout issue caused my wear on components. John at IPT transmissions was a big help.

 

Update on this - -

Prior to my earlier post, I hadn't really fully punched the gas. I'm probably more aggressive than average; but I'm not a foot-to-the floor driver. So just to satisfy the doubt, yesterday I thought I'd test the matter a little and gave it the full dose. There's a little shimmy. I should probably drop the carrier with the 3/4" spacers I bought and see if that improves.

 

Are the wheels lug centric or hub centric on my 2020 Tundra? Would a missing hub centric ring cause a balance issue at certain speeds (between 40-50mph, and above 65mph)?

How common are bad wheels/tire manufacturing issues that could cause a vibration at certain speeds that is also undetectable or unfixable on a tire-balancing machine?

I've got a balance issue on my winter tires that is difficult to replicate according to my mechanic. I've had them rebalanced with different methods several times (including paying for a road force balance at the dealer). Is it possible that winter tires just don't work well on trucks due to soft compounds in conjunction with the sizing? As if the soft compound plus large sidewall (275/65R18) create extra bounce.

 

I saw that on a Tacoma once. The truck was under warranty and Toyota corp only wanted to do the TC. After changing the TC the truck came back needing a transmission as well as another TC after about 2,000 miles of driving. Clutch material from the failing TC can contaminate the transmission.

 

Carmax apparently could replicate the problem. They ordered a new instrument cluster. I’ll let you know