2002 Toyota Tundra Overheating

Hi Everyone,

First time joining the forum, however I have referenced the forum many times to help answer questions on my Tundra. I'm the original owner of a 2002 Tundra.

I have an issue that I can't figure out how to resolve. My car is overheating ... either by driving about 10 miles in 80 degree weather, or 5 miles in 100+ degree weather. Street driving.

Took the truck to the dealership. They changed the thermostat, water pump, timing belt, serpentine belt, flushed the radiator, and also changed the radiator hoses top and bottom. The car is till overheating. I took it back, and they can't find anything wrong. Unfortunately, it doesn't overheat when they drive it either. The only items I have not changed (so far) are the Radiator Fan Clutch and the Heat Sensor itself. The dealer said the clutch looked good.

Here is what happens. If I drive the streets for about 10 miles or so, I see the heat gauge go up close to red. If I pull over when it is overheating, I do see the fan running (but not sure if there are different levels/speeds it should be running). Also, the fluid in the reservoir tank isn't boiling. I also checked the reservoir tank hose, and fluid is moving to the radiator. If I jump on the freeway, the gauge goes back to the middle and seems like it stays there even when I'm back on the streets. Therefore, it only seems to be street driving that impacts the heat.

Hopefully I shared enough details. If there is anyone that may have any ideas, I greatly appreciate any advice/guidance.

Thank you everyone!

 

If it goes away on the freeway you have an airflow problem. Replace the fan clutch and see where that gets you.

 

I agree with airflow

Also clean your radiator coils with hose. And the ac coils in front of it. They get pretty dirty after 19 years.

 

Serious question: Is your truck really overheating? Or, is it just the gauge that says you are overheating?

Doesn’t sound like you have boiling steaming coolant spewing everywhere is the only reason I ask. Does the engine feel hotter than normal? If it feels normal, it may just be that Temp Sensor is failing and giving you a false reading.

 

The dealership flushed the radiator, but how clogged are the passages between the Cooling fins? I would clean the exterior of the radiator, condenser and trans cooler as well. Better yet Pick up a new radiator and start fresh. Or, as PHM suggests, start with a new temp sender.

 

Thank you everyone! These are really great and helpful responses, which I appreciate very much. Took it out for a drive again today ... after about 20 to 25 minutes (street driving) in about 85 degree weather ... the temperature gauge started going up to the 3/4 range. I then turned down a street that was downhill and was able to go a little faster ... and felt the wind against the truck was greater also ... and the gauge went back down to the middle very quickly and stayed there the rest of the way home. No steam, no boiling coolant (to answer the question above). It looks like we are between the fan clutch, or the heat sensor and/or like noted the air flow in the front of the radiator. I changed the radiator a few (~5) years back ... however, it could probably get dirty (and has been sitting longer than usual with this pandemic). I assume the quickest options are to hose off the coils and replace the sensor first before the fan. I will give those a try. You all are the best. Please know I truly appreciate the great advice. The advice you have all shared on other posts have helped me many times in the past. I knew I could count on getting great help with this as well.

 

Do you know anyone with an infrared temp gun? Easy way to test your coolant temp sensor.

I’m going with the viscous fan hub. Do you still get the 10-30 seconds of fan roar on cold start-up?

 

Don't know anyone with a temp gun. :-( However, interesting you brought up the fan roar. Not sure if I am still getting that. I will have to try it out tomorrow and see if that still happens. If I don't get that fan roar, is that an indicator the clutch isn't doing well? Thank You!

 

Yeah, it’s not the be-all, end-all of tests for viscous fan hubs, but if it doesn’t roar I’d say it’s the final nail in it’s coffin.

Look at Aisin replacements, since they supply Toyota for the OEM parts.

 

Thank You! I will try it out tomorrow.

 

Oops. I edited my post so it says what I meant.

 

LOL. All Good. Thank You again!

 

Get something like the scangauge and monitor your coolant temp that way

 

For around $15 you can buy an OBDII bluetooth reader and the Torque Pro app. This will allow you to do what Pucks said.

 

Thank you both! I will look into these.

 

Hi Everyone,

Just wanted to loop back on the resolution. Looks like there was blockage in the center row of the radiator. I guess it was only impacting the car after a 25 minute street drive (in ~85 degree weather) ... or within a 5 mile street drive (in ~100+ degree weather). The dealer swapped out the radiator for a new one ... took the car out today in the 100+ degrees we are getting ... and the needle stayed in the middle (expected) area the whole drive.

Thank you all again for the great suggestions and advice. I believe a few posts called out the radiator as well. I truly learn a lot from the fellow Tundra owners on this forum, and the knowledge you have shared has helped me many many times.

Stay safe and healthy everyone!

 

Stoked its working and thanks for reporting back!

Blockage was inside the radiator? Reason I ask is I watched that A1 Auto youtubes on Timing Belt swap. Guy pulled the radiator and the middle row, as well as dead center bulls eye looked cacked up with road debris. This was the area sandwiched between the A/C Coil backside. A hard to feather dust location.

 

Glad to hear it was resolved. My previous LS430 was experiencing similar problems with its radiator and a replacement solved the issue. At first glance, the radiators look very similar between the Tundra and the LS.

 

Thank you both!! Yes, I am stoked it worked also ... especially after 4 trips to the dealer trying to figure it out. Thankfully (in a way) the last time I dropped it off it was 100+ degrees outside ... so they finally saw it overheat. Once they pulled out the radiator they saw antifreeze build up around various parts of the bottom portion. Almost like it was dribbling out starting from around the middle area and then going down and drying on the outside of the radiator. You can see the trail from the middle to the bottom. Not an easy area to see (or feather dust) as noted. They tested further, and were able to confirm that there was blockage in the center row. Swapped it out, and thankfully all good now. I did have the radiator changed about 5 years ago ... but in those days the old one was splitting across the top (after 14 years of use) ... so you could see the antifreeze coming out and getting all over the motor. I guess 5 years was it for that new one. Regarding the LS, I do see that they look very similar. Happy the radiator swap worked for you too. So many different things that could cause the issue. Well I definitely learned a lot with this one, especially with all the great advice and suggestions shared here also. Thank you all again!

 

JMH2000:

I am glad to hear that your radiator issue has been resolved.

I bought a new 2002 Tundra Limited 4.7 extended cab in October 2001. I have now driven it over 265,000 miles of very dependable service. One thing that I have really appreciated with the Tundra is the performance of the cooling system. No matter how hot the weather or what I am pulling, the temperature gauge sits right in the middle.

I have had GM, Ford and MOPAR vehicles that overheated, especially when towing a heavy boat or trailer. The Tundra never has given me an overheating problem in 19 years.

Up to 190,000 miles, my Toyota dealer performed all maintenance. I switched to an independent garage at 190,000 miles when a Toyota tech lied to me about needing to rebuild the differential at a cost of over $5,000. I went to an independent garage that specialized in transmissions and drive lines. They correctly diagnosed the problem (excessive vibration caused by the front section of the driveline being out of balance.) and rebuilt the drive line, u-joints and central support for under$800. The differential now has over 80,000 miles on it since the drive line was rebuilt. The Toyota tech told me that he could see a "hop" in the wheel when the engine was run while the truck was suspended on a hoist. The wheel ran smooth at the independent garage. IMO, he lied.

The independent garage noticed a pinhole leak in the radiator while I was getting the drive line rebuilt. It was not a big leak but you could see evidence of the leak so we replaced the radiator. Last year, when I had the timing belt and water pump replaced, we noticed a small pinhole leak in the radiator that was dripping fluid on the shroud that runs under the engine. The drip was so small that it never left fluid on the ground under the truck.

I am pleased with the truck but I am on my 3rd radiator. Be sure that your radiator has adequate coolant. A leak could cause a loss of pressure which could cause overheating.