3.4 overheating

Thanks

 

LOL, had the same thing done to my '98 and my scan gauge displayed it runs ~10 degs. hotter when I got it back from the dealer. After mentioning it to the dealer, he gave me another thermostat to try. I installed it exactly like the one I pulled out. It still ran ~10 degs. hotter. Maybe the dealer installed it wrong and I duplicated the error with the replacement. LOL

Before the swap, my scan gauge would not go over 200, even on hot days and long climbs. After the swap(s), it would top out at 210 on hot days and long climbs. I decided it was normal and chalked it up to them using the red Toyota coolant.

Never had an issue and traded in the '98 for my '18.

 

Update
Top hose-hot
Bottom hose and radiator fins -cold
Upper reservoir-hot
Truck scan reads 223 off of obd

 

Just replaced the thermostat. went with an aftermarket. just idling, burping it, got to 225. around the block~231. very little flow through radiator. Removed thermostat and very hi flow. Went on an hour run from 3000 to 5000
' and never went over 161! Went to a smog shop and had it sniffed and 0 hydrocarbons. I understand a faulty t stat once in a while, but all of them??? Should I try a TRD t stat at 160º??

 

I dunno about that 160° thermostat, maybe it's worth doing more testing with it. I'm curious how the temp will be with a normal new OEM thermostat. I'll bet you ride around 190 with new oem one. And that should be the sweet spot. Seems like it'd be nice to get it to that nice baselined spot of fresh rebuild engine and the fresh cooling system works as it's designed. Beautiful. Then if you wanna mess with or adjust things, go for it. You know you can always go back to that oem running cooling system, so messing and testing things isn't a big deal, you know exactly where ground zero is. Feel me? Damn that was a novel, sorry hermano

 

The old saying, which I haven't researched in a while, was that all the oil manufacture's said the oil dosen't start lubing until at least 180 deg. and most later model car manufacture's will not go into closed loop function until 193 to 195,,, that was a general consensus. You'd fail testing besides plugging up cat's because of over fueling (open loop). Toyota's might be different, I'd still be concerned of running to cold because of lubricity reasons.

 

OBDI or OBDII?

 

I have read all 47 post I have a 2003 Toyota Tacoma 4x4 with 3.4 that I just changed the water pump fan clutch and 2 t-stats and I am still running hot. I have a OBDII with app. What started this was the truck ran hot with me one night when I was on the way home. The only thing I haven’t done was get the radiator checked . I am not leaking any fluid.

 

New radiator time...

All good advice so far. You shouldn't have to compensate for higher temps by using a different thermostat. Jiggle valve defanantly in 6 O'clock. Don't drill holes in the t stat!

I had a timing belt water pump service with all the pulleys and goodies replaced only to see my temps running high. I knew immediately they installed the t stat wrong, and sure enough they had it at 12 O'clock.

Top hose hot, bottom cold. Sounds like a clogged radiator to me. Cooling systems are simple. New t stat, pump, fluid full...next is a new radiator. Mine started getting hot sitting in traffic last summer. I checked all the usual things, still getting too warm. New radiator solved it. Mine had 200k, and simply just got old after 14 years of service. Mine runs 191-193, in the Texas 100 degree heat it touches 195.

 

I'm kinda leaning towards what you're suggesting as well, we'll see what he finds. Those are some solid operating temps you're seeing. Did you go with a Denso replacement radiator? Or Harrison (oem)?

 

I bought a Toyota (Denso?) radiator from Toyota Dallas. I always buy Toyota when it’s critical stuff. It just lasts. Fourteen years to be exact.

If yours is original just replace it. You can have it flow tested but it may be more $ down the drain. It’s so easy to swap, and I believe I paid less than $200 for the radiator.

 

I created a post called "Radiator Basics" a while back and it has a picture of what a blocked core looks like... yeah, it isnt a Tacoma but cooling is cooling.

 

Yep, that's what I'm thinking, either the core of the block or rad. or both because of rust, my MIL's truck when I pulled her rad on her Furd truck, the passages coming out of the block were packed solid,,,,, lack of maint. That's why I don't believe or trust the long term anti-freeze, and don't mix the different ones no matter what the box store tells you.

Go down to your local china freight and pick up a thermal gun and shoot your rad. and block, check your temps a bunch of places and see if you can pick up hot spots.

How's your shroud, still in good shape?

 

I have a lot of experience with water wetter, here in Phoenix. It can drop running temps by increasing heat transfer by reducing bubbles, it is a surfactant. We used it racing because you cant use antifreeze on the race track and this wa before other race track approved coolants. A lot of motorcycles, back then, were iffy on running to hot in hot weather at the racetrack and this stuff really worked, yes we used it with distilled water. I added it to my 1972 318 dodge van and it dropped 20 degrees off the running temperature and it would overheat running hills before that. I use it to this day in everything I own and I do run it with the stock coolants in newer vehicles, old vehicle no cold weather I would run this and distilled water still. I have effectively reduced running temps by popping the hood release which gives and inch or two of gap at speed, and of course the old stand by of running the heat at, a real treat when its 114 degrees! Another good one is taking the hood off completely. Honestly it sounds like you have a different problem than just running a little to hot.