Running warm after timing belt/ new radiator

Hey guys any ideas would be greatly appreciated.
So since my 2002 3.4 Tacoma is about to hit 200000 I figured I’d do some good preventative maintenance. Did a full timing belt job (belts, pullys, water pump etc.) new spark plugs, wires, fuel filter, and new oem radiator and hoses, and all new fluids.
anyway now, as per my ultra gauge I’m running a fair bit hotter. Used to be 189-194 average and hottest I’d ever seen it maybe 202, now I’m running 199-206 average and have seen 213. According to the internet I was convinced it was because I installed the jiggle valve at 12 o’clock not 6 so today I cracked it open and flipped it… same temperature to the degree while driving, 204.8 just cruising along. Under harder load (I’ve got a big pass near my house that goes from 4000-7500 feet) it cools down and stays at 199 for the whole climb. Any thoughts would be appreciated

 

Do you think that there is some air left in the cooling system?

 

check the upper hose and see if it gets hot when sitting in the driveway/street (I think this is the return to Rad hose) when at "operating temp"

like @USMILRET mentioned could be an air pocket somewhere. if you can put it on an incline as well with the nose up

 

This.

Yu could open the radiator with the trucks front end on an inlcine, see what air you may burp out.

I had this happen before when it was slightly over filled as well.

Its fun being ocd isnt it!?

 

Thanks for the ideas guys, I’ll try giving it another good burp today and see if that helps sort it out.

 

Few days(videos) ago Scotty was working on a corolla and said the valve always goes at the 12 o'clock pos...

https://www.toyotanation.com/threads/thermostat-jiggle-valve.326683/

Scotty Kilmer - YouTube



Dont think this is your problem.......what about the plugs.....could the new plugs be running hotter?
Heat can be lean fuel system......or not getting out of that closed-loop...at start up..
Clogged EGR can cause lean......aftermarket parts/sensors can cause weird things...

Find somebody with scanner and run/study the live data.........if u dont what it means....somebody damn sure will here.....


Unfortunately I tend to bite off more than sensible.....instead of changing one or two things at a time - so to trouble shoot as go a long....
I do too many things.....and with a 24yr old vehicle.....that's not wise....
Its bit me in the ass a number of times......like last weekend......destroyed front tires....too big hurry...simple mistake....

 

Did you change the thermostat?

 

I’d start with the thermostat. I’ve used the asin thermostat off rock auto. If there was air in the system the truck would overheat, but a minor difference In temp sounds like the thermostat

 

don't forget to turn your heat on, and make sure the water is flowing through your heater core. And like others have stated try parking on an incline to burp the system.

 

Id also suspect the different thermostat, or maybe the fan clutch was damaged while taken off.

Changing radiators is something I do atleast a couple times a week. Typically when there is trapped air the overheating is quick and hot, heater won't work and in some cases the temp gauge doesn't work.

I usually use a vacuum system to fill radiators and it works great, that large yellow funnel seems to work as well but I prefer the airlift system.

 

Thanks to everyone that’s chimed in, I really appreciate it. I think Probably thermostat as well. Today I did try to re-burp the system but no bubbles. Drive home from work today settled right back at 204.8 so the coolant system seems to be doing a good job at keeping it at a certain point that point is just higher than I’m used to seeing. I did replace the thermostat with a new Toyota oem 180 degree unit but I did read somewhere on the inter webs today that the new Toyota 180 seem to be slower to open than the old ones so that might make sense. any opinions on running the stant 170 thermostat?

 

I just changed the hoses, hardware, OEM thermostat and flushed my coolant system last weekend. FSM say the thermostat jiggle valve on 2.4/2.7 is in the 12 oclock position (+15/-15 degrees). For 3.4 it is in the 6 oclock position. I tested my thermostat before installing as suggested.

Might be worth to take a look at the condition of your radiator cap as well. How is the rubber? An unpressurized system will run hotter. Sometimes its the simple things that cause problems.

 

I also noticed an increase in temp after a thermostat replacement on my 2000 4runner, but not quite the difference you noticed. Mine went up around 4-5 degrees. I decided to do a comparison test of the old thermostat with then new thermostat. I put both in a pot on the stove and brought the water up to normal operating temp, around 190 degrees. What I found by taking measurements is the old thermostat opened up further than the new thermostat at the same temp. Knowing this, it now made sense why I was running a little hotter with the new thermostat because it wasn't opening as far. Over the thousands of heating and cooling cycles, that thermostat spring must loose some of it's strength and allow the thermostat to open a bit wider letting a higher flow of coolant to get past.

What I decided to do is put back the old thermostat. There's not really a whole lot that can happen to a thermostat so I felt totally fine running the old one. I carry the new one as a trail back-up. I suggest putting in your old thermostat and put the jiggle valve at the 6 o'clock position. Scotty Kilmer is a knowledgeable guy, but he doesn't know the nuances of this 3.4 liter engine. The jiggle valve definitely needs to be at the 6 o'clock position.

I am running a Stant 170 degrees thermostat in my 98 4runner without issue. Because that rig is heavily modified with a lot of extra weight, the engine can run hotter when the engine is straining up grades in hot ambient temps. The 170 degree thermostat helps a little.

 

there is a better mousetrap out there… Failsafe makes a thermostat that when it fails, it fails open. In addition if there is an overheat situation, it locks in the open position. https://motorad.com/products/fail-safe-thermostats/

 

Just wanted to follow up in case anyone finds this thread looking for answer in the future. Ended up replacing the new Toyota OEM 180 thermostat with a aisin brand 180 thermostat. temps dropped from 204.8 cruising to 183.2 cruising. Don’t know if my Toyota brand one was faulty or if the new Toyota thermostats just don’t open till much later than 180. Thanks again to everyone who offered ideas.