Normal coolant temps

[mtbtim]

I finally saw temps above 193 on a long climb (OD off, 60mph, 6-8% grade, 110*F for about 6 miles, loaded with wife/daughter/gear for a week in the mountains). Got up to the low 200's - once the climb was done, it was right back down to 191*F. Trans temp was in the 220-240 range with only the stock cooler. So there, finally found a situation that can get it to rise above 'normal' :smokin:

-Charlie

I've seen similar coolant and trans temp numbers climbing in the mountains loaded down with gear. I actually hit 240 with my trans on a ridiculously steep and relentless mountain road in the Santa Cruz mountains. I had my rig loaded down with 4 passengers and went up this road that had to be a 15% grade for a few miles. Even with an external trans cooler, I still got it up that high. I was just about to stop to let the trans cool when we finally arrived at our destination.

 

[phattyduck]

Did you use the OD override? :cowboy:

Yup, also part of why I was driving 60mph. Keep in mind this was on a 110*F day. With the stock trans cooler in the radiator, the temps hover around 100*F more than the outside temp when cruising with the torque converter locked up, so even before the hill (errr... mountain) they sit in the 190-200*F range.

Those ambient temps are very rare around here - if I lived out in the desert, I would definitely be getting an extra trans cooler. Heck, I might anyway...

-Charlie

 

[DK327]

This was exactly my experience, went from 207 to 188 just by re-doing the jiggle valve from 12pm to 6pm. This was a year ago, now I'm running at 191F consistently, still see 188 occasionally. Never over 193F.

I just hit 250K miles and got the timing belt water pump done along woth drive belts. On the highway i noticed 215F engine temp and almost shit my pants! I guess i need to drain the coolant and check the jiggle valve position, once again.... Will report back with findings...

 

[mtbtim]

I just hit 250K miles and got the timing belt water pump done along woth drive belts. On the highway i noticed 215F engine temp and almost shit my pants! I guess i need to drain the coolant and check the jiggle valve position, once again.... Will report back with findings...

I guarantee your jiggle valve is at the 12 o'clock position.

 

[DK327]

I guarantee your jiggle valve is at the 12 o'clock position.

Yep sure enough it was at 12pm, switched to 6pm and I’m back down to 190F. A whopping 25F difference! So much for toyota master techs following the FSM religiously. Insult to injury was the thermostat housing nuts which were tightened like someone’s life depended on it... :bash:

 

[mtbtim]

Yep sure enough it was at 12pm, switched to 6pm and I’m back down to 190F. A whopping 25F difference! So much for toyota master techs following the FSM religiously. Insult to injury was the thermostat housing nuts which were tightened like someone’s life depended on it... :bash:

Well Brother, you just learned a valuable lesson. There's really nothing special about dealership mechanics or paid mechanics in general. Yes, some are awesome and take pride in their work. Others are trying to finish your repair asap because they are Flat Rate mechanics and are rewarded for finishing the job fast. I still use shops and experts for things I can't do myself like wheel alignments, balancing wheels, turning rotors, and welding since I don't own a welder or know how to weld YET. With all the information available to DIYers on the internet, we can do just as good and most of the time better than the paid guys because it's our rig, friend's rig, or family's rig and we're not in a rush to get it done. We're going to take our time and do it right.

I just did the valve cover gasket job on my 98. Found a chipped half moon and the cam plugs were smeared with sealant. I know I didn't break that half moon and l also know that sealant is not needed on the can plugs so its obvious the previous owner had the valve covers done sometime in the past. Also, the spark plugs were single electrode. I can rest easy knowing the job was done right this time.

 

[GuardianAgent]

High Coolant temps when towing

My ride - 05 SR5 2WD auto 98k

Add ons in preparation of towing a 24ft tandem axle travel trailer with a max GVWR of 7500

Tru-Cool - Max LPD47391 47391 Low Pressure Drop Transmission Oil Cooler
AIR LIFT 60809 1000 Series Rear Air Spring Kit
Draw-Tite 75155 Max-Frame Receiver 7300 GTW
OBDII bluetooth scan tool with Torque Pro app
Tekonsha 90195 P3 Electronic Brake Control


On my first trip out with the trailer at GVWR of 5500, I kept it in 4 pretty much my entire trip. The trip was about 460 miles roundtrip with mountain travel of about 6% grade for about 50 miles. The outside temp was mid to upper 80's. About 150 miles into the trip, the alarm I have set for high engine coolant (220°) went off. The temp stayed around there for about 15-20 minutes before I was able to turn off the engine while fueling up. This occurred on the return trip in very similar fashion.

This is really the first time I've watched my temps using Torque Pro with or without towing so I'm not really sure what is normal for my vehicle. My 4Runner came with the trans cooler inside the radiator which is why I added the external cooler.

My current concern is the high coolant temps. Is it possible the large trans cooler (8.5"x22.75"x1.25") I installed in front of my radiator is causing it to be inefficient? I plan to check and possibly replace the radiator cap, tstat with drain and refill (with JV at 6 o'clock), and fan clutch.

Any other ideas/options would be greatly appreciated.

Thanks

 

[jgue467]

Temps seem what they'd be while towing 6 degree grades with that weight. Would only be in the 190-195 range otherwise.

My external radiator (and most everyone else's) is in the same place, makes no real diff.

If original radiator, I'd recommend replacing it to prevent the pink milkshake to the tranny. Otherwise, goodluck! :cowboy:

 

[phattyduck]

My ride - 05 SR5 2WD auto 98k

My current concern is the high coolant temps. Is it possible the large trans cooler (8.5"x22.75"x1.25") I installed in front of my radiator is causing it to be inefficient? I plan to check and possibly replace the radiator cap, tstat with drain and refill (with JV at 6 o'clock), and fan clutch.

Any other ideas/options would be greatly appreciated.

Thanks

You have a 4th gen. You don't have a 5vz, so the jiggle valve advice is probably not correct. The 4th gen guys can probably help you more...

Checking all the rest (t-stat, radiator cap, etc.) are all good ideas though.

-Charlie

 

[nchacon1984]

I've had the the water pump, t-stat, radiator cap replaced by a buddy when I first got my 4R. After reading most of this thread and watching Tim's video. I'm getting temps around 190F to 195F while cruising and 199F to 204F at stops. Radiator is the original though and is on my to do list to replace but Im thinking the t-stat might be in the 12 position.

Would I be able to just flip it to the 6 position without flushing the radiator?

 

[phattyduck]

Would I be able to just flip it to the 6 position without flushing the radiator?

You will need to drain the radiator - but if you catch it in a clean container you can just reuse it.

-Charlie

 

[alumarine]

I've had the the water pump, t-stat, radiator cap replaced by a buddy when I first got my 4R. After reading most of this thread and watching Tim's video. I'm getting temps around 190F to 195F while cruising and 199F to 204F at stops. Radiator is the original though and is on my to do list to replace but Im thinking the t-stat might be in the 12 position.

Would I be able to just flip it to the 6 position without flushing the radiator?

Yes, you could flip it without flushing the rad.

 

[Team_Jake]

Thread resurrection...

I'm going on a road trip in a couple of weeks, and part of it will include driving a fully loaded 4Runner through the California/Nevada desert in the middle of the day. I anticipate the weather will be ~115°F and there will be some steep climbs, this will probably be the hottest my engine will ever be.

There are some obvious things I can do to keep my engine happy during a scenario like this (like turning off the A/C, going slower up hills / using lower gears, etc.) My question is what else can I do to ensure my engine stays happy? The first page of the thread suggested Redline Water Wetter to keep temps cool, has anyone had success with this or a similar product? What temperature would be considered "too hot", that would be in my best interest to pull over and let my engine cool down (looking back through this thread, someone said their radiator cap failed at 222°F, so maybe as long as I stay under that I should be good)?

And to give a little background, my coolant temps normally read 190°F - 194°F on my UltraGauge (70°F weather and driving around town). My jiggle valve is at 6 o'clock, I use Toyota Red Coolant, I have a 5VZ, R150F, 4.30 gears and 33.5" tires. The highest I've seen my coolant temps get up to is 208°F while climbing a mild grade in 110°F weather, fully loaded, A/C on.

 

[19963.4lsr5]

I have a fresh engine, new rad, new fan clutch and in 100 degree humid heat with AC on max in never seen above 191.


Sent from my iPhone using Tapatalk

 

[phattyduck]

What temperature would be considered "too hot", that would be in my best interest to pull over and let my engine cool down (looking back through this thread, someone said their radiator cap failed at 222°F, so maybe as long as I stay under that I should be good)?

You'll want to keep moving, generally, in really hot weather. The only time I've come close to overheating (on an otherwise good cooling system, including track days) was a 115*F day here coming to a stop (traffic) on the freeway after about 10 miles of normal driving. Different vehicle, but same circumstances. I think it would be a bad idea to come to a stop to cool things off in really hot weather.

I'd say keep the speed reasonable, drop to 4th and 55-60mph when necessary up hills and you'll be fine. The factory gauge doesn't even move from the middle until you are at something like 210-215*F. Sounds like you will be fine.

No auto trans to overheat. arty:

-Charlie

 

[toverturf]

I was driving on the freeway today in about 104F heat doing about 65-70mph and I was at 211F with AC full blast. Definitely seems hotter then it should be. I replaced the radiator, cap, hoses, new thermostat at 6 o'clock with all OEM parts, and have flushed the system out with new Toyota red/pink coolant. That was all about 2 months ago. I plan on replacing the fan clutch in the next few days because it does fail the shut off engine test after it's warmed up. Spins more then it should and you can spin it quite a bit once the engine is off. Any other ideas what it could be if that's not it? I have 211k miles on the car and idk when the timing belt and water pump was changed last.

 

[Thebeastlives]

In the 16 years that I've owned this 96 4runner it has never run anything but 190 to 193. Doesn't matter how hot it is in Az or even how big the hills are. I just took a trip from Tucson to the white mtns and all I did was climb and climb with the AC full blast with outside temps of 105 to 108. I've never owned a Toyota that had overheating issues unless there was a leak in the coolant system. Even with a blown head gasket the 3rd gen didn't over heat it just ran like crap and blew white smoke. If you have overheating issues check your entire coolant system.

 

[mtbtim]

I was driving on the freeway today in about 104F heat doing about 65-70mph and I was at 211F with AC full blast. Definitely seems hotter then it should be. I replaced the radiator, cap, hoses, new thermostat at 6 o'clock with all OEM parts, and have flushed the system out with new Toyota red/pink coolant. That was all about 2 months ago. I plan on replacing the fan clutch in the next few days because it does fail the shut off engine test after it's warmed up. Spins more then it should and you can spin it quite a bit once the engine is off. Any other ideas what it could be if that's not it? I have 211k miles on the car and idk when the timing belt and water pump was changed last.

I see those kind of temps with my 98 in very hot weather but my 98 is heavily modded with aftermarket bumpers, aftermarket skids, roof rack, etc that has added a lot of weight to it. The aftermarket bumper with a winch also does inhibit air flow through the cooling fins of the radiator and I know that definitely has something to do with it. Also, if you're putting a heavy load on the engine, like when you're climbing grades, your coolant temp will go up higher as well.

So, a lot of it has to do with the Ambient temp. The hotter it is outside, the hotter your engine will run in certain situations. On a flat highway, cruising at a mellow speed that's not putting a strain on your motor, your coolant temps will be normal. Start pushing the motor by trying to maintain a fast speed or by climbing a sustained grade, your engine temps will go up. I've seen this with both my 3rd Gens but it's definitely worse with my 98 because of all the weight I'm carrying around and the reduced air flow through the radiator cooling fins.

 

[thegipper]

I see those kind of temps with my 98 in very hot weather but my 98 is heavily modded with aftermarket bumpers, aftermarket skids, roof rack, etc that has added a lot of weight to it. The aftermarket bumper with a winch also does inhibit air flow through the cooling fins of the radiator and I know that definitely has something to do with it. Also, if you're putting a heavy load on the engine, like when you're climbing grades, your coolant temp will go up higher as well.

So, a lot of it has to do with the Ambient temp. The hotter it is outside, the hotter your engine will run in certain situations. On a flat highway, cruising at a mellow speed that's not putting a strain on your motor, your coolant temps will be normal. Start pushing the motor by trying to maintain a fast speed or by climbing a sustained grade, your engine temps will go up. I've seen this with both my 3rd Gens but it's definitely worse with my 98 because of all the weight I'm carrying around and the reduced air flow through the radiator cooling fins.

[MENTION=120071]mtbtim[/MENTION]

My 97 does the exact same thing. If I'm driving around town or on the freeway, temps are always 194 or lower. The second I hit the trails on a hot summer day, they rise quite a bit.

On my last trip to our hunting land, I had the AC on while I was on the trails (low 90s temp, high humidity) and the coolant temp was 210. I chickened out and turned the AC off which brought it down 5 degrees or so.

I've watched your fan clutch video a few times. Were you ever able to get your temps back down permanently?

Basically everything in my cooling system is under a year old minus the radiator (5ish years old) and the fan clutch.

I haven't done the fan clutch test yet but plan on doing so.

And as a general question for everyone, are guys able to run their AC on the trails and keep their temps under 200? Or is it just not possible to keep the temps that low in the summer heat?

I'll drive on the exact same trails in fall when it's not so hot out and temps never go above 200.

 

[heat]

What's your engine speed when it starts to heat? 1500 rpm might keep things
cool at highway speeds, but maybe not when creeping around in hot temps.