Elevated coolant temps but not Overheating

[regularnothing]

Hello everyone

A couple months ago I replaced my radiator and thermostat with an oem one on my 99 lx470. After I changed it I noticed my temps were a little higher than normal but still good so I didn’t think anything of it. I made sure that my jiggle valve was in the correct place and that I burped the cooling system as good as possible. I took a trip to Yuma Arizona recently and on the way there, outside temps were about 105 give or take a few degrees. While driving at 75 mph my temps were 195.8- 197.6 according to my ultra gauge. The next day the outside temps were about the same and driving around town my coolant temps would stay around 198-199. I pulled into a parking lot and idled there for a little while and my temps rose to as high as 205 for a minute but stayed around 201-203 which was a little concerning for me. I’ve read a bunch of other post and I consistently see people say their temps are around 185-190 in similar conditions. Where I live in California I usually see my temps stay at 192-194 and the outside temps are typically around 65-75

 

[Trunk Monkey]

Sounds normal to me. Have you done your fan clutch?

 

[regularnothing]

Sounds normal to me. Have you done your fan clutch?

Fan clutch is Aisin has about 30k miles on it

 

[89BIGBLUE]

Do you have an aftermarket front bumper and a winch?
(Anything blocking lower section of radiator?)

I noticed some increase in temp on my 99 after installing a hidden winch, especially noticeable at certain speeds/MPH.
Not over heating, but higher temps on average when AOT is higher.

A winch holds a lot of heat in it!

I ended up placing some home-made sheet metal "air dams" on both sides of the winch that seems to help at speed. Still watching this summer...

 

[regularnothing]

Do you have an aftermarket front bumper and a winch?
(Anything blocking lower section of radiator?)

I noticed some increase in temp on my 99 after installing a hidden winch, especially noticeable at certain speeds/MPH.
Not over heating, but higher temps on average when AOT is higher.

A winch holds a lot of heat in it!

I ended up placing some home-made sheet metal "air dams" on both sides of the winch that seems to help at speed. Still watching this summer...

I have stock front bumper no winch or nothing. I forgot to mention I have 285/75/17 tires and Asfir skid plate. Not really sure if the tires matter at all since they are heavier than stock and if that makes the engine work harder or something like that.

 

[2001LC]

Thread 'Radiator fins need cleaning! Alert Alert Alert'

Jul 22, 2019

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added radiator cap and thermostat to job, as best practice.

Got me to thinking about the radiators I've been replacing. All have debris built up on lower third.
This one hand some extra grasses along with general clogging on lower third.

Over the years/miles debit builds up in condenser and...

• 2001LC
• Replies: 35
• Forum: 100-Series Cruisers

• 

 

[Trunk Monkey]

OP said new radiator, doubt the fins are dirty already. You said you burped it as best you could, I'd maybe use one of the fill tools that pulls vacuum on the system to fill the coolant. Might have an air pocket.

 

[BullElk]

Thread 'Radiator fins need cleaning! Alert Alert Alert'

Jul 22, 2019

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added radiator cap and thermostat to job, as best practice.

Got me to thinking about the radiators I've been replacing. All have debris built up on lower third.
This one hand some extra grasses along with general clogging on lower third.

Over the years/miles debit builds up in condenser and...

• 2001LC
• Replies: 35
• Forum: 100-Series Cruisers

• 

^^^^ This is my "go to" remedy but I with new radiator then I second @Trunk Monkey and air pocket.

 

[TahoeZ]

OP said new radiator, doubt the fins are dirty already. You said you burped it as best you could, I'd maybe use one of the fill tools that pulls vacuum on the system to fill the coolant. Might have an air pocket.

This is a good place to start IMO. I had quite a challenge getting all of the air out of the 4th gen 4runner I recently replaced the radiator on. Temps were elevated for a while during that process.

 

[Dirt J]

Was there an underlying issue that caused the initial radiator replacement?

 

[regularnothing]

Was there an underlying issue that caused the initial radiator replacement?

My old radiator had a small crack along the top.

 

[regularnothing]

OP said new radiator, doubt the fins are dirty already. You said you burped it as best you could, I'd maybe use one of the fill tools that pulls vacuum on the system to fill the coolant. Might have an air pocket.

I burped it using one of those spill free funnels but I’ll try to use one of those vacuum tools whenever I can.

 

[Dirt J]

Fan clutch is Aisin has about 30k miles on it

Look here, if you want to go down the rabbit hole... I went too far (15k CST) and am going to try 8k.

 

[2001LC]

We've 3 radiators. I wash fins of all 3, even when R&R engine radiator.

Air in system, is a real possibility. Which I see it often. But, he said he burp. Was it re-check?

Reservoir, must also be work properly. As should fan clutch.

Additional consideration, once coolant system to spec. Fuel trims need checking. If running lean, engine runs hot.

 

[Bisho]

Those temps are absolutely normal for the conditions. Don't waste your time chasing your tail.

 

[regularnothing]

We've 3 radiators. I wash fins of all 3, even when R&R engine radiator.

Air in system, is a real possibility. Which I see it often. But, he said he burp. Was it re-check?

Reservoir, must also be work properly. As should fan clutch.

Additional consideration, once coolant system to spec. Fuel trims need checking. If running lean, engine runs hot.

I also forgot to mention my old radiator was a koyo brand one. It had an after market thermostat as well, not sure the brand but it was an 82c and when I had those in, I was seeing temp closer to the 185-190 range which annoys me because now I have oem in my lx and the temps are higher.

 

[shane431]

Strange question but how many miles on your ride? When was the fuel filter changed last? I swear my engine temps are lower after I changed the fuel filter. Seems strange but I rarely see over 188F now. Mostly 186F and I live in Dallas! It hasn’t gotten real hot here yet so that may change!

 

[regularnothing]

Strange question but how many miles on your ride? When was the fuel filter changed last? I swear my engine temps are lower after I changed the fuel filter. Seems strange but I rarely see over 188F now. Mostly 186F and I live in Dallas! It hasn’t gotten real hot here yet so that may change!

I got 220k miles idk when or if it’s even been changed. I have a new one just haven’t put it in yet. I’ll probably try to put it in today or tomorrow and see if it helps.

 

[shane431]

I got 220k miles idk when or if it’s even been changed. I have a new one just haven’t put it in yet. I’ll probably try to put it in today or tomorrow and see if it helps.

It may do nothing! But I swear my truck is running cooler.

 

[NolaNomad]

I recently had temps 215-220 at its highest on stock '06LX470- Sprayed down the radiator as best I could , replaced thermostat with new OEM and gasket, drained radiator fluid also from the 2 engine block points and ran some distilled water, refilled with fresh coolant- now my temps never get above 196⁰F