Quick Rise in Coolant Temp — Normal or Abnormal?

[nissanh]

I think it is this

Also clean the fins of your condenser and radiator. But I would guess that the fan clutch is where you need to start.

If the cooling system has been opened it may need a good burping.

^^^
What do you have in front of the grill? have you covered the lower valence? Did any modifications to the grill like those fancy aluminum strips?

If not, then yes, clean the ac condenser and radiator cooling fins and surely replace the clutch.

I get 85-95 C (185 to 203F) measured at the upper coolant output with an IR thermometer. This is with AC on in West TX in a hot summer day. I have two 8 inch fog lights which I plan to remove soon after watching the following video!

See 1:25 mark here: https://www.youtube.com/watch?v=h5hN57NpI_g

 

[jeremyc74]

^^^
What do you have in front of the grill? have you covered the lower valence? Did any modifications to the grill like those fancy aluminum strips?

If not, then yes, clean the ac condenser and radiator cooling fins and surely replace the clutch.

I wouldn't suspect a grill modification is the issue, since he's taking his measurements sitting still.

 

[StreetCreeper]

^^^
What do you have in front of the grill? have you covered the lower valence? Did any modifications to the grill like those fancy aluminum strips?

If not, then yes, clean the ac condenser and radiator cooling fins and surely replace the clutch.

I get 85-95 C (185 to 203F) measured at the upper coolant output with an IR thermometer. This is with AC on in West TX in a hot summer day. I have two 8 inch fog lights which I plan to remove soon after watching the following video!

See 1:25 mark here: https://www.youtube.com/watch?v=h5hN57NpI_g

Stock bumper, grill and valence. I did just remove the dealer installed Hella fog lights, so there should actually be more air flow when moving. But as Jeremyc74 mentioned, the temp only rises when sitting still.

I'm considering replacing the Hella fog lights with a simple led light bar in that location. Maybe a 20 inch so there is still good air flow through.

 

[nissanh]

Probably it is your fan clutch, or it could be the water pump not doing its job right at idle. Have you check the temperature while the rpm is around 1500 - 2000 and at still ?

 

[StreetCreeper]

Probably it is your fan clutch, or it could be the water pump not doing its job right at idle. Have you check the temperature while the rpm is around 1500 - 2000 and at still ?

If you mean rpm at 1500 - 2000 while stationary then no. Whilst driving then yes. At highway speeds and around town it's typically between 191 and 197 with the rpm in that range.

I've considered the water pump too. Hoping that's not it, however, I'm am due for a timing belt replacement, so the pump might be starting to fail. I haven't noticed any pump weeping but on occasion I swear I can hear the slightest squeak of a water pump.

 

[LittleCaesar]

If you have gotten 400,000 miles on an original fan clutch then you are good. I have seen OEM ones on other cars and trucks die as fast as at 100k.

I'd start with a new fan clutch and OEM radiator cap and go from there. When I replaced the cap on mine a few years back, it was still OK but the new one allowed the 4runner to warm up much faster.

At 90 degrees with 60% humidity and my AC blowing at 40F I am idling at 191F usually. My 4runner runs cooler during the summer months than in the wintertime.

 

[StreetCreeper]

If you have gotten 400,000 miles on an original fan clutch then you are good. I have seen OEM ones on other cars and trucks die as fast as at 100k.

I'd start with a new fan clutch and OEM radiator cap and go from there. When I replaced the cap on mine a few years back, it was still OK but the new one allowed the 4runner to warm up much faster.

At 90 degrees with 60% humidity and my AC blowing at 40F I am idling at 191F usually. My 4runner runs cooler during the summer months than in the wintertime.

I'm unsure if it's the original. But considering that damn near everything else on this truck is original — it's highly likely.

Since I'm already replacing the radiator in addition to OEM thermostat and cap, I'm going to hold off on the clutch to see if it's just the radiator.

TBH I wasn't entirely sure I was looking at an issue at all. But the temps did seem a bit high for the conditions and it seems most folks on here think the same. So I'll report back as I try a few things and see what sticks.

This is one reason why I jumped on the ScanGauge when I saw it for sale. My hope is that with better info, I can identify potential problems before they really cause a problem or stress out other components.

 

[nissanh]

Drain about 1 quart of coolant and inspect the inside of the radiator upper tank. I had an mysterious temperature fluctuations, specially when going up hill. Even bought a fan clutch, but later found out about 38 out of 48 or so tubes were fully clogged.

 

[StreetCreeper]

Drain about 1 quart of coolant and inspect the inside of the radiator upper tank. I had an mysterious temperature fluctuations, specially when going up hill. Even bought a fan clutch, but later found out about 38 out of 48 or so tubes were fully clogged.

Interesting. Clogged with what?

 

[Joe Z]

It's a little port covered by a metal check valve. You can see it at about 2 oclock in this picture.

Thanks for taking the time for that picture.....When i get in there i will check it out

 

[jeremyc74]

Thanks for taking the time for that picture.....When i get in there i will check it out

Just FYI, normally the jiggle valve goes at the 12 'o clock position which helps allow air to pass through. There's something about the design of the coolant path in this engine causes it to work better when placed at 6. The official Toyota service manual tells you to place it at the 6, but a lot of the aftermarket manuals (Haynes) still say to put it at 12. For some unknown reason this engine runs several degrees hotter with it at the 12, and there are a ton of people on this forum who have witnessed it.

Typically a truck that has been serviced at the dealership will have it in the right way, but a lot of independent shops don't know about this quirk and put it in the wrong spot.

 

[Joe Z]

Just FYI, normally the jiggle valve goes at the 12 'o clock position which helps allow air to pass through. There's something about the design of the coolant path in this engine causes it to work better when placed at 6. The official Toyota service manual tells you to place it at the 6, but a lot of the aftermarket manuals (Haynes) still say to put it at 12. For some unknown reason this engine runs several degrees hotter with it at the 12, and there are a ton of people on this forum who have witnessed it.

Typically a truck that has been serviced at the dealership will have it in the right way, but a lot of independent shops don't know about this quirk and put it in the wrong spot.

Like you in Florida, things get awfully hot here in Arizona and cooler is better.
Thanks

 

[nissanh]

Oh

Interesting. Clogged with what?

Clogged with sediments in the coolant.

Glad I caught the temp gauge climbing up while I was heading to Reno from Sacramento. Quickly pulled over and allowed it to cool. Then I called a friend of mine to bring a fan clutch as I suspected it. Installed it and continued the journey and in about 3-4 miles again the same thing. Pulled over and this time I suspected the thermostat. I opened the thermostat housing and saw it was fully open. Then noticed the radiator tubes that runs from top tank to bottom tank was covered with find dust like sediments. After finding the issue, drove down hill back to Sac. No issues down hill. Got a new radiator next day and have had no issues after that! Before we tossed in the old radiator to trash, we crak open the top tank and found out 38 is fully clogged.

 

[sugjavier]

Help

Hi guys,

I couldn't find a better thread to revive so here it is.

It was 91 out today and I was in a long drive thru (~15-20mins) and noticed my temp gauge went almost to red!!!

Here's a pic

I know it only did this in idle cuz I always watch the dash for Temps etc. I never seen it like this high before. I did remember a couple years ago it went up like a couple cm past the halfway mark when I sat in idle for 20 mins with AC on and it was hot out.

I had the AC on "cold" so the coolest setting and the fan was at 2 bars so not even full blast.

Is this normal or should I get it checked out???

I checked for any coolant leaks and didn't find any. The reservoir is full and didn't lose any coolant from the last time I checked it 2 weeks ago. I also got the coolant flushed recently and the radiator is 4.5yrs old (replaced with a Koyo one) along with the cap and hoses.

From what I read it could be a fan clutch which I have no problem buying since it's $90 on Amazon and from what I read it's pretty easy job for my mechanic to do.

It went back down to normal ish as I drove home for about 25 mins

 

[spartacus]

[MENTION=10169]TheDurk[/MENTION] had a good post of how to test the fan clutch i cant seem to find it but if you start the truck from cold the fan speed should go up with the rpms and also the risky rolled up newspaper test and replacement [MENTION=120071]mtbtim[/MENTION] has a video on how to replace the fan clutch. Make sure the thermostat is good and the radiator is not clogged.

 

[sugjavier]

I just search "test fan clutch" using the custom google site for the 3rd gen.

https://www.toyota-4runner.org/1753010-post8.html

Testing the fan clutch:
If you have reason to suspect that the fan clutch is defective, here is the recommended procedure to verify the condition of the fan clutch.
1. Start the car (cold) with the hood open and note if the fan is turning, increase the engine RPM and note if the fan turns faster and the noise increases, if it does, first good indication, if it does not increase speed/noise, clutch is bad and needs to be replaced. (Remember, this must be tested after the car has been off for and extended period, over night etc.)
2. Leave engine running and note if the fan starts to slow down after 2-5 minutes, speed/noise should diminish and even raising the RPM, the fan should not make as much noise as when first starting, if it does slow, this is the second good indication. If speed/noise does not decrease, clutch may be “frozen” and should be replaced.
3. Leave the engine idle and watch the temperature indicator. When normal operating temperature has been reached, some increase in fan speed/noise should be noted, in particular when the RPM is increased. If temperature is fairly stable and the fan noise/speed increases or cycles, third good indication. If temperature indication continues to increase, with no increase in fan noise/speed, clutch is defective and should be replaced.
4. After the engine is at normal operating temperature or above, is the only time that the “rolled up newspaper” test that many people talk about should be performed! Take some newspaper and roll it up into a long narrow tube. Be careful, keep hands and fingers away from the fan while performing this test! With the engine at full operating temperature and idling, take the rolled up paper and insert it on the back side of the fan and try to reach the hub of the fan avoiding the blades until close to the hub. Push the rolled paper at the fan increasing the friction to the hub area of the fan. If the fan can not be stopped easily this is the fourth good indication, if it can be stopped the clutch is defective and should be replaced. Again, this test can only be performed when the engine is at or above full operating temperature.

Testing can be performed in any order but just make sure the conditions during testing are those that are specified for that specific test.
Do not continue to operate the engine if the temperature continues to rise and certainly stop if the temperature approaches “redline”.



That should be it, I'll test it tomorrow morning. Thank you!

 

[Joe Z]

Hi guys,

I couldn't find a better thread to revive so here it is.

It was 91 out today and I was in a long drive thru (~15-20mins) and noticed my temp gauge went almost to red!!!

Just and educated guess but here it is..... Your radiator has vertical water jackets meaning the water goes vertically thru the radiator...... get dirt buildup at the bottom inside and waterflow is restricted..
Make sure the outside of your radiator is free of bugs and dirt too
Do this free test...get the engine up to normal or better operating temperature. Shut the engine down and quickly go out and feel the radiator at the bottom of the fins then up at the top. If the bottom is much cooler you likely have dirt obstruction....
It could be the clutch fan so test it out..... it should spin with some restriction.

 

[19963.4lsr5]

Hi guys,

I couldn't find a better thread to revive so here it is.

It was 91 out today and I was in a long drive thru (~15-20mins) and noticed my temp gauge went almost to red!!!

Here's a pic

I know it only did this in idle cuz I always watch the dash for Temps etc. I never seen it like this high before. I did remember a couple years ago it went up like a couple cm past the halfway mark when I sat in idle for 20 mins with AC on and it was hot out.

I had the AC on "cold" so the coolest setting and the fan was at 2 bars so not even full blast.

Is this normal or should I get it checked out???

I checked for any coolant leaks and didn't find any. The reservoir is full and didn't lose any coolant from the last time I checked it 2 weeks ago. I also got the coolant flushed recently and the radiator is 4.5yrs old (replaced with a Koyo one) along with the cap and hoses.

From what I read it could be a fan clutch which I have no problem buying since it's $90 on Amazon and from what I read it's pretty easy job for my mechanic to do.

It went back down to normal ish as I drove home for about 25 mins

Did you also remove the rad cap to see if coolant is touching the bottom of the Rad cap and you’re not low on coolant?


Sent from my iPhone using Tapatalk

 

[sugjavier]

I did check the radiator cap.

Here's what it looks like: cap

I did notice a small coolant that dried off on the right side.
As far as flushing, it was recently done like a month ago. Is that color normal?
I know we used Zerex Asian formula which is red or pink.

I'll be testing the fan clutch later this afternoon

 

[sugjavier]

So I did Durks tests and able to pass 1-3
However I was able to stop the fan with the newspaper on step 4

Am I not supposed to stop it at all with the newspaper even if I push hard?