My truck is hot... too hot?

[Thomas_Magnum_'98]

Hello all. My truck has been running well ever since I replaced the timing belt, water pump, thermostat, etc. However, it seems to be running hotter than it should be. Now, my temp gauge in the cluster never raises above normal, but I've logged some data with Torque and have seen average temps around 205 - 206 F on the highway. I remember hitting 212 one day. :shocked: Now, after doing some reading, I've found that normal operating temp for these trucks is around 185 - 195 F. What do you guys think? Personally, I don't think this is going to damage the engine, but I know it can't be the best for it to be running this hot. Discuss!

Also, the water pump and thermostat was replaced around 4,000 miles ago along with new (green) coolant. Original radiator.

I know I need to change it out to red. I forgot to tell the shop when I had it done. :doh:

1999 3.4L 4WD Manual

 

[JayRolla]

Hello all. My truck has been running well ever since I replaced the timing belt, water pump, thermostat, etc. However, it seems to be running hotter than it should be. Now, my temp gauge in the cluster never raises above normal, but I've logged some data with Torque and have seen average temps around 205 - 206 F on the highway. I remember hitting 212 one day. :shocked: Now, after doing some reading, I've found that normal operating temp for these trucks is around 185 - 195 F. What do you guys think? Personally, I don't think this is going to damage the engine, but I know it can't be the best for it to be running this hot. Discuss!

Also, the water pump and thermostat was replaced around 4,000 miles ago along with new (green) coolant. Original radiator.

I know I need to change it out to red. I forgot to tell the shop when I had it done. :doh:

1999 3.4L 4WD Manual

Ive not personally experienced this but if the jiggle valve on the thermostat is clocked incorrectly it can cause a 10* variance in temp. Research thermostat jiggle valve orientation.

 

[ThorInc]

Jiggle valve at the 6 pm position will give you a 10* drop in temp (per Toyota SM); don't ask me why, it defies logic but I saw it with my 3rd gen.

 

[Brian3676]

Did you use an OEM T stat or aftermarket? I have seen aftermarket ones temps fluctuate before as there quality control is not as tight.

Also, sure you bleed all the air out? If there is any air it can also cause higher temps. That being said, those temps are really not that bad

 

[LittleCaesar]

Jiggle valve at 6 o'clock, as well as try and get as much of the air out of the cooling system as possible.....

 

[Thomas_Magnum_'98]

It's an OEM thermostat.

I will DEFINITELY check out the jiggle valve. I had the work done at an independent shop, and I'm sure they didn't realize it's supposed to be at 6 o'clock. Hopefully that will solve the issue.

I was going to flush the green rad fluid anyway, so maybe flipping the T-stat will fix it! Thanks for all the quick replies.

Is there a good procedure for getting all the air out and flushing? I heard that distilled water can be run through the system until it's clear to flush, but what about getting the air out?

Sent from my Nexus 5 using Tapatalk

 

[LittleCaesar]

Here you go, this video gives a good idea on how to flush the system, plus on purging as much air out as possible:
https://www.youtube.com/watch?v=5ysgDyea1GU

Here is the coolant funnel, worth $25 and more. I usually park on an incline and let the 4runner run for about 10 minutes when burping the system:
https://www.amazon.com/Lisle-24680-...8&qid=1470152337&sr=8-1&keywords=lisle+funnel

 

[Rock_Rat]

It's an OEM thermostat.

I will DEFINITELY check out the jiggle valve. I had the work done at an independent shop, and I'm sure they didn't realize it's supposed to be at 6 o'clock. Hopefully that will solve the issue.

I was going to flush the green rad fluid anyway, so maybe flipping the T-stat will fix it! Thanks for all the quick replies.

Is there a good procedure for getting all the air out and flushing? I heard that distilled water can be run through the system until it's clear to flush, but what about getting the air out?

Sent from my Nexus 5 using Tapatalk

You'll find a lot of threads on here in regards to coolant; green , purple, red, etc. FWIW, I had a good conversation with the Master Tech who does my work (mostly oil changes, tranny drain and fills. Also, installed my 4.88's) at Broadway Toyota about Red v. the 50/50 pre-diluted and they only use red. Unfortunately, they have seen a lot more problems with the cooling systems with the 50/50. Can't explain why. He won't use anything else in our 3rd gens. They also NEVER do tranny flushes in our rigs regardless of the mileage.

There's plenty of guys on here along with the general populace that run all types of fluid and don't have any problems. It's your call, just letting you know the conversation I had with my tech. Seems the OEM sensors and what-not is made with pixie dust in them.:shrug:

 

[kolelt]

On parkway with AC ON , on a humid and hot day. Going 70-80 mph. My temp was around 202-208. And I didn't even worry. Drive for an hour at that speed. Regular city driving. It's below 200 around 195-198. And I never worry.

 

[Thomas_Magnum_'98]

Here you go, this video gives a good idea on how to flush the system, plus on purging as much air out as possible:
https://www.youtube.com/watch?v=5ysgDyea1GU

Here is the coolant funnel, worth $25 and more. I usually park on an incline and let the 4runner run for about 10 minutes when burping the system:
https://www.amazon.com/Lisle-24680-...8&qid=1470152337&sr=8-1&keywords=lisle+funnel

Thank you for that video. That will help a ton when it's time to do the deed!

You'll find a lot of threads on here in regards to coolant; green , purple, red, etc. FWIW, I had a good conversation with the Master Tech who does my work (mostly oil changes, tranny drain and fills. Also, installed my 4.88's) at Broadway Toyota about Red v. the 50/50 pre-diluted and they only use red. Unfortunately, they have seen a lot more problems with the cooling systems with the 50/50. Can't explain why. He won't use anything else in our 3rd gens. They also NEVER do tranny flushes in our rigs regardless of the mileage.

There's plenty of guys on here along with the general populace that run all types of fluid and don't have any problems. It's your call, just letting you know the conversation I had with my tech. Seems the OEM sensors and what-not is made with pixie dust in them.:shrug:

I actually read up on this for a few hours yesterday and came to the same conclusion. The constituents of the pink ARE different from the red, and from what I understood some of the new ingredients don't play well with some of the metals in our cooling systems (lead, copper, etc.) in terms of corrosion. I'm more a mechanical guy than a chemical guy though... :nerd:

 

[Thomas_Magnum_'98]

Also, where are the engine temp specifications in the FSM? I've looked repeatedly and can't find them.

 

[kolelt]

I still can't understand this whole coolant flush stuff. Remove this, do this, do that, run this..... Can someone legit just break ur down it down step by step ?!?

 

[mtbtim]

In the hot summer California weather, I'm seeing anywhere from 188-194. Recently, driving up a long grade in 100 degree weather, I hit high 190's. If you're in the 200's with normal driving, something isn't right. Like others have noted, the culprit is probably the jiggle valve position.

Here's a video where I show replacing the thermostat that maybe will help you do the fix yourself. The thermostat replacement is near the end of the video.

<iframe width="560" height="315" src="https://www.youtube.com/embed/2nVbwe2t2T8" frameborder="0" allowfullscreen></iframe>

 

[shahsmerdis]

did you provide the parts to the shop? if it was red before and they put green that is their fault...

im curious how your temps will drop if you change the position of the jiggle valve. mines in the 200 range as well, but we have been driving it for probably who knows how long with the jiggle valve at the wrong spot. I just did a radiator swap, if this drops it by 10 degrees, ill probably go a head and redo it myself as well.

 

[Thomas_Magnum_'98]

did you provide the parts to the shop? if it was red before and they put green that is their fault...

im curious how your temps will drop if you change the position of the jiggle valve. mines in the 200 range as well, but we have been driving it for probably who knows how long with the jiggle valve at the wrong spot. I just did a radiator swap, if this drops it by 10 degrees, ill probably go a head and redo it myself as well.

I supplied all OEM parts to the shop except coolant. There was green in there before, so I don't really blame them. I'll definitely post back with the results.

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[shahsmerdis]

I supplied all OEM parts to the shop except coolant. There was green in there before, so I don't really blame them. I'll definitely post back with the results.

Sent from my Nexus 5 using Tapatalk

well looks like you gotta drain it anyway nows so no worries there. If you can find a free shipping codes toyota sells oem red coolant for as low as 18-20 dollars on toyota part stores. shipping kills it. but maybe with a large enough order you can get free shipping. Best of luck

 

[kolelt]

well looks like you gotta drain it anyway nows so no worries there. If you can find a free shipping codes toyota sells oem red coolant for as low as 18-20 dollars on toyota part stores. shipping kills it. but maybe with a large enough order you can get free shipping. Best of luck

I just picked up coolant from the dealer yesterday. It's was straight coolant and it was $22. I then went and got distilled water from shop rite. And mixed it 50/50. So I got basically 2 gallons for $22 of Toyota red coolant. I don't think that is expensive.

 

[Thomas_Magnum_'98]

It's $33 on Amazon, so that's good to know. I almost pulled the trigger on it.

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[shahsmerdis]

It's $33 on Amazon, so that's good to know. I almost pulled the trigger on it.

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my local dealer is an ass i had to pay 33 bucks. (no choice)

 

[DK327]

I will DEFINITELY check out the jiggle valve. I had the work done at an independent shop, and I'm sure they didn't realize it's supposed to be at 6 o'clock. Hopefully that will solve the issue

My T4R ran @ 202-207 with thermostat jiggle valve @ 12pm. After changing to 6pm, it's now 188-190 consistently. I recently took a long trip to SD during the heatwave where the outside temp was in triple digits and engine remained @ 195F with trans @ 177F w/ aux cooler. The culprit is most likely the jiggle valve position, as stated.