What's your ave coolant temp?

Just replaced the timing belt, water pump, belts and thermostat with an OEM 82C / 180F thermostat on my 2003 3.4 ext cab 4x4 with 109k auto trans and trans cooler. Filled with prestone 50/50 and verified the system is properly filled through several run-ups and cool-downs.

My temp is averaging 198F now. With the old thermostat (the original oem thermostat) I used to see 185F, possibly 190F on a hot day idling. I've bumped 215F towing in mid-summer, now I'm wondering what I'll see when towing with the new thermostat - even that temp though did not budge the stock temp gauge. So maybe this is within limits.

I've seen guys brag about 160F and 200F alike. What's too hot? What's too cool?

Opinions? I now you'll have 'em....

 

Only opinion I have is just from reading a lot on here. Was the jiggle valve installed in the correct orientation? I know if you accidentally reverse it you get higher temps.

 

Agree

 

Don't get all wrapped up about the exact temp.

What's the temp needle on the dash doing? Nothing? You're fine.

I've gotten 230ish in my 5th gen 4Runner while towing a 4000# trailer in August up steep hills (like 1st gear steep hills). My warning light never came on. Years ago I was towing a smaller popup tent trailer up some hills and I could feel the trans heat thru the floorboards and the warning lights never came on. The fluid was fine, too (no burnt smell).

Warning light comes on = too hot. Warning light doesn't come on = not too hot.

 

Yes, installed jiggle valve on top.

 

This makes sense to me. My water temp gauge has never budged and the AT light has never come on. So one would logically assume that the temps I'm seeing are within the manufacturers limits.

I was just curious what others thought.

 

The jiggle valve thing on the t-stat is definitely something to consider, but as long as that was installed in the correct orientation, you should be fine. But even if not, as far as I know, it's only worth a couple of degrees temp difference. Still not enough to make your engine blow up, lol

 

Jiggle valve should be installed at the 6 o’clock position. Facing downwards, that’s definitely gotta be your problem.
I don’t agree with Jbrandt, if you’re getting up into 230s, just because you’re dash doesn’t say anything doesn’t mean it isn’t bad for the engine. It’s not going to kill it if it only happens once, but having aluminum heads, sucks considering How easy they can be warped by heat. I was running close to 200 before doing my timing belt and water pump and the jiggle valve was sideways around 4 o’clock from whomever did it before me and after reinstalling it at 6 o’clock position my temp is down to a consistent 185 maybe 190 tops if it’s really hot in slow traffic

 

188˚ is what I see normally, just had my water pump and timing belt done as well.

I run a Scangauge and keep an eye on it often, on a normal day (summertime in Socal) it's at 188˚-190˚ driving around town or cruising on the freeway. Only time I see it creep into the mid 190s is going up a freeway grade in higher RPM. Long grades with the truck weighed down with gear, I've seen it go up to 207˚ but never higher than that.

I would check the jiggle valve as suggested

Also should mention I have a manual trans, autos tend to get hotter which effects the coolant temp as well.

 

I was working the shit out of my 4runner when the trans temp hit 230, I don't know what the coolant temp was since I wasn't really tracking it. But the needle didn't budge at all, meaning I wasn't close to overheating. Yes, sustained high temps could be a sign of something wrong, even if they don't trip the CEL, but I'm pretty confident the engineers wouldn't set the CEL threshhold so high that you risk warping your heads without the CEL coming on. That seems like a serious liability on their part.

Coolant temps are highly variable, and even under "normal" driving conditions will spike for short periods of time. This is totally normal and nothing to worry about. This is why the Toyota engineers decided to use an "idiot light" instead of a true temp readout on the dash.

I constantly see posts from people who just installed a OBDII scanner to track their temps, and freak out because their needle never moves but the temps bounce around, so they think something is broken or their truck is about to explode. It's actually by design. The needle will only move once it's reached some threshold that the engineers have determined is a problem. Then it warns you.

 

Jiggle valve goes at the bottom for some odd reason, I know I know, but it’s all over the forum with verified results, I’d pop the cover off and rotate that bad boy.

My grandfather who used to own a ford dealership always said the hotter an engine can run without burning up the better.. I don’t agree with his statement, but there is certainly a school of thought out there and as with most ideologies there is likely merit to go along with it; I just like my temp needle staying still and staying in the middle.

 

I have a Corolla 170 thermostat that fits in perfectly for the 3.4, you could try this thermostat it’s OEM from the dealership and it will drop your temperatures, you don’t want to go to high heat wise just because you have aluminum heads and if they get too hot they will pop your head gasket.
Jigger valve down.
I run in the 180 range but I do have a larger radiator even when 100 degrees outside

 

I’m always a constant 193-195 according to the scangauge with original coolant at 114k

 

Just because I was reading this, and was confused, I checked the manual. For the 2RZ and 3RZ, the jiggle valve appears to go up. For the 5VZ it goes down.

Does that jive with what everyone else thinks?

 

On 3.4 jiggle valve is to be oriented at 6 o'clock.
On the 2.7 jiggle valve is oriented at 12 o'clock.
It's in the FSM. And it's proven/shown/tested to run 8-12 degrees hotter when jiggle valve is installed in incorrect position.
Yes it matters. Yes 10 degrees matters.

 

Ahh I didn’t realize you meant the trans temp, which personally 230 for a trans in my opinion is still too hot, have you looked into an external trans cooler? Not sure how often you tow or have seen your temps that high or if you possibly already have a trans cooler but I’d recommend this one if so. After doing some research before and reading gearcruncher a thread on autos this is the cooler that was recommended to be the best. The one I bought before deciding to do a manual swap.
https://www.amazon.com/gp/aw/d/B005XZXB1M?psc=1&ref=ppx_pop_mob_b_asin_title

 

It's definitely on the list for the 4Runner. I've had one on my Tacoma, seen here, since ~2010.

The 230 was a 1st gear hill, in August, outside of Bishop CA heading up to a campground called Four Jeffrey with my Winnebego travel trailer. It was by far the most extreme hill I've towed my trailer on, and I haven't seen temps near that high since then. I gained some (relative) confidence after that hill as I wasn't getting temp warning lights, and I checked the trans fluid after that and it was fine (no burnt smell). Like I said, a trans cooler is on the list, just haven't gotten around to it yet.

 

Right on, Dude your paint looks new lol, have you had it clear coated or is it original?
Impulse red?

 

This! Jiggle valve at 6 o'clock. I've verified this twice. First time I changed the t stat, I had it at 12 o'clock as its what the Haynes said. Ran a bit hot per the scan gauge, did some digging and found the 6 o'clock on the FSM. Flipped it and fixed it.

Second time was after the dealer did a timing belt, seals, pulleys belts water pump...yadda yadda. Got her back and she was running hot. I was like "No way did they do the jiggle valve up!" Pulled it apart and they sure as shit did. I flipped it...and fixed it.

It goes down.

Oh and my temps are 191 to 193 winter and summer respectively...

 

haha, this pic is a few years old, my paint doesn't look like this. I really don't take care of it that much. I don't think I've EVER waxed it except for the few year I owned it (bought it in 2005).

In fact, the bedsides are pretty F'ed up. I did some DIY bed liner stuff over a decade ago, and the clear coat eventually started pealing off at the seam of the bedliner. In the last 6 months or so, I sanded it down (sort of) to get rid of the flakey bits and rattle canned some clear coat to keep it from pealing more. Unfortunately, the sanding got rid of some of the paint, too, not just the clear coat.

But, it's a trail truck, so I'm not taking it to any cars shows anytime soon, lol...