The scan gauge, yes. Plus the factory needle which work off the same sending unit. But the temps go with how hard the engine is working. It will even drop two degree's when pulling up hill and the engine down shifts. I also found the sweet spot of about 3700-4000 RPM it seems to make the most power and run at a fair 216-220 when pulling a hill.
2005 V8 Overheating.
- Thread starter jdemello
- Start date
The scan gauge, yes. Plus the factory needle which work off the same sending unit. But the temps go with how hard the engine is working. It will even drop two degree's when pulling up hill and the engine down shifts. I also found the sweet spot of about 3700-4000 RPM it seems to make the most power and run at a fair 216-220 when pulling a hill.
Jason,
I have had a similar issue in my silver 4runner when I was pulling my little 3k expo trailer (loaded).
I called Rickie (Buddy from Toyota) and he said it can be because we do not have a tow haul button. I am paraphrasing, but he said the tranny is constantly shifting in and out of overdrive (4th) and it causes it to heat up, and because our tranny cools via the radiator it is causing the radiator to get super heated and overheat the engine.
He said the tranny can make the radiator so hot it can cause serious problems. As far as it do it when you are not towing, it is still likely your transmission getting hot from all the high rev shifting.
Put an additional tans cooler on the truck, help cool it off and add more fluid to the system.
FYI, I did not modify mine at this point because I seldom tow with it.
I have had a similar issue in my silver 4runner when I was pulling my little 3k expo trailer (loaded).
I called Rickie (Buddy from Toyota) and he said it can be because we do not have a tow haul button. I am paraphrasing, but he said the tranny is constantly shifting in and out of overdrive (4th) and it causes it to heat up, and because our tranny cools via the radiator it is causing the radiator to get super heated and overheat the engine.
He said the tranny can make the radiator so hot it can cause serious problems. As far as it do it when you are not towing, it is still likely your transmission getting hot from all the high rev shifting.
Put an additional tans cooler on the truck, help cool it off and add more fluid to the system.
FYI, I did not modify mine at this point because I seldom tow with it.
The stock 4Runner V8 is rated to tow about 7,000 lbs. But your 4Runner isn't stock. You've added a ton of weight to it -- 35s, skid plates, roof rack, etc. You've also added a whole lot more aerodynamic drag and more friction from the tires. So your truck already needs to use a whole lot more power to go 60 mph than stock even without a trailer. But now you are towing a trailer near the max rated weight in very high temps.
So it doesn't really surprise me that the truck is overheating.
So it doesn't really surprise me that the truck is overheating.
I'm going to do that anyways because it's not a bad addition. And what you are saying makes sense. I've heard this from some one else as well.
I understand that but I've towed from SoCal to Texas and back with more weight in the trailer then this past weekend and more hills and the temp didn't get as high. But I was running a slightly lighter and narrower tires.
I had a long talk with a good mechanic friend of mine, He assured me that 200-220 is pretty normal when considering the outside conditions and towing. He said his Chevy does about the same temps and he doesn't start to get concerned till it reaches 240*.
He did say it wouldn't hurt to vent out the engine bay, trimming the inner fender skirts to let more heat escape. This kinda makes sense because I have recently added anther 2.5in shock in there along with two more reservoirs blocking almost all that area.
We covered, possible air bubble in the system and he said that would over heat much faster, head gasket I'd see other signs, timing would cause it to run way rough, all my other stuff has been replaced. He did mention that sense i went with a after-market fan clutch that it might be good to replace it with a Toyota one but also said that wouldn't make much difference at speed.
I know running bigger tires, after market bumpers, sliders, roof rack and other goodies isn't going to help but I had most of that previous, to this problem.
I'm going to order some 4:88 gears and drop the axle ratio one more time, I'm already at 4:56 but I want to help the pulling anyway I can.
I know I'm pushing the limits of the truck, it actually pulls pretty good and does a decent job, I think if I just mind the weight a little closer when I'm loading it down, remove my roof light bar and spare tire when towing and vent out the engine bay a little it will be better. I'm also going to put a bigger transmission cooler in there.
I've got 22k miles on the truck just towing and I know it means I'll need a transmission rebuild sooner rather than later and most likely the engine as well. I'm really kinda curious how long it will last like this. I do a trans flush once a year so about every 15-12k and the engine oil gets done every 3k or if I'm towing two long hauls in a row I'll change it in-between even if it's only 1000-1500.
Yes I've considered a bigger truck and I've considered getting anther diesel. But for my business this combo seems to be working well. I don't think a full size tundra (esp since we don't make much for them) would work as well to show case our products, but I haven't ruled that out either. I've even contemplated swapping a late model 5.7 drive train. Unfortunately I don't think the money spent would net anything more than a really powerful small truck that gets even worse mpg.
BlackWorksInc
New member
If I rememeber right, the owner's manual says to not tow in D (Overdrive) but in 4 to aleviate this issue. The V8's have a stand alone transmission cooler located in the lower driver's side half of the radiator. I could see it heating up the air going into the radiator some under load... but do you really think its enough to cause the vehicle to overheat? Though it wouldn't hurt to beef up the transcooler and maybe relocate it at this point.
The operating temperatures seem somewhat reasonable given the outside heat and load you're putting on the engine, but I can understand the desire to be closer to the nominal range.
NJshadow93
New member
I don't have much to say except that I think the towing capacity is more based on the hitch and wheelbase. I think the engine and transmission can handle much more weight. Also, when you tow, do you take it out of overdrive? Sorry if I missed that if you mentioned it already, but I heard that taking it out of overdrive when towing is a must.
EDIT: [MENTION=66389]BlackWorksInc[/MENTION] beat me to it lol
EDIT: [MENTION=66389]BlackWorksInc[/MENTION] beat me to it lol
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Mine's considerably lighter at 3K+ but I have to deal with the Rockies and high passes of 14k feet or so. Keeping it out of OD helps keep the hunting for gears and the temp down too.
I wonder about the tranny temps too, I have no idea where they should be, do you?
I generally don't keep it out of overdrive, with the re-gear on the axles it doesn't hunt that much (IMO) but I guess that could be a culprit as well.
I do believe (but could be wrong) that the trans goes through the radiator and then into the external cooler.
I'm going to put a bigger external cooler on there. I also ordered a factory hood scoop and I'm going to work on glassing the opening today so it looks decent. That should help the cooling the engine as well. I'm also going to take a close look at the engine bay and see what else could be causing it.
The thing that really concerns me is that completely empty it's still getting warm in comparison to my 2001 tundra. I recently took it on a road trip through the desert to AZ and back and it never got above 198 and that was only once going through the hills with the ac on. Most of the time it was 185-190 right on the money. Again though my 4runner is not stock soooo.
JB.
New member
jdemello,
On a side note, does the stock dash temp gauge reflect the water temp increases evenly and predictably? I ask because I've never seen mine budge past its normal set position and I recall someone at 120 once saying that it takes a lot of temperature rise past normal to get any movement in it.
On a side note, does the stock dash temp gauge reflect the water temp increases evenly and predictably? I ask because I've never seen mine budge past its normal set position and I recall someone at 120 once saying that it takes a lot of temperature rise past normal to get any movement in it.
JB.
New member
Thanks.
I'm interested in knowing this so I want to make sure I'm clear on it.
So I shouldn't interpret the needle in its standard spot at full operating temperature as an indication of exact temperature based on precise position. Instead, the standard needle position embraces a wide range of temps that will only move it if they are exceeded?
No it moves but is hard to tell. From the start of the grey zone I'd guess it's about 170ish to the top is about 225ish. Those are rough and may very. But also not that it's hard to tell when it moves. I have hit 216 and can't tell the difference between that and 200 or even 190. It doesn't seem very drastic till it gets above the grey zone.
It does say that. People tow in OD anyways when the transmission doesn't hunt, but what they are not thinking of is that the additional RPM gained by towing in 4th spins both the water pump and the transmission oil pump faster, effectively moving heat away quicker.
-E
The fact that it cools down when you stop would lead me to believe that you could benefit greatly by increased air flow. When you are at speed, your fan is not effective; it is all about the air flow. Obviously the additions have increased your cooling demands so the cheapest way before you increase the size of the radiator or add additional coolers would be to increase the volume of air. Your bumper may not channel the air properly or may not be open enough. It may not just be the inlet that is the problem; the skids could be restricting the air exiting
It could be the combination of both. I'm finishing up the hood scoop today and I bought a really nice trans cooler. I'm going to try those two things things this weekend when I tow to Parker.
I did add the full skids on the last trip so it's a possibility those caused some more heat too? I'm pulling a lighter load this week too, pretty much a empty trailer. and I'm removing the light bar and spare tire from the roof.
