JayRolla
New member
I actually reuse the same fluid if it was just swapped. I drain, save and refill.
Also I buy Zerex Asian from Napa, only place I can find it. Its the same as toyota red. Comes premixed 50/50.
Weird coolant heating issues but not overheating?
- Thread starter JWaldz
- Start date
I actually reuse the same fluid if it was just swapped. I drain, save and refill.
Also I buy Zerex Asian from Napa, only place I can find it. Its the same as toyota red. Comes premixed 50/50.
JWaldz
Moderator
Well when you mentioned the coolant maybe being a weird mix, it got me thinking that all I've ever used is 50/50. I've never added just water to the system to "get by". I always keep 50/50 red on me in my cargo bins and it's usually Toyota brand. So, I don't know how it would be a weird mix causing the issue. With this situation I'm going to go with all new fluids just to make sure everything I'm putting in is new to cancel out possible causes. If it ends up being a bad radiator, I can simply drain and reuse at that point but a pressure test should tell me if it's the radiator before I do new fluids and a thermostat anyways.
JayRolla
New member
Okay, thats good you never added water. So im still guessing at thermostat and or cap even if just replaced. I added water before my trip because I was out of red and was lazy. Didnt have any issues. Got to drain and refill before winter. Made that mistake in my past. Was using just supercool and water wetter, not know it was a coolant and not an antifreeze at all. Replacing freeze plugs is never fun.
frodiesel
New member
I ordered a fan clutch after i saw 227 and climbing idle in the heat. Never saw it on the analog gauge. Glad i bought a scan guage and replaced the fan ckuth with amazon oem brand.
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JWaldz
Moderator
[MENTION=84120]nevada[/MENTION] & [MENTION=135660]higgy[/MENTION]
Fan clutch is Toyota brand and around 3 years old. Hard to believe it would have already crapped the bed. Plus, if the fan clutch was bad, my temps wouldn't go down when sitting at a red light, they would most likely rise exponentially. So, in my situation at say 207° if I'm sitting at a red light, depending how long I'm there, it either stays the same until I start driving again or eventually starts dropping sitting there.
Fan clutch is Toyota brand and around 3 years old. Hard to believe it would have already crapped the bed. Plus, if the fan clutch was bad, my temps wouldn't go down when sitting at a red light, they would most likely rise exponentially. So, in my situation at say 207° if I'm sitting at a red light, depending how long I'm there, it either stays the same until I start driving again or eventually starts dropping sitting there.
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nevada
Senior Member
I agree the clutch being that new, it shouldn't be bad. but parts do fail early sometimes.
what you are describing is exactly what happens when you have inadequate airflow.
it will cool fine at an idle, or low loads. once a heavier load is applied the fan is unable to move enough air, and the engine starts to heat up.
what you are describing is exactly what happens when you have inadequate airflow.
it will cool fine at an idle, or low loads. once a heavier load is applied the fan is unable to move enough air, and the engine starts to heat up.
JWaldz
Moderator
Even at heavy loads I'm still going fast enough that the natural air movement should allow for optimal cooling. Keep in mind it does this any time of the day/night. Even when it's nice and cool out. Even if I'm on the interstate, if I go up a hill that requires it to drop a gear for a while I'll start to see an increase in temp. I don't think it's an airflow problem. If I had an airflow problem I think this would be a lot worse.
JWaldz
Moderator
Try to avoid it at all costs.. Mud is no friend of mine! I'm old enough to have learned that the hard way through high school lol.
Crowcifier6
New member
[MENTION=58830]JWaldz[/MENTION] Im interested too, my 98 3RZ auto has been getting higher temps lately (200+ on occasion). I've been attributing it to the warming ambient temps outdoors, or heat sink effect (shut down at operating temp, started again within 5 mins and temps are high), but I'm curious if the thermo will cool it down a bit. Mine is most likely stock.
I replaced leaky lines to rear heater, radiator and hoses, water pump and gasket, everything but the thermostat (in the parts box, just got waylaid). I'm guessing that is what's going on with mine.
I replaced leaky lines to rear heater, radiator and hoses, water pump and gasket, everything but the thermostat (in the parts box, just got waylaid). I'm guessing that is what's going on with mine.
Thermostat
I had issues with higher than normal temps after having a mechanic do a timing belt change, which includes water pump and thermostat as preventive maintenance.
Before the timing belt change the temp ran about 190F (88C) with a Scan Gauge II device, 'cause the temp meter isn't working, which is normal for a 2000 4runner. After the service the temp would climb to the mid to high 190's, and on an incline would get even higher. Living in WV there aren't many flat roads so I was constantly driving with OD off, and on many occasions having to pull the shifter into 2nd just to keep the temps in check.
Complained to the shop about the higher then normal temps, but they dismissed it, saying anything under 200 wasn't considered running hot. He was used to Chevy's, which run about 215F. They did change the thermostat, but no change.
Finally had enough, so I removed the thermostat completely and took it on a test run on my favorite 8 mile uphill stretch, and temps never climbed above 178F.
Ordered a OEM thermostat from Amazon and when I got it I noticed a huge different between that and the generic one. It is larger and beefier, and the package said high flow thermostat.
Installed it and problem solved.
I had issues with higher than normal temps after having a mechanic do a timing belt change, which includes water pump and thermostat as preventive maintenance.
Before the timing belt change the temp ran about 190F (88C) with a Scan Gauge II device, 'cause the temp meter isn't working, which is normal for a 2000 4runner. After the service the temp would climb to the mid to high 190's, and on an incline would get even higher. Living in WV there aren't many flat roads so I was constantly driving with OD off, and on many occasions having to pull the shifter into 2nd just to keep the temps in check.
Complained to the shop about the higher then normal temps, but they dismissed it, saying anything under 200 wasn't considered running hot. He was used to Chevy's, which run about 215F. They did change the thermostat, but no change.
Finally had enough, so I removed the thermostat completely and took it on a test run on my favorite 8 mile uphill stretch, and temps never climbed above 178F.
Ordered a OEM thermostat from Amazon and when I got it I noticed a huge different between that and the generic one. It is larger and beefier, and the package said high flow thermostat.
Installed it and problem solved.
gamefreakgc
Elite Member
Glad it helped but your mechanic is right. I've climbed as high as 230 degrees briefly in mine (don't ask) with no ill effects. On that same engine, I'd see 200's regularly in summer heat with A/C on. The coolant is under pressure and has a boiling point of over 235 degrees depending on coolant mixture. 190's isn't really that much at all. GM's do perch precariously hot though since it only takes a bit hotter temps to start doing damage and doesn't give much time to react.
JWaldz
Moderator
[MENTION=506139]chewie[/MENTION] [MENTION=143878]Crowcifier6[/MENTION]
I think it was beginning stages of headgasket failure. Not to mention my radiator developed a leak that was untraceable as it wasn't enough to hit the ground. Throughout the next year or so the engine developed other problems, the headgasket finally went, and the engine was toast. I will say, while yes low 200s certainly isn't an issue, per say, but consistent temps in that range should be addressed. It could have long term effects. The engine I put in along with a new radiator, I hardly ever see 190, and I drive it every day.
I think it was beginning stages of headgasket failure. Not to mention my radiator developed a leak that was untraceable as it wasn't enough to hit the ground. Throughout the next year or so the engine developed other problems, the headgasket finally went, and the engine was toast. I will say, while yes low 200s certainly isn't an issue, per say, but consistent temps in that range should be addressed. It could have long term effects. The engine I put in along with a new radiator, I hardly ever see 190, and I drive it every day.
I did timing belt/water pump job back in March which included Oem thermostat. Unaware of any issues until 2 months later-
With higher temps outside, I was idling in a parking lot for about 15-20 mins after driving 20 mi on interstate. As I was leaving I noticed the needle was about 3/4 up and thought it needed air so I got moving and it settled down.
At this time I began monitoring the coolant temp via Fixd reader and app which was showing me an average operating temp of 204 with readings as high as 216 in stop and go and up hills.
Research led to the fan clutch test, which failed. I replaced, I also flushed out green coolant and switched to Toyota red.
Back on the road this week, the highest temp I’ve seen is 208 and averaging 199-204. Better but not satisfied as I believe that’s too hot for regular driving here in the low country and it’s not really even hot out yet. I’ll likely see another intermittent overheating episode with the right combo if nothing is done.
I’ve read about the jiggle valve NEEDING to be a six o’clock and fixing similar symptoms. Also read about testing the ECT sensor which may be giving a false temp, and the possibility of a faulty thermostat which apparently happens a lot.
I’ve ordered a new OEM thermostat and will test it before pulling the current. Will also check current thermo for jiggle valve position and, if correct, will test that one for opening at correct temperature.
With higher temps outside, I was idling in a parking lot for about 15-20 mins after driving 20 mi on interstate. As I was leaving I noticed the needle was about 3/4 up and thought it needed air so I got moving and it settled down.
At this time I began monitoring the coolant temp via Fixd reader and app which was showing me an average operating temp of 204 with readings as high as 216 in stop and go and up hills.
Research led to the fan clutch test, which failed. I replaced, I also flushed out green coolant and switched to Toyota red.
Back on the road this week, the highest temp I’ve seen is 208 and averaging 199-204. Better but not satisfied as I believe that’s too hot for regular driving here in the low country and it’s not really even hot out yet. I’ll likely see another intermittent overheating episode with the right combo if nothing is done.
I’ve read about the jiggle valve NEEDING to be a six o’clock and fixing similar symptoms. Also read about testing the ECT sensor which may be giving a false temp, and the possibility of a faulty thermostat which apparently happens a lot.
I’ve ordered a new OEM thermostat and will test it before pulling the current. Will also check current thermo for jiggle valve position and, if correct, will test that one for opening at correct temperature.
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