I was driving down I-24 pulling a U-Haul trailer the other day when my '97 80 overheated. I had driven from Minnesota to Tennessee with the trailer and hadn't really had any problems. However, going up this really long mountain pass, the truck just kept getting hotter. I was going about 25mph and had turned the heater on. Pulled of to a rest stop to let it cool, but it would no longer cool down at all and would just steadily heat up again. It wasn't leaking any fluid, though it did have steam coming out of it somewhere in the rear, driver's side area. All the belts were fine and the radiator didn't explode. I checked the level before I left Minnesota and twice along the way and it was fine. Any ideas what could have happened?
Overheating Problem
- Thread starter Pete483
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Give us some info on your 80- how many miles? Mods?
- Has the rig had regular coolant flushes with no mixing of red/green coolant?
- Check color of coolant in overflow- is it red, green, or black?
- Check flow through radiator (could be clogged)
- Check operation of radiator fan clutch (could be working improperly)
- Replace radiator cap
- Replace thermostat
This is becoming all-too-common!
- Has the rig had regular coolant flushes with no mixing of red/green coolant?
- Check color of coolant in overflow- is it red, green, or black?
- Check flow through radiator (could be clogged)
- Check operation of radiator fan clutch (could be working improperly)
- Replace radiator cap
- Replace thermostat
This is becoming all-too-common!
Hi Pete, welcome to the forum.
There is plenty of info on overheating here and we are just riding a wave of posts on Head Gasket failures. Sobering reading material.
You'll need to give more info if you want people here to be able to help (not that not having it would stop many here
). Like the condition of your cooling system etc.
So what happened after the rest stop?
There is plenty of info on overheating here and we are just riding a wave of posts on Head Gasket failures. Sobering reading material.
You'll need to give more info if you want people here to be able to help (not that not having it would stop many here
). Like the condition of your cooling system etc.So what happened after the rest stop?
rear drivers area I'm thinking PHH. Try search on this. There is an excellent replacement proceedure on www.sleeoffroad.com If I say so myself.
- Thread starter
- #5
Rig had 134K miles, but was rebuilt about 15K ago (cooling system wasn't). It has OME springs and such, but still has stock tires. All green coolant and the fan was working fine. My thought was that the radiator had a heart attack of sorts. I wasn't able to check the flow though. I had to abandon my truck and rent a uhaul to keep moving with my trailer. I'm in the military and am changing stations so I had to keep moving.
As far as the condition of my cooling system, I would rate it poor to very poor. Oh, do you mean prior to this?
The drive down it was running hot enough that I didn't want to use the AC, but I figured that had more to do with the 90-100 degree weather and the 9,500 GVWR I had. Didn't have any coolant leaks before that nor any problems with it running hot.
After the rest stop, it would start fine, but would slowly start to overheat again at idle. I left the rest stop to see if a little air flow would help being that I was at the top of the mountain, but had to get off at the next exit 1/4 mile down the road as it was getting hot again.
My thought is a clogged radiator, but I can't figure out where this steam was coming from. It looked like it was coming out from somewhere on the DS rear of the engine, but I couldn't see exactly where.
That's about all the info I have. I'm thinking this is going to cost me, mostly because I had to leave it in Tennessee.
As far as the condition of my cooling system, I would rate it poor to very poor. Oh, do you mean prior to this?
The drive down it was running hot enough that I didn't want to use the AC, but I figured that had more to do with the 90-100 degree weather and the 9,500 GVWR I had. Didn't have any coolant leaks before that nor any problems with it running hot.After the rest stop, it would start fine, but would slowly start to overheat again at idle. I left the rest stop to see if a little air flow would help being that I was at the top of the mountain, but had to get off at the next exit 1/4 mile down the road as it was getting hot again.
My thought is a clogged radiator, but I can't figure out where this steam was coming from. It looked like it was coming out from somewhere on the DS rear of the engine, but I couldn't see exactly where.
That's about all the info I have. I'm thinking this is going to cost me, mostly because I had to leave it in Tennessee.
Steam from "driver's side rear of the engine"? In that case, landtank has it nailed- your PHH ("Pesky Heater Hose" AKA "rear inlet heater hose" per factory service manual) has blown. Common failure, which is why it is good PM every 60K with the stock hose or longer with a silicone hose (search for threads and see FAQ)
See this link for details (thanks to sleeoffroad.com):
http://sleeoffroad.com/technical/tz_heater_hose.htm
See this link for details (thanks to sleeoffroad.com):
http://sleeoffroad.com/technical/tz_heater_hose.htm
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do you have your truck now, or is it still in TN.?
i'm in CA but... if i were in TN, i'd help a serviceman out by giving you my bolted up fan clutch, delivered and installed with a side of system flush. i'd even sport you the extra thermostat and gasket i've got sitting out in the top box.
for a couple of anecdotal stories about being in the military, i'd even replace your PHH(as long as you kept them funny and they lasted the two hours it took me to replace the one on my roommates '96)
anyone in the area can help this guy out?..
i'm in CA but... if i were in TN, i'd help a serviceman out by giving you my bolted up fan clutch, delivered and installed with a side of system flush. i'd even sport you the extra thermostat and gasket i've got sitting out in the top box.
for a couple of anecdotal stories about being in the military, i'd even replace your PHH(as long as you kept them funny and they lasted the two hours it took me to replace the one on my roommates '96)
anyone in the area can help this guy out?..
Pete or Grouseman - I'm in Knoxville and have a thermostat on hand if it would help. I'm sure parts guys in Nashville do to, but thought I'd offer. Any other help I can provide let me know they haven't called teachers back to school just yet so I may be able to help mid day/weekday stuff if you were headed East and not Memphis/Millington.
FatDaddy,
I pmed him and haven't gotten a response back yet. Not sure where his truck is. Hopefully he will check the board soon. I not much help mechanically as Gumby will verify but I know where the PHH is, and other related items.
Grouseman
I pmed him and haven't gotten a response back yet. Not sure where his truck is. Hopefully he will check the board soon. I not much help mechanically as Gumby will verify but I know where the PHH is, and other related items.
Grouseman
If he was on 24 should obviously be near Nashville but those mtn. passes sound like up my way toward Cookeville coming up off the plateau. Anyway I'm no ace wrencher either but willing to give this guy a hand-sounds like a tough spot. I'll keep watching this thread if he doesn't use mud often probably not familiar with PM stuff, just a guess.
I replaced my PHH less than a year ago. Just now driving home on the first cold day, I started getting steam inside, pulled over to find steam coming from basically the PHH area. I have never seen my temp guage anywhere other than dead center until now. I used the wits end kit. My heater was not on. Is there another heater hose near there? Is there another thing to look at or should I just expect the PHH failed?
No, as you can see in the previously attached picture, the nipple is much smaller. It it also a preformed hose that will be an OEM part.
If indeed the problem is that small diameter “FHH” coolant bypass hose and it’s leaking near the clamp at nipple on the side of the head you may be able to cut the end off the hose eliminating the leak and then put the hose and clamp back on the nipple and keep going down the road until you can get the new hose.
As mentioned earlier, it may be available only from Toyota but I can’t say for sure.
As mentioned earlier, it may be available only from Toyota but I can’t say for sure.
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FHH is 5/16” or 8mm. Mine is replaced with bulk hose, go a little longer on it and the throttle body can move a little further out of the way for future service in that area of the engine.
It was the FHH. cut it shorter since I only had 3/8 on hand.
Anyone recommend a full hose kit? I have the three radiator hoses. Like to get them all done for peace of mind. Thermostat as well. Also, I have seen mention of rear heater hose delete, any thoughts on that subject appreciated. Thanks!