Last week my 89 fj62 was running a little hot on the way to work. Not quite to the red, but close. I stopped and added coolant to the resevoir, which was nearly empty and thigs seemed to be fine for a few days. The truck started running hot again. This time the resevoir was still full. I noticed the truck cooled to normal temps at 45mph and only heated up when stopped or moving slowly. Although the resevoir was full I was able to put in about a half gallon of fluid directly into the radiator when it cooled off. Now 2 days later, I drove it home and it pegged in the red zone. It didn't cool at speed at all. Again the resevoir was full and I was able to add collant directly to the radiator when it cooled. I can hear a sizzle coming from behind the fan, but no water seems to be leaking on the ground when I'm stopped. Any Ideas?
Overheating problem Any ideas?
- Thread starter mrmoonlight
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mrmoonlight said:
some possibilities:
1) fairly easy to fix: bad waterpump, bad thermostat, bad fan clutch, bad radiator hoses. If there is a leak somewhere, you should be able to see it by going under the truck and searching for crusted salty yellow or red stuff.
2) Harder and more expensive to fix: cracked head, bad head gasket. If that is the case, you should have coolant in your oil, and that is easily visible. The oil will no longer be transparent, but milky.
either way, it needs to be fixed quickly, since 2 will result from 1.
jan
- Thread starter
- #3
I haven't looked to hard underneath, but there is some green splatter along the top hoses that looks like it is being flung off the fan. The oil looked fine as of my last gas stop. Normal color and consistancy on the dipstick. Any indicators to look for to determine which part t-stat, pump ect is the culprit or should I just start replacing cheapest first.
mrmoonlight said:
how many miles on the truck?
If there is green spaltter, you have a leak somewhere. I usually do a job complete, but that is up to everyones taste. Here is what I would do: make sure the radiator is not leaking. Then change radiator hoses, thermostat, radiator cap, and waterpump. you are looking at ~200US, and a few hours of labor. Nothing is hard to do there.
Anyway, I am paranoid with the cooling system, since I don't want to get stuck in the desert overheating somewhere in mexico
wingysataday said:
not if he sees green splatter, then there is a leak somewhere.
No question you need to get this fixed, or the consequences could be expensive. A leak could be the total reason for what you're describing though. A leak lets fluid out and air in. Air is a great insulator, that is, it does a lousy job in conducting heat - air in a radiator won't cool well at all.
Find the leak, fix it, get all the air out of your system (do a search on burping). If you still get overheating, then the posts above have some good suggestions.
One thing on leaks, make sure all the hose connections are tight...I bet I'm not the only one who's had to learn this lesson...
Find the leak, fix it, get all the air out of your system (do a search on burping). If you still get overheating, then the posts above have some good suggestions.
One thing on leaks, make sure all the hose connections are tight...I bet I'm not the only one who's had to learn this lesson...
Check the water pump. Should have coolant seeping from a weep hole on the top. If it is the pump consider replacing the water pump and fan clutch as an assembly. Not much more than the water pump only - a easy "while I'm at it" project.
mrmoonlight said:
The fan clutch is mounted to the front of the waterpump. It's function is to engage/disengage the fan as necessary. It's heat activated - when the engine gets hot enough, the fan clutch engages, turning the fan, helping to cool the engine. Just the opposite when the engine cools off. Idea is to have cooling when needed, but save fuel when not needed. While they do fail eventually, the OEM ones are remarkably durable and reliable.
Three suggestions(besides what everyone else has said): 1) Don't drive it with the temp gauge in the red
2)Be a detective...find out where the "hissing sound" is
coming from. Use a piece of hose or one of those $10
automotive stethoscopes.3)If it's the radiator that's leaking,consider simply replacing it w/ a new aftermarket unit. If you live in a high labor-cost area like me, cost could be about the
same as having the 15-20 year old one "serviced".
2)Be a detective...find out where the "hissing sound" is
coming from. Use a piece of hose or one of those $10
automotive stethoscopes.3)If it's the radiator that's leaking,consider simply replacing it w/ a new aftermarket unit. If you live in a high labor-cost area like me, cost could be about the
same as having the 15-20 year old one "serviced".
- Thread starter
- #14
Upon further review it seems the radiator is leaking. Anyone know where I can get a good replacement? I've heard performance radiators are good. Any experience with these or any other aftermarket radiators. Know any good suppliers?
No personal experience w/performance, but good references on this board for their products/pricing.
Congrats on tracking down the source of the problem.
Something to consider, since you're going to have the rad out, you might want to do a thorough cooling system flush. Get all the accumulated crap out of there. There are posts on how to do this. Also, it's easier to change hoses while the cooling system is empty! So, also consider replacing any that are questionable. T-stats are cheap, it's almost always a good idea to replace them. Finally, make sure you get a new OEM rad cap - lots of wierd cooling sys issues from sub-par caps.
Congrats on tracking down the source of the problem.
Something to consider, since you're going to have the rad out, you might want to do a thorough cooling system flush. Get all the accumulated crap out of there. There are posts on how to do this. Also, it's easier to change hoses while the cooling system is empty! So, also consider replacing any that are questionable. T-stats are cheap, it's almost always a good idea to replace them. Finally, make sure you get a new OEM rad cap - lots of wierd cooling sys issues from sub-par caps.