overheated again

[zadam123]

some of you may have read my old post on my overerheating porblem if not here is a summery.

my car overheated and started leaking antifreeze so i brought it to the mechanic and he did a pressure test and it was leaking from the thermostat housing. he fixed it and put a new thermostat in. then it overheated again but there was no leaks this time. he said it was my clutch fan (my fan was spinning normal to me but im not a mechanic ) so he replaced it with a aftermarked on which does spin much faster and when you hit the gas it sound like a semi truck now. I though my probmems were done but here is the tricky part. it only overheats now on long drives (over 40 minutes) and only when the weather is above 85.

Yesterday i dorve to my friends house it was around 85 in ny i keeept an eye on the temp guage and after around 40 minutes of driving arond 65mph in no traffic and no ac on it started going up , i turned on the heat to help but didnt help it ran up to the top line. i pulled over and let it cool down for 15 minutes and continued my drive and after another 15-20 mnutes of driving it started getting hot again. . on lmy night drive home it was much cooler out like 70 deg. i made it home 1hr and 10 minutes without it getting hot.

The mechanic is saying it may be the water pump. is it possible? I hate playing these guessing games they already cost me over 600. could it be a bad thermostat he gave me? could it be the radiator?

[Y33TREKker]

What is your current antifreeze-water ratio? It can easily be checked with one of those little floating ball testing tubes (the more balls that float = the better the protection in both hot and cold weather).

That may be off-base since the overheating has happened both before and after the service work, but it's something simple that can be checked and changed if it's the cause.

[Marlin]

What is your current antifreeze-water ratio? It can easily be checked with one of those little floating ball testing tubes (the more balls that float = the better the protection in both hot and cold weather).

That may be off-base since the overheating has happened both before and after the service work, but it's something simple that can be checked and changed if it's the cause.

Clogged radiator/and or fins could also do it in addition to the water pump. I had mine flushed, it had some nasty stuff in there.

[Luna X]

Was the fan clutch ever replaced?

I had an overheating prob when I bought my VX this year... So, by using this site, I found a recommendation to replace the clutch. $70 and 30 mins of my time, and the temp has not once gone above normal.


Sometimes I wonder about the headlight seals we have... I'm sure they help in keeping out dirt and water, but I feel they may be overkill for typical street use. Just like our Rally Inspired suspension.
I took mine off in preparation for clearcoating the headlights, and now I'm leaning toward NOT installing the new ones... I believe the engine compartment needs a little air movement to help in dissipating heat.

[Marlin]

. I believe the engine compartment needs a little air movement to help in dissipating heat.

True, thats why my hood scoop is functional, I actually cut a hole through the insert and the hood. You wouldn't believe the heat you can see coming out of the vent.
The torque cool fan clutch helps as well.

[zadam123]

radiator was flushed out when the fan clutch was done and when the theromostat housing was done. my question is why dont it overheat faster? if im driving for over 30 minutes with no problem at all why all of a sudden does it go up and whenit goes up it goes from 1/4 to the first line in like 15 minutes. also with the new fan clutch spinning like crazy and 70 mph winds going through the car shouldnt that keep it cool?

is there a way to test the waterpump to see if its good? only problem is that i have to drive the car for over 40 minutes and get a over 85 degree day out which might be a problem since its gettin cold out again

[zadam123]

also running anitfreeze only to my knowledge . they put the stuff in

[Triathlete]

If they put straight anti freeze in the mechanic should be shot...it should be a 50/50 ratio of anti freeze and water.
And yes I have seen new thermostats go bad. But it could be the pump also. A good shop should be able to test the water flow of the cooling system which can help narrow it down.

[zadam123]

forgot to mention i sometimes also smell antifreeze in the car even when its not overheating. dont know why?

[Triathlete]

Generally if you can smell anti freeze it means there is a leak. It may be a very small one. Also if you are smelling it when it is overheating it could be the steam releasing through the over flow container.

[mcaramb]

Another overheating problem here. Mine goes redline waiting in traffic though, not during long trips. I suspected the fan clutch or the themostat from the get go, but mostly because I was putting too much faith in the idiot of a mechanic I was using, I didn't decided to change either until today.

Over the past 3 months I've replaced two radiators (one blew out at the top), every single hose has blown and needed replacing (including the one cooling the throttle housing), the radiator cap, and even the water pump which had started leaking!

I kept telling the guy that too much pressure was building in the system which was causing the problem, and could it be the fan clutch or a sticking thermostat. He kept saying naw, your car's just old and you've got lots of leaks everywhere... so we've been chasing monkeys for months now.

So, I'm changing the goddamn fan clutch myself now that it just went thermonuclear again in the parking lot. Half the water was missing out of the radiator, with no puddle this morning under my car or at work. I think it's all gone out as steam through some tight leak somewhere, or maybe the overfill tank valve.

What I'm curious about is how to tell if the fan clutch is actually bad. It spins at idle, but I don't know if it's at the right speed. With the engine off, it spins very freely by hand. Is it supposed to do that?

Thanks
Mike

[IRONVIKING]

I went down to Autozone and got and electric fan for 55$ and it took me 10 mins to put it in. Came with a thermostat that you stick in the radiator fins.
Ive only had one prob and that was because some brush had managed to push the thermostat half out so want getting good contact.
But its worked great, gives me more room in the engine compartment.
It may be easier to just dump the stock fan and go this route then you know the fan is for sure good. You could even hook up a switch to turn it on when ever you wanted.

[etlsport]

as triathlete said.. if there is 100% antifreeze in the radiator, that probably accounts for some of your problem.. antifreeze doesnt cool your engine that well, the water mixed in does most of the cooling.

a 50/50 mix of antifreeze (ethylene glycol) and water has the ability to absorb about 33% more heat than just straight antifreeze at 160ºF

antifreeze lowers the freezing temperature, raises the boiling temperature, and has additives to prevent corrosion of aluminum radiators

[IndianaVX]

im still fighting my battle with the overheating too. got a fan clutch from a 99 trooper, and put it on. blows all kinds of air now. i can see that my old one was probably bad by comparison. feels like ive lost some horsepower, it may just be me, i almost think it changed my shift points!?!

anyway, it was fine for about 2 weeks, and the overheating started again.
i am thinking pressure also. but i dont know where from.
at least now, i can go for a week or so, till it overheats. but i am low on coolant every time, and my firewall, beside the brake booster, it is covered with coolant every time it overheats, coming from the resivour.

[Y33TREKker]

Anyone ever tried replacing their radiator cap when experiencing these issues?
Radiator caps are supposed to both maintain adequate pressure and vent excess pressure, but they can go bad just like a thermostat, and a lot of these problems sound like excess pressure is building up in the cooling systems and forcing out coolant.

Our caps are rated to vent pressure from ~ 13-17 psi, but maybe Isuzu got a bad batch? I seriously hate throwing parts at a problem to find the solution, but in this case it would at least be an inexpensive potential fix.