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Discussion Starter · #1 ·
My problem is this..amoungst all my other problem posts lol

When I stop the truck after driving a bit, I can hear the coolant resivoir boiling. The truck shows it never gets hot and the a/c still works fine and it runs and drives fine. But the heater doesnt blow hot air. I replaced the thermostat and added coolant to the resivoir and topped off the radiator and replaced the cap. When I start the truck and it gets to operating temp, the thermostat to raidiator hose is really stiff and not too hot. The hose going to the block and radiator is really hot. If I loosen the radiator cap, it shoots boiling water everywhere and shoots it out of the resivior also.

I have read that my truck may have a bleeder screw for the coolant on the thermostat housing, but I have no idea what it looks like if it has one. All I can see is three screws that hold the thermostat housing on. How can I bleed my coolant system and stop the boiling over issue and make the heater blow hot air again?
 

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Have never seen an oem tstat housing for 3.2 motor with a bleeder screw. Sounds like you have air in the cooling system.

With engine cool - remove rad. cap and add any missing coolant. Start eng. let it warm up -then blip throttle 3 or 4 times. I put an old sock over the rad neck to keep it from getting all over things. This forces out trapped air. You should now have heat coming out of heater. Top up coolant - install rad. cap.

In extreme cases of air-lock - it helps to elevate the front of vehicle while you are doing this.
 

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Discussion Starter · #4 ·
Well, I called a few auto parts places as well as radiator shops....all told me the old "radiator cap off while running" technique. that didnt seem to work well for me, spewing antifreeze everywhere and still having air in the system. One place did tell me a way....when its cold, fill radiator to the top and resivior where it should be, let it run to operating temp then shut it off and let it cool again, fill radiator again and start and run to operating temp....do this over n over til you cant add water to radiator anymore when its cold. then its bled. That is what i was told via a radiator shop near me. I have been doing this for about 4 hours now and can still see air bubbles coming up in the resivior and both radiator hoses are tight as hell....is that way working, dont know but its all i got to go on at the moment. Heater is starting to blow warmer air though.

If I turn the radiator cap to the half way point (not totally removing) it will boil over into the resivior and spew out all over the place....still need more advise :/
 

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Squeezing the hoses sometimes helps get the air out.
 

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Discussion Starter · #6 ·
Update....

I did what both isuzu95, catfuzz and local radiator shop told me (which is all about the same)....no avail. It is doing the exact same thing, bubbling and boiling when I stop from a 15+ minute trip from the resivoir. After it cools, about half a gallon needs to be added to the radiator each time. It is pushing the antifreeze out from the resivior each time at about half a gallon at a time and spraying it all over the inside of the engine compartment.

So, I still need help....something obviously isnt right. New parts include....thermostat, fan clutch (non elect fan) and radiator flush. No leaks.
 

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this might sound stupid but it works on the 2.6L. park on an incline. ramps work too, just leave it running. did you use an OEM thermostat? also take the top hose and thermostat housing off and fill the coolant through there, while on the ramps/incline. once its full, put it back together. run the engine with the HEAT on all the way and FAN on high. sounds like an air pocket at the back of the motor where the temp sensor is at. try a new radiator cap too...a faulty cap will not allow the correct pressure needed in the system.
 

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Are you sure the thermostat is opening?

I've always bled my system this way, i.e radiator cap off allowing air to escape then put cap on after topping it off.

If you take the cap off after engine has been running, it will spit antifreeze everywhere cause it's been under pressure....don't think that's what you're asking though.

That said, how old is your radiator? If it's original, get it out asap, that could be the problem....even with regular antifreeze maintenance intervals, these radiators are only good for 7-9yrs or so before they get internally blocked up.
 

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o really my radiator is orginal and has 155 k on it ! never any probs. perhaps it has to do with my yearly faithful cooling system maint.
 

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olzuzurodeo said:
o really my radiator is orginal and has 155 k on it ! never any probs. perhaps it has to do with my yearly faithful cooling system maint.
I did mine yearly as well, I didn't have an actual problem - yet - with mine at the time I changed mine out, which was around 190k miles or so. However I definitely wasn't going to wait till I had a problem, been there, done that and ruined a perfectly good engine on another vehicle solely because the radiator was left in too long.

I have an automatic transmission in my rodeo, so keeping it extra cool along with the engine is utmost important to me, I can't afford for the engine or tranny to ever overheat, and we can easily see 11,000ft mountain passes here in Colorado....areas most vehicles never endure, which require a very good, clean cooling system or your toast.

I have 2 rodeo's, bought both new, the 91 has 350k miles, the 97 has 200k - both of these trucks are maintained better then I eat :lol:
 

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Discussion Starter · #12 ·
olzuzurodeo said:
o really my radiator is orginal and has 155 k on it ! never any probs. perhaps it has to do with my yearly faithful cooling system maint.
mine has 210k miles, i just bought it a few months ago....it has had alot of work done to it under the hood, just not the cooling system.
 

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Discussion Starter · #13 ·
Well, another update....

I took the truck out today for about a 20 min drive and it totally overheated. I was at a gas station and let it cool down and refilled it with water. The truck would barely crank and as it did the pressure was so great that it would blow the top off the resivior and spew the coolant/water everywhere. If I take the cap off the radiator and attempt to start it/crank it, it will spew a 2 foot high stream of coolant from the radiator. If I put the cap back on, it just builds pressure so great just after a few cranks that both hoses from the radiator are hella tight. I removed the thermostat thinking it was stuck closed, but that wasnt the problem and it did nothing.

The truck now will not start, it acts like it wants to but wont. The oil disptick still show the same amount of oil and doesnt show over full like water got into it. Why is my cooling system building so dang much pressure with just a few cranks and blowing all the antifreeze out thru the resivior? If I finally do get it started, it idles and drives fine but will only go a few miles before all the coolant has blown out either thru the cap or the resivior.

Why again so much pressure building up and why dont it want to start and run now? :(
 

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If it has that much pressure, makes you wonder if the block is cracked. Wish I could tell you not to drive it, but it's probably your only truck.

If that cooling system was neglected prior to your purchasing it, chances are it may very well have led to headgasket or block issues.

Your oil level doesn't always show an increase when the block cracks; these are all aluminum engines, they will crack if allowed to overheat sometimes once is all it takes.

The fact that it won't restart is also a sign of something extreme; however, could also be the waterpump failed and snapped the timing belt.

Same thing I just mentioned on another cooling system issue thread, take your truck to a mechanic, have them run a coolant system presure test, around $50 or so, they can tell you what the exact problem is. Better then playing guessing games, and it could save your engine.
 

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Discussion Starter · #15 ·
Ramblin Fever said:
If it has that much pressure, makes you wonder if the block is cracked. Wish I could tell you not to drive it, but it's probably your only truck.

If that cooling system was neglected prior to your purchasing it, chances are it may very well have led to headgasket or block issues.

Your oil level doesn't always show an increase when the block cracks; these are all aluminum engines, they will crack if allowed to overheat sometimes once is all it takes.

The fact that it won't restart is also a sign of something extreme; however, could also be the waterpump failed and snapped the timing belt.

Same thing I just mentioned on another cooling system issue thread, take your truck to a mechanic, have them run a coolant system presure test, around $50 or so, they can tell you what the exact problem is. Better then playing guessing games, and it could save your engine.
Well, I looked and the timing belt is still in tact and there is no oil in the coolant (if that means anything)...right now the battery is dead from trying to start it yesterday. The only two turn-overs it let me do before battery giving up and the pressure had built up enough to have a second or two of air pressure release when I turned the radiator cap. Whatever is causing this high pressure in my coolant system will not allow me to drive it to a mechanic, at best I could get it started and get it a few feet into my garage so it isnt an eye sore having me under the hood for all to see lol.
 

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Discussion Starter · #17 ·
isuzu95 said:
short on time - so i haven't read entire thread - have you pulled a plug or 2 on each bank - wonderin' if they're - wet.....coolant wet.
I havent yet....im short on time at the moment also, will probably look more into everyones suggestions this weekend.
 

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Discussion Starter · #18 ·
Well today I got it started, fired right up....I only let it run for less than a minute while moving it into my garage. I checked the oil and seen it was an off white color, guess water is mixing with the oil. What are my options now? Head gasket blown or cracked block?
 

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Are you the original owner of this truck?

curious as to why the gauge never showed hot....that's frustrating I'm sure.

honestly would venture to say headgasket issue, these 3.2L's from 93-97 are NOT common for having headgasket or cracked block issues, sounds like this truck was possibly not driven much in it's earlier days.
 

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Discussion Starter · #20 ·
Ramblin Fever said:
Are you the original owner of this truck?

curious as to why the gauge never showed hot....that's frustrating I'm sure.

honestly would venture to say headgasket issue, these 3.2L's from 93-97 are NOT common for having headgasket or cracked block issues, sounds like this truck was possibly not driven much in it's earlier days.
I am not the original owner, actually just bought it a few months ago. The gauge only showed a little above half way at its "hottest" point. The previous owner did some work under the hood like timing belt, alternator and said something about having the valves redone (not sure exactly what he did or meant). How can a DIY tell if the head gasket is bad or if the head got warped? Any kind of bs that can possibly be ran thru the radiator to seal a cracked block or head gasket?
 
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