New owner with heater problem

[explicit408]

Hello all,

I just drove my new '93 Rodeo home. Its nice and clean with 132K on the odometer. As I was driving it home in the rain I turned on the defroster and set the temp to hot but the air never got hot. The drive home was about 45 minutes and my temperature gauge never passed the halfway mark. There is no leaks and the coolant reservoir tank is about half way full. What could it be?

[trooperbc]

well, you do have a coolant circulation problem, and that could be a number of things.
first, don't go by the reservoir. undo the radiator cap, with a rag and smarts if it's hot, and check the coolant there. it's possible that the system is way low on fluid, and you are not getting enough circulation to the heater core, and/or you have an air bubble in there blocking things
how's the temp gauge?
do this first thing. you do not want to be driving your new baby around without enough coolant.
if the engine is hot/warm, add coolant with the engine running. add to full, goose the throttle some, run until you are sure the thermostat is open and refill as needed. put cap back on.

report back. there are a number of other possibilities, but that is the first step.

some other possibilities
clogged heater core
heater bypassed by previous owner/seller because heater core leaked
water pump defective
clogged radiator
and others (?)

hth

//bc

[explicit408]

Thanks for the reply!

Temp is good. Never went past the halfway mark on a 45 minute drive. I was about to remove the radiator cap but coolant started spilling out so I assumed there was enough in there. I just noticed a slushing sound when I take off coming from the glove box area. Could it be a clogged heater core?

Also, another thing I just noticed is that the temp selector wont slide all the way to cold. It will slide all the way to hot. Is that normal?

[Ramblin Fever]

Slushing sound could be one of two things; washer reserviour making noise if it's full of fluid. Or, an air bubble in the cooling system.

Just because it spilled out when you begin to open after it heated up, doesn't always mean it's full.

The hot/cold selector issue, no that's not normal.

Did the previous owner have any records of service/maintenance?

Sounds definitely like a cooling system issue, and If there's an air bubble depending where it's at, the temp gauge may not be telling the truth.

What I would do, is either perform a cooling system flush yourself, or take it into a shop & have it done ASAP - have them change the thermostat while they're doing it.

If that's the original radiator, could be blocked with age and may need to be replaced, they typically only last for a good 10-11yrs.

Just replaced mine on my '97 within the last few months, my engine had never gotten hot or over the half mark, but it now runs a tad cooler. Even after having performed flushes every-year, radiators can only last so long.

[explicit408]

Well the washer reservoir is empty so its not that.

Ill check the radiator level again.

What would cause the temp selector to do that? Could it be that it is off center and not really going all the way to hot when I select it? Because the air it does throw out is a tad warmer than outside air.

[Ramblin Fever]

Have no idea on the temp selector, I'm sorry. Unless something is jammed inside where the dash is.

Ok, if your washer reserviour is empty; then yes, sounds like an air pocket in the cooling system.

Park your truck on an upward slope - nose up and preferably starting with a cold engine, take your radiator cap off, if it's low, fill to the brim and then start the truck (with radiator cap off). Also make sure your overflow reservior is above the minimum line, and put it's cap back on.

Allow the truck to run to normal operating temp 15-20 minutes depending on how cold it is outside, rev the engine a bit nothing horrendous, if the level in the radiator goes down via bubbles popping out, add more coolant to bring it back to the top - keep doing this for at least 20 minutes or until your satisfied that all the bubbles have stopped.

Put radiator cap back on; allow the engine to completely cool down, i.e. 3hrs or so, and double check level in coolant reservior tank.

I generally keep my reserve tank in the middle of high/low marks on a cold engine; when my engine's at normal operating temp, my coolant reserve tank is right at the high mark.

Still think you need to have a coolant flush done; any known history on this truck?

[surferfletch]

The first thing that came to my mind was the previous owner bypassing the heater core because of a leak. Look in the engine bay near the fire wall on the passenger side to see if the heater core hoses are intact and properly routed. If you did have some coolant in the HVAC box sloshing around, I'd think you'd notice the sweet smell of coolant, though.

[trooperbc]

Originally Posted by explicit408

Thanks for the reply!

Temp is good. Never went past the halfway mark on a 45 minute drive. I was about to remove the radiator cap but coolant started spilling out so I assumed there was enough in there. I just noticed a slushing sound when I take off coming from the glove box area. Could it be a clogged heater core?

Also, another thing I just noticed is that the temp selector wont slide all the way to cold. It will slide all the way to hot. Is that normal?

ok explicit, all this is making me think it's the heater core [third step on the list] and the previous owner tried working on it (hence the temp selector screwed up) and gave up and just bypassed it (hence the no heat and the sloshing sound of the partly-filled heater core). i'm currently negotiating with myself about replacing my heater core or first just trying to replace the heater hoses.

here's a photo of the heater hoses in the engine compartment of my 1992 trooper v6 3.2L. yours should be the same or similar. if the heater core was bypassed, the two hoses would be disconnected at the top of the engine and a single hose would connect the two 'pipes'.



replacing the hoses is tough (at least on my 92 trooper), and replacing the heater core, from my research, is a real PITA, so it wouldn't suprise that the previous owner would give up on doing the work (not to mention the $300 or so for the new box with core).

what i'd do:
***visually check for heater core bypass
***then check the coolant stuff, even if the heater is bypassed; you want to make sure this guy didn't shortcut something else.
***then get to figuring about the temp selector if everything else checks ok. there's no sense doing anything with that if the heater box has to come out because you will just do it all over again [besides, it's probably just an adjustment of the wire]

btw, these heaters don't have a heater valve -- coolant is always going thru the heater core (when it's connected). the temp switch just adjusts a swinging gate door to allow air to cross over the heater core for heat, more and less.


hth
let us know what you find


//bc

[explicit408]

Thanks for all the help guys.

The heater hoses look exactly like that. They go into the firewall and they get hot.

This morning I put some coolant in the overflow and started the car. I took the cap off the radiator to check for bubbles. Let it idle for 10-15 minutes and when the thermostat opened up I started reving and at first a few big bubbles came out but then it started foaming. The level never got low enough to see the core. And still no hot air.

A friend told me it has to be a clogged heater core. Since the car doesn't overheat and its not leaking coolant into the cabin.

The coolant looks pretty fresh so maybe they didn't bleed the system right. I also have a feeling the temp switch isn't pushing the gate all the way to allow the hot air through.

Damn, I think I'm just going to have to take the dash apart and inspect the heater core and temp switch.

Know where I could get a cheap shop manual?

[trooperbc]

Originally Posted by explicit408

The heater hoses look exactly like that. They go into the firewall and they get hot.

well, that's a good start anyway.

but then it started foaming.

but that doesn't sound good at all. foaming would indicate air. so maybe it it isn't fully bled and you do have an air bubble in there blocking circulation thru the heater core. [[[i''ll hesitate saying anything about a possible head gasket until you say there are other indications that that might be the case ]]]]

A friend told me it has to be a clogged heater core.

certainly could be. but it's such a pita to get to the core, i'd want to rule out all other easier possibilities first myself....especially with the air indicated by the foaming you mentioned.

I also have a feeling the temp switch isn't pushing the gate all the way to allow the hot air through.

that also sounds plausible.

Damn, I think I'm just going to have to take the dash apart and inspect the heater core and temp switch.

you might want to follow the wire from the 'switch' to the heater box to see if you can tell it's not hooked up correctly. it's also possible the guy replaced just the heater core (not the whole box the way isuzu wants you to now) and he messed up one or more of those trap doors. any other ventilation problems?

Know where I could get a cheap shop manual?

no
but here's the site for the expensive one
www.helminc.com

good luck
//bc

[HI JOHN]

I had a similar problem were my rodeo was not getting warm at all. It turn out that the thermostat needed to be replaced. Now I have no problem and the car warms up with in 10min.
PS. If the engine is not warm enough, it will only blow regualar air.
Good luck and please let us know what was the problem.

[surferfletch]

Yeah. Maybe the tstat is just stuck open.... I think you'd overheat if there was a clog or air in the system.

[Ramblin Fever]

What I would do - get your system flushed along with a new thermostat; then go from there on any repairs that might be needed.

Foaming is not a good thing - BUT, good thing is, is your truck is not overheating, which is good on an all aluminum engine. Could just be a lot of air in the system, a bad radiator & a bad thermostat.

Changing the thermostat on the earlier models is no biggy, just make sure to get an OEM one.

BTW - I wouldn't keep driving it - you're probably not anyway though.

[explicit408]

What would explain the slushing sound if the t-stat was stuck open?

Besides, yesterday when I took the radiator cap off and started it, there was no flow until about 10-15 minutes of idling.

[IJAPA]

My New 99 Honda Passport From An Open Auction Came Today Without A Remote ,it Turns But Would Not Run The Security Light On Dash Wiith Key Sign Keeps Flashing Red, Battery Very Dead
I'm Waiting For New Remote What Should I Do Next
Regards
Ijapa