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Heat gauge shooting up when using AC?


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JudeGreyH
New User

Jun 28, 2014, 4:59 PM

Post #1 of 11 (1299 views)
Heat gauge shooting up when using AC? Sign In

Hello:

I hope this is in the right spot!

I just purchased a 98 Kia sportage 4x4 last week. It has approximately 95k miles on the engine (2.0), had a new exhaust system installed, a new oil cooler installed (apparently, it has a tow package, and there was a massive oil leak from the bottom of it), and a variety of other parts repaired or replaced before purchase. Before I got it, it had been sitting for a while not being used... a couple of months at least. When the mechanic had it, they had apparently checked all the fluid levels and pronounced them fine.

Today was my first day ever taking the thing out onto the highway. I have driven it around the city for the past couple of days, though. It seemed to do great... The heat gauge remained just below the middle tick and stayed there, even after running the engine at around 65 miles an hour for about 40 minutes. The engine issurprisingly quiet... no knocks, pings, or rattles. However, when I turned the AC on at a red light, the heat gauge immediately started creeping up... and fast. I pulled over, stopped the car, and checked to make sure it wasn't overheating, but it didn't seem to be. As soon as I turned the AC off, the gauge went right back down to where it had been all morning. The AC is pumping cold air, though seems sort of weeny, power-wise, but as I just got this car, I am not sure how powerful the AC is supposed to be.

The dude had replaced the dashboard and door panels before I got it, and I am having some other issues with shorts here and there, namely the windows and door locks, with occasional buzzing on the driver's side door stereo speaker. Everything on the dash is working (Radio, clock, signals, lights, etc). It doesn't seem to be a thermostat issue, and I am hearing the fan kick on, though honestly I wasn't paying super a lot of attention when I was trying to figure out what was going on with the heat gauge. Initial research suggests that this might be due to an airbubble in the coolant system, possibly? Or a fan short? Essentially, I am a newbie in terms of self-repair, but just dumped a lot of cash into this sucker to get it driveable. It seems to do perfectly fine when the AC isn't on, and there doesn't seem to be any leakages underneath. Should I try to burp the radiator? Or replace the fan? There was also the suggestion that it might be due to a bad battery? Any thoughts?


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 28, 2014, 6:27 PM

Post #2 of 11 (1283 views)
Re: Heat gauge shooting up when using AC? Sign In

Too late now but should have passed up that car and any should have been checked out prior to purchase. IMO the up front issue is overheating needs correcting. Either fan(s) aren't working properly or radiator or other things are not capable of the extra heat load of using A/C.


Whatever it takes you must tend to potential serious overheating or IMO it's game over for this car. Cheap car when new, now old in need of lots some not just usual age and use but screwed up it sure seems.


? Is it really overheating or just normally running warmer with A/C which could be normal. If that's not normal heat is an engine killer and this would exceed if it failed being a disaster for this car,


T



Hammer Time
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Jun 29, 2014, 12:25 AM

Post #3 of 11 (1267 views)
Re: Heat gauge shooting up when using AC? Sign In

Exactly how much hotter did it get? Did it go all the way to the red zone?

Did the fans come on and stay on when the AC was turned on?

Was the air cold at idle?



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



JudeGreyH
New User

Jun 29, 2014, 12:38 AM

Post #4 of 11 (1260 views)
Re: Heat gauge shooting up when using AC? Sign In

Boy, I hope this isn't a seriously bad issue, Tom Greenleaf! I am hoping I just have a short somewhere!

Hammer Time-

I didn't let it get super high before I turned it off. I general, the truck has been maintaining the heat gauge at a little below the middle tick for the entire time it has been running, no fluctuation. When I ran the AC for a couple of minutes, it started shooting right up. I let it get to the second tick above the middle line before I shut the AC off and pulled over to check the radiator. When I turned it off, the needle dropped right back down to where it had been all morning... just slightly before the middle tick. The radiator wasn't boiling or spitting and the engine sounded fine. (I am well acquainted with overheated radiators... my old truck overheated if you looked at it funny.) I didn't want to let it get up too high before turning the ac off, as I didn't want to blow anything.

As a note, before I bought this thing, I had it checked over by a certified mechanic and it passed state inspection, if that helps rule out any big things. Essentially, I needed something to drive in a hurry... this little Kia was reasonably priced and in decent shape.

As for the fans... I am not 100% sure if they kicked on for the entire time. I know they do seem to be running, but I am planning on checking that out this morning. The AC does run and blow cold air at idle, though, as I mentioned previously, it doesn't seem to have a lot of power behind it. I am not terrible confident in the guy I bought it from's ability to install a dashboard, though.

Also this didn't seem to be a problem before I got my oil cooler replaced a few days ago. They also replaced both battery terminals at the same time.


Hammer Time
Ultimate Carjunky / Moderator
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Jun 29, 2014, 12:42 AM

Post #5 of 11 (1256 views)
Re: Heat gauge shooting up when using AC? Sign In

You may have no problem at all. We need to find out just how hot it will get because it is normal for the AC to cause it to run a little hotter, especially in slower traffic. I would leave it on to see what it does. As long as it doesn't go into the red area of the gauge, you are safe.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



JudeGreyH
New User

Jun 29, 2014, 12:45 AM

Post #6 of 11 (1252 views)
Re: Heat gauge shooting up when using AC? Sign In

Ok! I will try that today and report back!

It could be that I am just super paranoid... I have been having nothing but bad luck with cars, and I drive a lot for my job, so I really need this thing to keep rolling!

I am still planning on checking the coolant levels this morning, just in case I do have an air bubble somewhere in the system, and was planning on having my battery tested anyway, as it looks a bit old.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 29, 2014, 1:22 AM

Post #7 of 11 (1246 views)
Re: Heat gauge shooting up when using AC? Sign In

Sorry if I did seem bit worried about this vehicle right out of the gate had some issues that I would have rejected this one but that's history so let's get this heat/overheat understood.


Hammer Time just said and agree it could be normal but not if spiking into "red" zone on the gauge. You mentioned that the battery could be causing this by someone's suggestion and NO that isn't the up front issue so stop listening to that but sure have it cleaned and tested so you know it's good or not. Once running it's mostly going along for the ride if charging system is fine and must be as you would be having no start issues already.


I do worry about a dash being all apart and poorly put back in place properly.


About a bubble in cooling system: Probably not by now if you are checking level and now stable for the temp chances are it has purged out any air (if any) was in it from opening it up for any reason. True low coolant or air generally shows right up as a problem A/C or not.


Don't guess but know fans are operating correctly for low speed operation and use of A/C -- many vehicles fans will come on full power with A/C request at any temp - some wait and don't know which each model of what does what but none made to really overheat over it.


Note that A/C is making heat while providing cool so a strain on a cooling system if marginal it would show up more when in use,


T



JudeGreyH
New User

Jun 29, 2014, 1:28 AM

Post #8 of 11 (1243 views)
Re: Heat gauge shooting up when using AC? Sign In

Thanks for all of your suggestions! This is not a problem I have dealt with before, so I am a little lost, and just going from what I have found out in internet research over the problem.

If it is a fan, I think I can probably replace it on my own. I'll check on whether or not it's kicking on for the full time wiith the AC running.

I will report back with my findings!


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 29, 2014, 1:33 AM

Post #9 of 11 (1236 views)
Re: Heat gauge shooting up when using AC? Sign In

In short - pay attention to it. I could be a two speed fan, one fan or two fans and not sure what would be used depending on what it came with new. IDK if HD cooling was an option that would change the way it should be working. Nothing beats being there vs the web at it's best isn't competing with hands on observations. Again - it's high on the list of things to pay strict attention to, that all,


T



Discretesignals
Ultimate Carjunky / Moderator
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Jun 29, 2014, 4:24 AM

Post #10 of 11 (1225 views)
Re: Heat gauge shooting up when using AC? Sign In


Quote
a new oil cooler installed (apparently, it has a tow package, and there was a massive oil leak from the bottom of it)


Engine oil cooler or transmission oil cooler? If it has a cooler in front of the condenser, did they clean the condenser and radiator fins out? Sometime you get oil on the fins and they become plugged with dirt and road debris.

Also the Sportage has an engine driven fan. The electrical fan is used for the condenser. Probably would be a good idea to check the operation of the fan clutch and make sure the shroud is intact. If original, the 16 year old fan clutch is probably worn out.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Jun 29, 2014, 4:25 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 29, 2014, 4:51 AM

Post #11 of 11 (1216 views)
Re: Heat gauge shooting up when using AC? Sign In

Good thought and ideas DS no surprise coming from you. I didn't know this uses a fan clutch and they plain are NOT real good after a few years never mind if original. Does seem HD stuff everywhere with tow package, oil cooler and so on.


Fan for condenser (one up front of everything no doubt) may be poor, inoperative or if replaced some end up spinning the wrong way - easy to check for that and would cause some wild problems getting air thru but doesn't explain why A/C still blow cool enough?


Some checking to do as already said, Tom






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