majik

Alright.. my engine is still overheating. I was gone all weekend at NOPI Southeast in Bristol, TN/VA (took home 1st place).

Driving around the city of Bristol, stopped at traffic lights, my car started to overheat again. Happened twice this weekend. I flushed my radiator last Thursday, changed spark plugs, changed thermostat, oil, used STP fuel injector cleaner, STP gas treatment, and another bottle of "more concentrated" STP fuel injector cleaner (within about 2 weeks time and 10 fill ups, not all at once).

I'm going to drain and fill my ATF this week, and take my car to Hyundai dealership. I have 98,000 miles so they'd better fix it before it runs out of warranty... but WHAT could be causing this? My fans are both working (a/c and radiator fans).

Does anyone have ANY ideas!??! I know the dealership will just call Hyundai help line and ask them, and they won't get anything fixed, so I'm coming to you guys for help sad.gif

Mad_john

check the water pump also remove the oil cap and if you got brown cream you got a blowen head gasket, check your fan switch also and if everything is ok your gage is lieing to you but i am sure u will got more input from the guys here

did i miss anything i am in a rush so i mught have not listed every thing wink1.gif

hamhead

Yeah, the water pump is basically the only thing left that I know of...

Ya never know, maybe the temperature sensor is messed up, or the controls in the actual gauge are off... highly doubt it though, but ya never know.

Zman

I have up to four theories...

1) Water pump: check for strage noises with car cold right after you started, and also when operating temp; both at idle (if you can get under the car to hear better) and also slightly rev it up. Another way to check it would be to open the radiator and check if water is really moving at idle and let someone rev it a little more and see if you get a water current there.

If you have colant/water loose, even not a bigone, 2 and 3 apply
2) Radiator Cap: Beleive it or not, this tiny thing can cause a lot of trouble, it lets the vapors squeeze out bit by bit until it's enough to let an air pocket in your coolant system, if it's not new, change that first to discard it. You can check also by getting a medium drive aroudn town, before it gets too hot, let it cool and check if you lost coolant.

3) Pressure leak: This could be the most difficult to detect:
I have seen in other cars a tiny (almost microscopic actually) imperfection on the head, that lets high pressure vapors get out and has the same effect as the radiator cap, the olnly way to detect it is to let the engine warm up with the hood up and wait until it heats up (not overheat of course) and look carefully for little vapor clouds...

The other thing would be:
4) Thermostat, but I think you already changed it right?

Mad-Machine

car overheats when moving or when idling? Also, besides the obvious, what work did you do to the car before you started having the overheating problems?

majik

I had a blown radiator fan. I replaced the fan (it IS pulling air OUT of the radiator and into the bay). Couple weeks later it started to overheat (weather got hotter). That's the only thing.

I changed fluid and t-stat. I'm not losing coolant.

It happened when I was idle, or sitting at a red light. I drove 600+ miles on the interstate this weekend, and it didn't overheat once. If I'm sitting still is when it happens, then as I start to drive it cools down. I got off the interstate after 100 miles to get gas, and coming to a red light on the off ramp, and pulling immediately into a gas station, it started to overheat bad.

As long as I'm moving, it seems fine. sad.gif

Zman

Well, your problem is air flow through the radiator, typical of fan failure, but if it's not failing then maybe you didn't get the right fan? Maybe it's not enough for our cars, it doesn'¿t move enough cubic feet of air; or maybe they are defective and only rev half or less speed than they shoud be... thus not pulling enough air through the rad...
Are you sure your radiator front part is clean? Without any sign of laquer, paint, excessive dirt (I highly doubt it because you are into shows a lot) but if it had any kind of layer of any type it could influence also...

You haven't changed pulleys right? (so you are sure your water belt is not slipping?

IDK man, yours is a very rare problem, but I'd bet the problems is either on the fans itself, OR in the electrical wiring that takes power to them, maybe you have a cracked cable and it shorts in some cases, or you have electrical leaks and fans blow not at full power.

majik

I bought my fan from JonGTR on here. I'm assuming it's the right fan.

How do I check my water pump? When the weather is cool or damp, my belts squeel for a few seconds, but only for a few seconds, and they don't do it very often. It started after the dealership replaced Timing belt and all other belts (30,000 miles ago, when they replaced the transmission).

How do I check the water pump?

Zman

If you take the rad cap off, you can actually see the water moving inside the radiator, ask someone to rev your engine and you should see it moving more... of course it has to be done at operating temp, because when engine cold t-stat remains closed so you don't see anything in the rad.

But honbestly, I don't think your problem is there (check it anyways to discard it) if the car heats when it's stopped, IT HAS TO BE a lack of heat transfer from the water on the rad to the air, so, it is either:
1) Fan not working (maybe it works sometimes, sometimes not?)
2) Fan not blowing enough air
3) Radiator partially obstructed on the outside by paint or something like that, so it needs much more air than in normal operation to transfer heat
4) Clogged radiator (water passes only through part of it; if it's really badly rusted inside, not even a flush will declogg it) so only when a lot of water passes there and there is a lot of air going through (like highway driving) it cools the water

I don't know man, I'd check the electrical on the fans just to be sure.

One more.... when cold, touch your radiator hoses, they should be "hard" to the touch, if any of the hoses appears to be too soft, maybe it's worn out and when hot it's colapsing to the inside so restricting flow (when you are on highway water is much colder so it doesn't colapse that much... ) I've seen it happen... also check them cold AND hot.

4)

'treezy

Buy a bigger Hayden Radiator and THREE slim line fans (two behind radiator and oen in front where the OEM one is placed).

Then your engine will be OVER-cooled at the flip of a switch.