Over heating issue

"DC3 LS, Fuck Hyundai, now and forever" (eg6)
07/10/2019 at 12:50 • Filed to: None

Pic unrelated

So it does fine when parked/ idling (even cools down if it’s hot). But starts to overheat over 40 mph. Under that it’ll be fine with the heat on as well.

Unfortunately, I think this means it’s not the thermostat, although I could be wrong. Since I don’t think it would cool down at all with the thermostat stuck.

Waiting for it to cool down before checking coolant level (overflow tank is too dirty to check) but there’s no obvious leaks, so I’m expecting the coolant level to be fine.

Also oil color is fine and no white smoke coming out tailpipe. Water pump was replaced before I got it.

Does this mean if the coolant level is fine, I need a new radiator?

DISCUSSION (18)

CalzoneGolem > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 12:58

Open the overflow and shine a flashlight into the hole to check the level.

Boxer_4 > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:05

Sorry if I missed it, but what car is this?

Discerning > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:06

Look around your water pump. Do you see any leaks or weeping?

Taking taking the car up to 40 or faster and come to a stop and check again. Anything then?

Check around check around the hoses at the necks of the radiator.

I had a jeep run warm that had a water pump going bad. No smells, no coolant on the ground, and coolant went down slowly over time. But the big 5.9 not getting an optimal flow at speed resulted in similar to what you are describing. Pulling over brought the temp down but highway resulted in increased temps.

Al so check the fans and radiator for debris

HammerheadFistpunch > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:07

sounds like the rad. If its cool at low speeds but gets hot at speed its likely a flow issue. either too little airflow or too little coolant. You could flush the radiator fins with high pressure water from behind to clear out any potential blockage and you could run a flush through the core to clean out the internals.

DC3 LS, Fuck Hyundai, now and forever > CalzoneGolem
07/10/2019 at 13:11

The overflow is stupid and doesn't have a cap.

DC3 LS, Fuck Hyundai, now and forever > Boxer_4
07/10/2019 at 13:11

2001 Hyundai Accent.

DC3 LS, Fuck Hyundai, now and forever > Discerning
07/10/2019 at 13:12

I didn't take a close look at the pump. But nothing was leaking out of the lower timing cover, which has happened everytime I've had a water pump leak.

DC3 LS, Fuck Hyundai, now and forever > Discerning
07/10/2019 at 13:14

Oh yeah, it'll cool down if I stop after its overheating. Even at a red light.

RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:14

I’d still check the thermostat.

CalzoneGolem > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:16

What? That doesn’t make any sense.

DC3 LS, Fuck Hyundai, now and forever > CalzoneGolem
07/10/2019 at 13:29

Idk. It just has two little lines and no cap.

HammerheadFistpunch > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 13:30

it should look like this, no?

Kinja'd!!!

the cap is where the line comes in.

DC3 LS, Fuck Hyundai, now and forever > HammerheadFistpunch
07/10/2019 at 13:52

Have to double check. But I don't think so. Omw to work so it'll be later or probably tomorrow.

Aremmes > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 14:01

You say it’s OK at low speeds with the heat on. Does it still overheat at low speeds if you turn the heat off? If so it's possible that your heater core bypasses the thermostat, thus providing some cooling capacity even when the thermostat is stuck shut.

Discerning > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 14:06

I would check all over for even the tiniest amount of weeping. Maybe get some UV dye and see if you spot the dye a nywhere after a hot run.

Fuckkinja > DC3 LS, Fuck Hyundai, now and forever
07/10/2019 at 16:42

I worked on a co worker’s mini van that was doing the same thing. After replacing the radiator it still was happening. I pulled the not leaking water pump and the impeller was completely gone. It d efinitely had some rusty coolant though.

DC3 LS, Fuck Hyundai, now and forever > Aremmes
07/10/2019 at 23:03

It’d overheat just a little bit around town with the heat off, especially up hill or accelerating , but with it on it’d stay in the happy zone.

DC3 LS, Fuck Hyundai, now and forever > Fuckkinja
07/10/2019 at 23:05

interesting, I would’ve thought if the water pump was gone it’d just overheat all the time. Might just take it into a shop since I don’t wanna wast my little free time diagnosing this.