Hello, my car started to overheat recently. I have inpa and it said that my resistor was broken. I don’t really know how to strip a wire and rewire it so I replaced the whole fan. Filled up with coolant. Lifted the front bleed it and I saw the fan turn on now. But I still overheat. And it’s related to the fan because whenever I start to overheat I drive and the temp goes down. Could it been even more bubbles in my system? Or did I leave something? I’m very lost

 

Has your thermostat been replaced? That could be your culprit.

 

but I don’t understand the temp only goes down when the car is moving and air gets blown into the engine. How can it be the thermostat? Does the thermostat just stay closed?

 

You answered your own question. It's the cooling effect of air across the radiator that decreases the temperature. And, yes, it's possible that the thermostat is either stuck closed or fails to open completely. It's a cheap fix (if you do it yourself) and the first thing you should do.

 

The low-speed fan resistor failing should not cause the engine to overheat. That's because even when the low-speed fan resistor fails, the high-speed fan will still work and prevent overheating (unless you do something dumb like rev your engine too much while sitting there).

It's likely your problem is that coolant isn't circulating properly. Could be the thermostat like @cooper48 said, it could be the radiator that's a bit clogged, or the system not bled properly. For that last one, did you bleed it properly? If you have a r50, there are 3 bleed screws, and you must fill the thermostat when bleeding, not the coolant expansion tank.

Plugging an obd2 scanner and checking live coolant temperature might give more clues. Or you can replace parts at random until it stops overheating.

Edit : did you change the coolant too? If your low-speed fan resistor has been broken for a while, it's likely a bit of the water boiled in the coolant expansion tank, meaning you don't have a 50/50 mix of coolant/water, and glycol doesn't transfer heat as well as water. Though from first hand experience, I wouldn't say it's likely to cause overheating.

 

I walked to my car when cold and checked my coolant level and it was dry in my tank. When doing the fan replacement I topped it off with coolant. And I was thinking, could it be possible the type of coolant I put in the car? I used a ShopRite branded coolant. I went ahead and purchased the 20 dollar coolant gallon from AutoZone for German cars (blue). I feel as if the ShopRite coolant just burned up literally.

Also, before replacing my fan I would hear it turn on and its really loud. After replacing it, I still hear it! I don't know why.

Could the loss of coolant be because of the coolant type? Or do you still lean towards the thermostat failing?
TIA

 

> I walked to my car when cold and checked my coolant level and it was dry in my tank.
Forget about bleeding or defective parts, a car that doesn't have enough coolant will overheat.

> When doing the fan replacement I topped it off with coolant.
Is it a r50 or a r53? If it's a r50, topping the coolant expansion tank isn't going to cut it if it was run dry (or if you change the coolant). You need to properly bleed it and fill it via the thermostat cap. Not sure for a r53, but it's probably the same.

> And I was thinking, could it be possible the type of coolant I put in the car?
No. Unless you are putting plain water in it, all commonly accessible coolants will be able to run at the engine operating temperature without issue.
Though you have to take care of not buying a coolant that can damage your car, because there are aluminium parts and some coolants are not meant to be in contact with aluminium parts and will destroy those.
I can't help you with those coolants brands unfortunately.

> Also, before replacing my fan I would hear it turn on and its really loud. After replacing it, I still hear it! I don't know why.
Low-speed fan will turn on at about 105°C coolant temperature, then high-speed fan at about 112°C coolant temperature. This is normal to happen when sitting in a jam.

> Could the loss of coolant be because of the coolant type? Or do you still lean towards the thermostat failing?
No, loss of coolant is not because of coolant type.
I'm not leaning on anything because you provided very little information to go on.

You should consider bringing the car to a mechanic honestly. Otherwise, you got a whole lot of learning to do to properly diagnose the situation. Considering you might have run the car without coolant and overheated, I'm also concerned your head gasket might have started to go (or maybe that's where the coolant went).

 

Suspect you still have a ways to go to get the air out of the car's cooling system. You haven't mentioned whether this is an R53 but guessing it is if you've gone to the trouble and expense of scoring a copy of INPA. If it's an R50, ignore everything I wrote after this.

There are two bleeds - the one you see in front of the intercooler when you open the hood and the second one down below it on the transmission bell housing side of the engine (technically, behind the block, with respect to the crankshaft axis). There's a water pipe down there with an almost invisible bleed screw that you need a flashlight and long extension to clear before moving upstairs to the other one. Don't back the screw out too far or you'll lose it and never find it again, or the bleed port.

The other thing as one person mentioned is thermostat, which in fact could be failed, improperly installed, or both. It has a tiny little airbleed hole in it near the outer edge that is supposed to be installed with the hole in the upper most 12 O'clock position. If it's installed in any other position than 12 you'll never get all the air out of the block.

Finally it's imperative to make sure the heater is on HI with the fan speed at the lowest (one) setting to properly burp the core.

Good treatise on proper bleeding and other helpful tricks over at Pelican Parts DIY tech section:
https://www.pelicanparts.com/techart...eplacement.htm