Hello again everyone. I've been having this problem with my FC overheating at idle. If im stuck in traffic, or just let the car warm up, it overheats. I blew a hole in one rad already, swapped it. I blew 2 hoses. I've changed the thermostat, and bought a new rad cap. I've drained and flushed the system, and am running 70/30, which I read on here was the best mix to go with. I've been told by people it could be anything from the radiator to the heater core. I'm just curious if anyone else had a similar problem. Weird little bit of information, I don't know if it is related, but whenever I accelerate between 2K and 3K rpms, there is a hissing noise coming from under the dash (heater core I guess). It stops after 3k. Anyone have a clue?? It overheated today, and I let it cool down and removed the thermostat. I don't know if it helped, because I hauled *** getting home, and it wasn't a far drive.

 

Are you running the stock fan? Overheating while sitting still or at low speeds could be caused by a bad fan clutch.

 

i am having the same exact problem bro, you are not alone.

 

+1 on fan clutch, or really loose belt maybe...

 

It sounds like you have a bad fan clutch

It sounds like you have too much pressure in the system. Did you get an OEM spec radiator cap? Did you get a new filler hose cap as well? There might be a clog in the system. Check the bottom hose off the radiator and see if it is hot, if only the top hose is hot, that means you have a clog in the system. If you have the money you should get a new radiator. You could go OEM, but if you have the money I would recommend KOYO.

Hissing noises are never good (except BOV's). Check for puddles of coolant under your car. Take off the plastic shield (I think thats what its called) under your engine to get a better look, sometimes that inhibits your ability to spot leaks. Im not sure but I think the heater core is actually behind the drivers side dash or around that area, but you shouldn't worry about that unless you have a strong coolant smell inside your car, wet floor mats, and a loss of coolant when your heater is on.

Removing the thermostat is not a good choice, your fc goes into limp mode and your fuel efficiency is greatly reduced.

Hope this helped

 

Yes, stock fan. Thats something I can take care of. I have a parts car I can swap the clutch out of and see if that helps.


@ 0verb00st : Thanks for the detailed response. I don't think that there is any leakage inside the car. I've never noticed any puddled fluid outside the car either (except for when I crossthreaded the brake fittings... but thats another story). Definitely no smell in the car. So scratch that idea, I suppose.

Also, I didn't know that about removing the thermostat. The only problem I anticipated would be taking forever to warm up the car on cold days. I will definitely put that back in. I'll also swap out the clutch. Thanks a lot guys!

 

Ok, um I swapped the fan clutch out from the donor car, and at first, it did lock the fan into place. Then after a few minutes of that it just freewheeled and never locked up again. Clouds of antifreeze consumed my engine bay shortly after that. While it was working the temperature dropped immediately though, so I'm guessing it was the culprit. However, this all happened with the thermostat out. I put it back in and retested, but with the same result. I have a line on one more clutch but after that I gotta go new ($180.00 oh god...). I don't know... Anything else to check? The clutch DOES work on heat right? It's supposed to bind up when it reaches a certain temperature range and spin with the water pump pulley right? Because all mines doing is freewheeling. I can stop it with my hand....

 

buy an efan?

 

Na, I barely have enough juice to run my HO headlights and heater at the same time. Besides i'm 80% sure I've fixed the problem. And because it is the most noobish thing I can think of, I'm embarassed to say how

 

Nevermind. It seemed ok. I ran it for 20 minutes and I didn't overheat, took it out for a few miles, and heated up again.

 

how old is your water pump?

 

+1 don't rule out water pump failure. BuT I agree on getting an e-fan.

 

Do not get an e-fan. Why? Because if its something other than the clutch or fan then an e-fan will not help. The stock clutch fan is more then enough for the car and swapping to an efan is not an upgrade like many think, just a side step in the wrong direction right now. Especially since you say you don't have enough powor.

Check out this page and it may help you find the anwer.
Cooling system overview and troubleshooting

Also here is a little something on the E-fan as well.
The Electric Fan

 

yeah, only get a fan if your stocker is toast for sure (which is what you thought).

 

Get an s4 (1986 to 1988) temperature gauge or an aftermarket gauge. All that pressure is probably coming from the engine overheating without you knowing it.

A bad overheat (no coolant left) is an easy way to destroy your engine. Be careful.

To test a fan clutch: With the car off, turn the fan with your hand. It should not freewheel. It should turn, but there should be a bit of resistance. Also check the belt tension on the fan. A long secton of belt should deflect roughly 1/2"-3/4" when you push the middle with your finger. If you can't get a fan clutch and have to get an efan, you can pickup one of those $40 Walmart boxes to start your car when your battery dies. Shouldn't need to jump it too often, though a better long term solution is to upgrade the alternator. Also get a really strong efan if you get one, b/c even the best isn't as good as the stock fan clutch.

Besides that and any hoses/etc. you haven't checked, the only major part you haven't replaced is the water pump. But it sounds like it's the fan.

Minor stuff for later: Once you've dealt with the major problems and you have some free time, get an OEM thermostat. Thermostats that you pick up at the local auto-store won't last as long and even before they fail and make you overheat they'll run a little hotter than normal. Also get a Lisle funnel to easily & effectively burp all the air out of your cooling system. Do a forum/google search to find it. Finally for a little better freeway cooling, check the foam around your radiator (if you een have any left) and fill in any gaps so that air won't go around your radiator. For the same reason, replace the plastic tray under the engine bay if you don't have one.

 

Good suggestions guys, thanks. And honestly, There probably isn't any foam around the radiator. When I swapped out the radiator the first time, It all just fell out, and I didn't worry about it. I'll definitely replace it. Today, I'm swapping out the water pump to see if it has any effect. Maybe the impeller is busted or eroded, and I'm only getting partial flow. Also, some info I didn't mention, when the car is warmed up, the heater only works at about 1500rpms (it blows cold below that). Does that change things any?