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RX is overheating!


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It has been overheating and it does not appear to be the head gasket, my oil looks fine. I have also replaced the thermostat and that didn't help. It is not leaking coolant. When I start the car it runs normal for a few minutes and then temerature starts climbing after about 5 min.

 

A couple issues with the car I'm wondering might be affecting it;

 

The heater only turns on about 20% of the time.

 

I am not getting any boost, I think due to a leak where the (up-pipe?) connects to the manifold by the passenger side front tire.

 

Any ideas?

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Im thinking I'm gonna drain the radiator and refill it. Also could you elaborate on the heater core issue. Could that cause the car to overheat and should I get a new heater core? I know my heater fan doesnt turn on most of the time, I dont think its a bad switch though, I think its a bad fan motor maybe

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Test if it's the thermoswitch. Place a small jumper wire or just a paperclip or something across the terminals that connect to the thermoswitch. Do this with the key on and the fan should fire up. I've had problems with poor connections at that clip. If the fan doesn't fire up, then run 12 volts directly to it. If it still doesn't fire then that's your problem.

 

If your electric fan isn't working that can cause it to get hot for sure. Check your Coolant temp sensor. The 2 pole one on the back of the intake. That's what the ecu uses to decide how rich to run and what to set the timing to. If it is bad, reading cold always the ECU will run the engine rich and advanced timed, causing high temps.

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Is that 5 minutes of driving? I'd fix your exhaust leak, if your turbo isn't boosting, you're engine may be working too hard. Also, your turbo has coolant lines running to it. Check to see if the turbo is shot. Do this by taking the downpipe off and check for play in the turbine. There should be very very little to no play.

 

Justin.

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when you say "heater fan doesn't come on" are you referring to the heater fan, or the radiator electric fan? Because Gloyale is referring to the electric radiator fan. The thermoswitch in question is on the passenger side radiator tank, usually down fairly low.

 

Try taking your hand and moving it gradually across the surface of the radiator when the car is warmed up. If you feel any spots that are cooler than most of the radiator, then you have found a clogged spot. I am betting that your radiator has more than one of these cool spots.

 

Did you use an OEM thermostat? I hear that OEM is the only way to go for REAL safe reliability.. but I run without one, so thats hearsay. (tropical weather FTW) Also, check your radiator cap to make sure it is sealing good and tight; a new radiator cap is cheap and almost always worth it.

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I was talking about the heater fan (under the glovebox) but I havent noticed if the electric radiator fan is working properly so I will check that thermoswitch now anyway, and no it's not an oem thermostat but I doubt that will be a problem???

 

I'm hoping it's the exhaust leak because the car heats up after 5 min of driving.

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Ok so I jacked up the rx, the exaust gasket on the passenger side has 1 bolt out and the gasket has pivoted creating a large exhaust leak, reson why I have no boost. The car idled fine and didnt overheat. I'm guessing this is why it overheats when I drive it. I have 2 questions:

 

1) To replace this gasket (I already have a new one and a new bolt) Will I have to unbolt the whole pipe from the exhaust manifolt and turbo, and replace all the gaskets?

 

2) When SHOULD the second electric fan turn on? It didnt turn on while it was idling.

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You should read this thread about replacing the exhaust studs. It can be done without removing the exhaust pipes. In fact it is very tough to remove that exhaust pipe(uppipe/crossover) with the engine in the car. You have to jack the motor up a bit really. But yeah read this, it's a long thread and there's some bickering but you'll get the jist of how to solve a stripped out exhaust stud hole. I'm sure yours is and that's why the stud fell out.

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You should read this thread about replacing the exhaust studs. It can be done without removing the exhaust pipes. In fact it is very tough to remove that exhaust pipe(uppipe/crossover) with the engine in the car. You have to jack the motor up a bit really. But yeah read this, it's a long thread and there's some bickering but you'll get the jist of how to solve a stripped out exhaust stud hole. I'm sure yours is and that's why the stud fell out.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=73815&highlight=helicoil

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Thanks, fixed the exhaust leak, now turbo spools. I drove the car about 8 miles and it heated up close to red temperature, I popped the hood and the second radiator fan was not on. I'm guessing thats part of the problem but my roomate says it shouldnt have to come on for that short of a drive. He says I must have a radiator, or head gasket problem.:mad:

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It'll be a Head gasket problem if you bring it to the red zone for long. Do a compression test if you can.

If it has good compression, this is what I'd do:

-replace thermostat

-replace thermoswitch for electric fan, or run a switch from the fan to the inside of car, so I can manually turn it on

-Check timing (20'btdc with two green connectors under the dash connected)

-Run actual antifreeze

-If it still overheats, have the radiator tested.

 

How does the radiator look by the way? Like wear and tear wise.

 

Bad Compression numbers, you probably popped a head gasket or two.

 

But with Subarus, it's usually the easiest fix. So easy, that we (Or at least I) tend to miss the solution because it's too easy.

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Thanks, fixed the exhaust leak, now turbo spools. I drove the car about 8 miles and it heated up close to red temperature, I popped the hood and the second radiator fan was not on. I'm guessing thats part of the problem but my roomate says it shouldnt have to come on for that short of a drive. He says I must have a radiator, or head gasket problem.:mad:

 

 

The fan should come on any time the Coolant is over 198-205 degrees. Time has no bearing on it. When it get's hot, is the radiator hot? both radiator hoses hot? If not then you have no circulation. Either the thermostat is sticking closed, or the pump impellers have rotted away and you have no pumping action. When was the waterpump last done and has it been run with just water in it for any time?

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to test the fan and make sure it works, unplug the thermoswitch (the small two wire plug going into a copper plug looking thingy on the passenger side radiator tank) and replace the thermoswitch with a jumper wire. With a single piece of wire bridging the connection to the thermoswitch, the ran will run any time the key is in the "ACC" or "ON" position.

 

*I* don't even use my thermoswitch; I just let the fan run whenever the car is running.

 

hth

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That would suck so bad in Wisconsin winter. I block off most of my radiator and remove my clutch fan

vat iz dis "veenter" ting of vich I hear so much???

 

I loves my sunshine. The only time it sucks is when you are in an overheating car and have to use the heater to help keep it cool. (at least the car in question wasn't my soob)

 

Anyhow, as a temporary fix, there is absolutely nothing wrong with wiring the fan as I said. As gloyale pointed out, it MIGHT not exactly be an "all season" thing for some folks, though :grin:

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I have used dearons temp fix ( letting fan run all the time with key on) and am still using it on my XT6 till I can get an OEM thermostat (my dealer here doesnt want to waste their time to order me one) and a new thermoswitch..temp runs at 1/4 on the guage now at 85 degrees out..only went above once coming back from Carlisle ( Car Show) going up one of the big mountains with the AC on..went up just below half. Its an easy quick temp fix and it also helps you figure out why you were overheating. I tested my fans first...by jump wiring them and touching the battery.

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  • 2 months later...

Well apparently my head gasket was fried, I had a cracked head and my radator was clogged!

 

I tore the car apart and 1200 dollars later (in parts alone) I'm ready to put it back together.

 

I am replacing everything, I bought all new gaskets, had the heads cleaned and fixed, new bigger radiator, water pump, fuel pump, plugs, wires, distributor, and a ton of other stuff.

 

What a headache, it will be nice to have her on the road again, running better then new.

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