Can You Help Me Stop Overheating?!!

[JohnnyWadd]

Hey, guys. I'm about to embark on a project to help a friend figure out why her car is overheating. It's a 1992 Talon 2.0L Non-Turbo. She knows I'm a DSMer (though she doesn't call it that), so she enlisted my help. I took five minutes to look at it, but I didn't get very far into it, yet. I figured I'd post what I know so far and see if someone can give me a little insight as to what to look at. Maybe that'll make it a bit easier on me once I do dive in.

Anyway, the girl called me and told me that someone had told her that the water pump was out. I asked her how sure they were, and she said they were positive. So, I asked her if it was leaking any coolant from anywhere. She said "no". In my experience, a bad water pump leaks because the seal usually goes bad. Could it still be the water pump, even though it's not leaking? I've never seen a water pump just stop circulating. Hell, even when they leak, they usually still circulate, don't they? And the bearing can't be seized up. Since it's run by the timing belt, I'm sure it would've shot that bitch out of there, then I'd be in major trouble.

So, I went to the car and started her up. I only let her idle for five minutes in the driveway. I never took her out on the road. As she sat idling, sure enough, she started to get hot. As the temperature rose, though, I noticed that the cooling fan never kicked on, even though the guage approached the red line. I decided to try and jump that temp switch to see if I could kick that fan on. I know there are a couple of temp sensors on that car. The only one I messed with is the one on the thermostat housing. Is that the right one? Is that the switch that's responsible for cycling that cooling fan off and on? If not, where is it? On the radiator?

Anyway, I disconnected the plug and tried to jump across it to kick the fan on. Nothing happened. I them messed with the circuit breaker for the fan on the fuse block. Took it out, then put it back in. Still nothing. I plugged the temp switch back in and kind of played with the wires a bit, but still was getting no love from it.

Then, as I was going around to the driver's side to make sure I wasn't running it too hot, the fan kicked on all by itself. Seemed a little late to me. I felt like it should've been running much sooner. It had been running for quite a while and hovering near the red before it decided to comply. Not sure if it started because of what I'd done or not. Anyway, I watched the guage, and it dropped to a more reasonable level, but then it decided to start rising again. I decided to kill it before I got it too hot. Then we be really screwed.

So, what do you guys think? I think that there's something wrong with that fan or the switch or the relay. I don't think the pump is bad. If that water wasn't circulating, I don't think the temp would've dropped at all when the fan kicked on. That is, unless the temp sensor for the guage is near that fan, and it was reading the temperature of the coolant near where the fan was cooling it down. But, then if it wasn't circulating, the coolant in the radiator wouldn't be hot at all, right?

I'm a little confused. I'm guessing if it was strictly the fan, it would run much cooler at highway speeds, right? You know, with air passing through the radiator. Let me know what you guys think. As soon as I get a chance, I'm going to dig deeper. I'll post what I figure out.

Thanks for reading this, and I thank you in advance for any advice you might be able to give.

Jon

[AWD4G63T]

The thermo fan switch is at the bottom or the radiator on the pass. side although I'm not sure what your problem is. I had my thermo fan switch go out and the fans did not come on at all unless of course I turned the A/C fan on or jumped the relay terminals with a toggle switch. You could try taking that relay out and replacing it with one of the other ones and if it works than get a new relay. Or, pull out the relay and jump the terminals with a toggle switch or T-pins and some wire to see if it'll kick on.

Thermo fan switch is $42-$47 if I remember correctly.

That's the extent of my knowledge, LOL!
Feel free to flame away!

Jesse

[game-hunter]

Ok the stupid questions first. Are you sure there is enough fluid in the radiator? Take the radiator cap of and check if you see fluid, of course be sure to do this when the car is cold. I’m not talking about the overflow tank. You may also want to start the car and warm it up with the cap off to see if you get any fluid movement. It will overflow if you let the car get too hot and the thermostat is working. If it doesn't overflow and you don't see movement even when it's hot you've probably got a bad thermostat or pump.

If the above checks out fine and the car still overheats even when the fan is on check to see if she has anything blocking the front of the radiator. Sometimes you'll get a lot of crap between the A/C condenser and the radiator preventing proper cooling.

[92laserawd]

Ok, it has been my numerous experiences that you need to start with the cheapest thing/s first. 1st Change the thermostat. I would also recommend doing a radiator flush. Go buy the "radiator flush" from the auto parts store and follow the directions. Make sure that you have the correct mixture, which is usually 50/50. Check with the vfaq.com to make for sure. Most people tend not to wash their engine at the car wash, which by the way, being somewhat of a back yard mechanic really is an annoying thing to deal with. Any how, take it to the car wash, and wash the engine off with the tire/engine cleaner and then wash with soap and then rinse. Getting all the crap off the engine lets it "breath" better. Do not wash it when it's hot or really hot. Washing your engine also helps stuff from deteriorating as quickly. I would also change your upper and lower radiator hoses.
If that stuff doesn't help, then you will need to look at getting a new water pump. While your in there, you might as well change all the belts and timing belt too, that way you won't have to do it for a while.
You might also see if her radiator has a pin hole in it. It can be really small and not drip on the ground. You might even have a radiator place check the flow of the radiator to make sure that it's flowing well enough. They shouldn't charge you for that.
If that still doesn't help the over heating problem, then you need to see if maybe her head gasket took a big crap. If that is the case, I would seriously recommend looking into who can do that for the best price, unless you are sure that you can do it your self, and have all the correct tools to do so. If you have to end up doing a head gasket, look on the bright side. You changed a lot of stuff that should be changed on a regular basis anyway. So you/her are a lot further ahead. take care and good luck. Oh yeah, and I would also suggest looking into that fan problem too, because her fan should turn on shortly after it gets to running temp. Wade ;)

[JohnnyWadd]

Okay, I thought I'd update you guys a little. I decided to just go ahead and buy this car from the girl who owned it. She only wanted $450, and I figured that even if I can't make it stop overheating, I can always part it out and get my money back. Probably more, actually. Didn't do a whole lot to her yet. I went to a couple of concerts out of town this weekend, so that absorbed most of my weekend. It was worth every minute, though. Sevendust Rocks!!!

Anyway, I went out to play with her a little bit today. Didn't get a chance to do too much, but I did tinker around a fair amount. The first thing I did was to take off both the PS and the Alt belts so that I could play with the water pump pulley to see if the bearing was bad or the shaft was messed up. It didn't feel like anything was wrong to me. Spins freely, makes no noise, and has no play. So, I'm guessing the bearing is okay. I didn't take the timing cover off to inspect the weephole, but there's no evidence of leakage anywhere below, so I'm guessing the seal is okay as well. This leads me to believe that the water pump is okay.

Next thing I did was to pull out the dipstick to see what color the oil was. It didn't appear to be a milkshake to me. In fact, it was quite black. Could use a changing. It was about a quart too full, so that's a problem. I also started her up to check for white smoke from the exhaust pipe. Didn't see any of that. So, I'm feeling that she's doesn't have a warped head or bad head gasket.

My next step was to check the coolant level. I opened the filler cap and couldn't see any coolant at all. I had an empty two liter soda bottle that I filled with water in order to fill up the system. I was going to use Anti-freeze, but I ultimately decided not to, considering that I might have to dump it all really soon if I find out the the water pump or thermostat is in fact defective. I'll definitely change that before winter hits no matter what I figure out. It took almost 2/3 of the bottle to fill it up, but that was before I drove her to get out the air pockets. Oh, and I also forgot to check the level of the overflow tank.

The next thing I did was start her up. I let her idle for quite some time (maybe 20 minutes), and the needle stayed right where it was supposed to be: pointed pretty much straight up to 12 o'clock. I didn't notice at this time whether or not the fan was cycling on and off. However, since it wasn't running anywhere near hot, I was beginning to think that maybe the only problem was that the coolant was low.

So, I decided to take her for a spin around town to see what happens then. That's when trouble started to come into paradise. I didn't take her on the highway at all. In fact, I probably didn't get much over 35 mph. She started to get hot, though. I don't think I'd driven further than a mile and the needle was starting to approach redline. When it got close, I turned onto a side street and shut her down with the intention of starting and stopping the engine to coast home. I shut her down the first time and coasted a ways. Then, I restarted her, and was able to make it all the way back home without having to kill her again. She was starting to warm up, though.

When I got back to the house, I decided to let her idle to see what she'd do. She cooled back down to normal operating temp (12 o'clock) and stayed there the whole time she was idling. I let her idle for probably another 10 minutes. I also noticed that the fan was cycling on and off as it was supposed to. After a while, I decided to take her for a spin again. Once again, it didn't take long for the needle to approach redline. This time, when I turned onto the sidestreet, instead of shutting her down, I pulled over to let her idle. Once again, she cooled down to normal operating temperature and stayed there. It took about 10 more minutes for her to cool down.

When I got back, I shut her down long enough for her to cool, then opened the radiator cap again. The coolant level was down again, but it didn't take much to fill her back up. I also decided to check the overflow tank. It was pretty close to empty, so I filled it up as well. All told, it took about 1 1/8 2-liter bottles of water to fill up the cooling system. For you non-metric types, that's just a shade over half a gallon of water.

So, what do you think? Since it cooled down to normal operating temperature every time I let her idle, I really don't think that the water pump or the thermostat are bad. I also think that the coolant switch for the fan is okay, since the fan was running. But, the fact that it would heat up when I'd start driving puzzles me. Do you guys have any idea as to what you think would cause this? Any suggestions you could give would be greatly appreciated.

Thanks for reading. I appreciate all of your guys' time.
Jon

[Tofu4G63]

You say you dont think it is the thermostat. You didnt do any kinda of check on the t-stat like taking it out and seeing if it moved freely (not that I read at least)

This kind of sounds like the t-stat since it does it when you are driving. At idle the fans are probably cycling more often than normal to keep the temps down (plus no load)

Throw in a new thermostat. Very cheap.

[JohnnyWadd]

Do you guys think a leaky radiator cap would cause it to run hot? I know people often neglect that part of the cooling system.

Jon

[Tofu4G63]

Yes...... another nice cheap replacement.

[JohnnyWadd]

All right, guys... I think this car might have much bigger problems, and maybe I shouldn't have dropped $450 on her. I've owned it for two days, and already thinking I should kick myself in the ass for squandering my cash.

First off, I decided to pull the thermostat out of her to see if I could keep her cool while running down the road. And, before you ask, no I wasn't planning on leaving it that way. I know it's not good for the car to run it without a thermostat. Anyway, the first thing I noticed is that there was about 1/8 inch of gunk on the thermostat all the way around the opening. I didn't think it was motor oil, but to be sure I ran down to a local radiator shop to ask them what they thought it was. The guy told me what I thought he would. He told me that he thought it was stop-leak. Like Bar's or something similar. Evidently, this thing started leaking, and rather than fix the problem correctly, someone threw a bunch of stop-leak in the cooling system.

So, this presence of gunk leads me to believe that the inside of the radiator looks the same.

Anyway, after I took out the thermostat, I decided to take her for a drive and see if she ran hot. At first, she did okay. It ran for a couple of miles (city driving) at normal operating temperature. By that, I mean that without a thermostat, it ran at the temperature it normally runs at with a thermostat, not less, as it should have if the thermostat were the problem. I let her idle while talking to the radiator guy. It still did fine. Then, when I started coming back home, it started getting way worse. The guage pointed to the start of the red line, so I shut her down. I decided to limp her home by starting her, getting her up to the speed limit, then shutting her down, taking her out of gear, and coasting down the side streets. I made it home this way without overheating her.

So, anyway, there's no water in the oil pan, and no oil in the cooling system. However, the radiator guy told me that what these things do when the head gasket goes bad is leak between the combustion chamber and the coolant system. So, the compression increases the pressure in the cooling system, forcing coolant out (usually by creating new leaks in the cooling system). The only upside is that I can find no evidence whatsoever of cooling system leaks. Not surprising, considering that there's an eighth of an inch of stop-leak in there.

So, let me give you my logic, now. If you guys see a fault, point it out. If you have another idea, shout it out. If you agree, give me some words of encouragement. I'm thinking one of two things: bad head gasket; or so much stop-leak inside the radiator that neither the fans nor the air coming in at driving speeds can begin to cool the water. Since there is no coolant/oil exchange between the oil and cooling ports, I'm thinking that with a compression test, I'll be able to tell if the pressure is leaking back into the cooling system. Also, if I did a compression test with the radiator cap off, wouldn't I see bubbles shooting up through the water at the filler hole? Pressure will release at the point of least resistance. If I have the cap off, that will definitely be the point of least resistance.

If I find no head gasket woes, I would think that I can assume that the stop-leak is the culprit. Is there anything that I can run through there to get rid of all that shit? I don't think that just flushing it will drive that stuff out. If not, I'll just replace the radiator and see if that helps it run cooler. No, not with a new one. I'm not going to take that big of a chance.

One more thing of note. When under load, there's a bit of a rattle coming out from under the hood. Can't tell where it's coming from. It doesn't do it when I rev the engine. Only when under load. Not sure what it is. It's not really a knock. Not loud enough. Like I said, it's a bit of a rattle. You know, it almost sounds similar to the rattle a diesel engine makes when operating normally, though not near as loud. What do you guys make of that?

Thanks again for your help, fellas. I appreciate anything you can give me.
Jon

P.S. I hate all forms of stop-leak. They're evil. They should be eliminated to force people to actually fix problems that arise rather than just putting a band-aid on something that needs a tourniquet. I think that they were invented by and for people that want to mask a problem before they rip off the next owner of their car.

[AWD4G63T]

I'd bet it's the stop-leak. That stuff will clog and reduce the flow of coolant through the radiatior. Replace that radiator and get someone to do a flush on it using a BG machine or something, maybe even before the new radiator. Thermostat as well!

Jesse

[92laserawd]

P.S. I hate all forms of stop-leak. They're evil. They should be eliminated to force people to actually fix problems that arise rather than just putting a band-aid on something that needs a tourniquet. I think that they were invented by and for people that want to mask a problem before they rip off the next owner of their car.[/QUOTE]


I definately know what you mean with the stop leak. People do that kinda crap with Fix-a-flat too. Fix-a-flat will eat the finish off any wheel. It takes a while for that to happen, but none the less it still happens.

I would agree that flushing would be a great start, and then do a compression test. If one cylinder leaks down, then you obviously need a head gasket. I would also replace the upper and lower radiator hoses.

Not to be mean or anything, but it sounds like you WANTED to buy this car from that girl. Maybe to make some money. Besides that, you knew that the car was over heating. I do however agree with you on the putting band aids on to mask problems. That is why you should look over a car extensively BEFORE purchase or have someone else look at it.

[JohnnyWadd]

I didn't really buy it to make money. I bought it to break even. I know that sounds stupid, but my logic goes back to my stolen Talon. By purchasing this car, I've got another car to pick and choose parts from for re-assembly of my car. That means that I could take the most cherry parts from three different cars to come out with the best finished product imaginable.

Now, as for that car, I figured that $450 was a low risk. I figured if it was a simple problem and I could fix it easy, then maybe I could make some money. If not, I figured that I could probably resell it for what I had in it. If that was a bitch, then I figured I could part her out. Either way, my main motivation is to pillage parts I want and come out as close to even as possible.

Jon

[JohnnyWadd]

This overheating job is going to take a backseat for a few days. The holiday will delay me some, but I'm going to spend most of the weekend putting my stolen car back together. Once I'm done with that, I'll resume the task.

Thanks for all your input. I'll let you know what's up once I get back at this one.

Jon

[JohnnyWadd]

All right, I know it's been a while, but I was finally able to play around with this thing again. I took it to my buddy's mechanic shop, and it didn't take long for us to determine that the head gasket is shot. Problem is, I'm moving back to San Diego next week to return to grad school, so there's no way that I'll be able to work on it. So, I think I'm just going to get rid of it and try and get my $450 back.

How would you guys recommend that I go about this? Is eBay a good idea for a car that doesn't run (at least not correctly)? Or should I stick with the local papers? The car itself is located in Lincoln, Nebraska. If you know anyone close who's interested in the car, let me know. It's a 1992 Talon Non-Turbo 2.0 Liter. The car is quite decent. Pretty nice shape and not all that high of mileage. If someone has the time to put a little TLC into it, it'll probably work out nicely for them. I don't have the time and I already have a DSM that I'm in love with, so this car is expendable to me. If you know anyone who wants it, let me know. Have them drop me a line at jhieb1@hotmail.com or call me at (402) 770-1118.

Thanks
Jon

[Hal]

You can try to ebay the car, but it might be worth more as a parts car.

Engine, ecu, wiring harness, sensors, interior trim/panels would all be pretty easy to sell and would net you more than $450.

The engine has a bad head gasket, but the head alone could net you over $100 on ebay. Likewise the short block should be good for another couple of hundred.

Hal