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So...uh...it overheated...

DesertSprite

Jedi Warrior
Offline
Hello once again,

Okay, well, here's the situation. My Wife and I were driving back to Salinas today in the Sprite and everything was going just fine. The Sprite was humming along at about 3750rpms, oil pressure was fine, temperature was fine at about 70 degrees celsius. Then, I noticed some movement on a gauge out of the corner of my eye. I looked over to see the water temperature gauge start flying up over 110 degrees celsius. /ubbthreads/images/graemlins/shocked.gif Holy crap! I thought to myself, the gauge must've broken or something. I tap the glass, but it doesn't correct itself. Next thing, I start to smell something "hot." You know that smell? It just smells like heat.

So I shut it off going 70mph on the freeway and pull over. I pop the hood, expecting steam to come flying out or to see the radiator spilling it's guts on the shoulder of the highway. Nothing. I hear a bit of dripping and see the overflow reservoir spout dripping some coolant on the ground, but nothing amazing. I put my ear next to the reservoir and I can hear it boiling inside. Bad. /ubbthreads/images/graemlins/pukeface.gif

So, we sit there and let the thing cool down. I'm thinking since we're only 4 miles from home I could limp it there. First, I start it up to see if anything is obviously wrong with the car. It doesn't seem to be doing anything dramatic and the temperature gauge isn't rising as it idles. Although, the "prepare to walk" light is flashing on and off at regular intervals. ??? So, we drive maybe a half mile and it starts to fly back up. The "prepare to walk" light is now on constantly. Shut it off again. Pull over. /ubbthreads/images/graemlins/cryin.gif

By this time, a CHP officer sees us on the side of the road, pulls over and calls a tow truck. Get it home, can't believe I just solve my ignition problems only to have this happen.

So...anyone have any diagnosis? I think it might be the water pump. There wasn't any mass exodus of coolant anywhere along the highway or steam coming out of strange places. Should I be worried about having warped the head or anything almost as bad as that? /ubbthreads/images/graemlins/pukeface.gif

Well, I guess she's headed back to the stable for a while. Again. /ubbthreads/images/graemlins/rolleyes.gif

Joel
 
Joel, if by the "prepare to walk" light, you mean the ignition warning lamp, check your belt condition and tension to see if it didn't loosen up. Slippage here can be worse at speed, and neither the alternator or water pump will be turning properly. I doubt seriously that you did any damage with a transient overheat like that, if the gauge only went to 110 or so.
Jeff
 
Water pumps are about 40 bucks, change it. Oh yea, and belt and hoses while you are in there>
 
I agree with Jeff, look at your belt / fan / water pump. The charge light indicates an alternator issue and that in combination with the overheating point to the belt. I had an alternator bolt loosen up (OK, break) which relaxed the belt and caused it to slip at speed, but would turn fine at low RPM. I wouldn’t think that the temperatures and duration you described would do any permanent damage.
 
Don't think I ever had a loose belt that did not make a lot of noise?
 
I overheated my Midget once. Very similar situation. My problem was that I had been topping up the radiator too often with water. My water/antifreeze ratio was all out of wack and then the car started running hotter and hotter. Everytime I overheated, more water. No one had ever told me that anti-FREEZE was also COOLANT. Did I mention I was 16? Ok, so I was stupid! But now I know and knowing is half the battle.

Also, as a side note, shutting it down when it is that hot can be the worst thing to do. It stops the fan turning and then besides having really hot coolant IN the engine, you now also have zero air flow TO the engine to cool it down. The best thing to do is take your foot off the accelerator, coast down, leave it at an idle until it cools, OR, if you have extra coolant with you, you can CAREFULLY remove the radiator cap aand SLOWLY add fresh coolant. You never want to shut the engine off if you're going to add more water or coolant because it would be like taking a frozen glass and putting it into a pot of boiling water. KA-BLAMMO. Cracked block. /ubbthreads/images/graemlins/cryin.gif By keeping the water circulating, it disperses and cools down the engine evenly. But of course, the most important step is to find out WHY it is doing that and fix it. In my case, the problem was that I had also been told that the car would run cooler if you took the thermostat out completely so the water could flow more freely.... also WRONG! The thermostat is CRUCIAL to assuring proper flow and proper cooling cycles.

Luckily my engine survived and I am still driving my Midget today having learned all of these important tricks and tips. I hope you and others may benefit from them and I hope you are able to solve your problem.

JACK
 
I'm not up on how long your car has been out of circulation. My guess is some stoppage in the radiator. Have you had the radiator cleaned/rodded out recently? I once fried the motor in my late Simca due to the same problem. I didn't notice the problem early enough because it was behind me! It sounds like you prevented any major damage.

Good Luck
Steve
 
Hello everyone,

Thanks for the replies. I think the first thing I will tackle is the belt problem. I just re-installed the alternator about a week ago and I did feel that I wasn't getting enough tension on the belt. But, I couldn't figure out how to get anymore out of it. I tried using a screwdriver to leverage against the alternator to pull it taught, but didn't work so great. Any ideas?

Although, I didn't hear any loud screeching noises that would indicate a slipping belt. Should I have heard something like that?

As for the radiator, it has not been drained or cleaned out since I have owned the car (November '05). I think just for good measure I should drain it and look at replacing any hoses that look suspicious. I'm assuming to clean a radiator you have to buy some sort of crazy corrosive liquid, slosh it around in there for awhile and see what falls out, right?

I'll check the belt first, then tackle cleaning out the radiator and replacing cooling system parts. Would it hurt to just go all-out and replace the water pump, thermostat, etc.? They don't seem to be that expensive in the Moss catalogue.

Thanks again.

PS - I did see some bubbles coming out of the water pump elbow (I think that's what it's called) on top of the head. Very small bubbles coming out rapidly.
 
Think about a bit smaller belt, they do come all sizes you know of course. A half inch makes a big difference.
 
[ QUOTE ]
Hello everyone,
PS - I did see some bubbles coming out of the water pump elbow (I think that's what it's called) on top of the head. Very small bubbles coming out rapidly.

[/ QUOTE ]
This "could" put a whole different slant on the problem. It sometimes means a combustion leak into the cooling system. It is guaranteed to cause cooling problems. Many shops can do a quick chemical test on the coolant to detect combustion byproducts in the coolant. It's an easy test to do. If by chance this is the problem, no amount of bandaids or other parts changing will really correct the problem.
D
 
Thanks for the heads-up on that Dave. So should I just take a bottle of the coolant down to NAPA to have it checked out?

IF there is a combustion leak...what does that mean?

Jlaird - where can I find the different sized belts? How do I know which size I currently have?

mahalos,
Joel
 
My first thought with the bubbles was that the gasket at the water elbow was weak and was letting the expanded coolant leak out, kind of like the expansion reservoir lets it drip out onto the pavement. Albeit, the water elbow shouldn't be doing that...

Joel
 
Hi Joel,
I think I misinterpreted what you said. Bubbles internal to the cooling system could indicate a combustion leak. I think I understand now that the bubbles are from inside to outside which would be an entirely different matter. Disregard my previous note. Sorry,
D
 
Napa will have literly a 100 or more belts on the shelf, they can measure the one you have as well, in fact it should be stamped on the belt. Just take what you have in and tell em you need one just a bit smaller 1/4 or 1/2 inch at best.
 
Dave - no problem. Thanks for the input though. But I have to say, you did scare me for a moment.

Jack - sounds like a plan. NAPA has been kind of hit or miss with me lately, but I doubt you can screw up measuring belts.

Joel
 
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