I just rescued a 93 touring from Va yesterday, was driving it home to Pa and everything was fine on the highways, got it close to home and the temp guage starts climbing REAL fast near hot and then just drops down to where it's supposed to be. Not a gradual fall it spikes back down as fast as it rised. I'm new to the 3rd gen thing. It's a whole different ball game than my 2nd gen....any help or idea gentlemen? Thanks

 

Are you talking about the stock temperature gauge?
It's not very sensitive, it usually won't start moving until around 230 degrees where you've already overheated your engine. If it moved up very fast and back down as quickly I would dismiss it as a problem with the sensor or the gauge. How much of a time frame was this in?

You need to get an aftermarket temperature gauge right away. Oh and how many miles on that motor?

 

The timeframe was within 2 or 3 seconds, it was up and down. and 43k miles. Thanks for the help

 

You might check the connector to the sensor or the continuity of the wiring.

I've never seen my stock gauge do that, but my aftermarket gauge did that when the wire I ran for it was failing. As soon as the gauge didn't get a signal from the sensor, it shot straight up to the top. Once it regained connection, it dropped back down to normal.

 

maybe an air bubble?

 

Usually a failing thermostat or you had a huge air pocket in the engine.

This symptom shows up when your o-rings are failing too.

 

Wrong.

Sounds like you have a loose wire.

 

Thanks gentlemen...I hope you're right and it's just a loose wire...if it's an air bubble...can I just burp it?

 

So Mr. Right, explain to me why I'm wrong since you're such a

Consider this: I probably have more experience than you at the o-ring failures as I have had 2 engine go this way. This symptom accompanied both engines. They occurred after the coolant rushing sound in the glove compartment.

Consider this also: the connector for the temp gauge is a single wire positive lock connector. And if it comes loose, how did it magically reconnect itself in a locktight manner so that the guy doesn't see this symptom?

 

Thank you so much for the nice gesture. Just because I disagree with you, there is no need for such an immature response.

I won't bore you with how many years that I have been working on cars, and rotary engines. Lets just say it is significant. The FACT is, engines don't suddenly spike in temperature, and then magically drop back down in the 2 or 3 seconds that has been mentioned in this thread. Engines take time to cool off. Even if there were a bubble in the cooling system, it would be roughly the same temperature as the coolant. It is a myth that small bubbles will spike your temperature.

You mentioned that your temps went up drastically when you had a seal fail. That could account for a rapid rise in temperature. If that were the situation, the temps would NOT immediately drop in the 2 or 3 seconds that was mentioned in this thread. You failed to include that in your reply.

You asked for an explanation, that's it. I hope you learned something. I won't respond with a childish gesture like you did.

 

buy aftermarket water temp gauge asap!

 

The more you think you know, the less you do. As to childish gesture, I'm still a kid at heart..

My gauge did exactly that by the original poster, it climed towards "H" on the gauge and then dropped down. Later on, as the seal deteriorated, the buzzer went off with the rise in the stock gauge towards H. Within 5-10 secs. they both return to normal.

My theory? combustion gases leaked past the o-ring into the cooling system of a sufficient amount to cause a rapid temp rise. Remember, the sensor for the stock gauge is right on the block, not in the coolant so any rapid temp rise will be seen immediately.

And this declaration that it's a myth that bubbles will cause a rise in temp. Ain't no myth. A bubble in the cooling system, if not from combustion gases, is usually vapor. Assuming the bubble is coolant vapor, how does coolant changes its physical state? Heat input. Therefore, vapor is not the same temp as coolant but actually higher such that they're called saturated steam and even superheated steam.

Moreover, how can you conclude with such absolute certainty that temp gauge can't go up due to air bubble in engine? that engine temp can't rise that fast and return to normal?

Sorry, but the only thing I've learned is that your reasoning haven't taken into account other causal mechanisms that explain for the temp spike on the stock gauge. Remember, the guy asked for any and all ideas, not some absolute answer.

 

You are not overheated at 230°F because just at 226°F your fans come on -on 210° with parking lights on- so 230 is hot but not overheated.

When you reach 250°F your engine is overheated. My personal thinking is that is better to keep your temp between 190° and 210 °F.


I think you have an electrical problem with that gauge.


RT

 

So the guys temp gauge bounces up for two seconds, and you think he needs a rebuild due to coolant seals failing. Maybe you should open up your own shop. Of course, you wouldn't have any return customers.

Wrong again. If there is a bubble in the coolant system, that is not from combustion, the coolant will act to reduce the bubble to the temperature of the coolant. In addition, the coolant flowing thru the engine will reduce the metal around the cooling jackets to close to the temperature of the coolant. So don't try to come up with some other BS about the engine superheating the air in the system. It just doesn't work like that.

Another juvenile gesture. Do you think anyone who isn't an imbecile will be impressed by that.

 

yo!

wonder if ur belt is slipping?

removed airpump and no pullies?

yes temps dont change that fast but does the guage move that fast ? might be slow to react.

 

hmmmmmm, i had a similar problem, with spiking temps and the check coolant light turning itself on and off every comple of seconds. finally my car just dumped all of its coolant onto my driveway, and at the moment, my car is in for a rebuilt.
im not sure if its exactly the same, but if it happens again, or you dont want to take the risk, maybe you should go get it checked out if you dont have the mechanical knowledge to do it yourself

 

Change your Thermostat ! This is exactly how I lost my first engine !! I **** you not.....needle on the stock temp gauge was bouncing up and down like the oil gauge every now and then. The T-stat is sticking. Change it now before you melt your motor.

 

I was about to post that actually. My wife's jeep did the same ****. I just removed her t-stat and said **** it.