Ok ill be driving my car around town and the temperature reads about 200, so lets say i go into a store for about 5 mins, ill start the car and as soon as i start it the gauge reads 260!!!WTF!!!So then i start dirviving and a few minutes later the gauge drops back to 200. This has been happening every time i get out of the car for a short period of time.....could putting in a 180* thermo cause this???Whats happening??

 

Are you reading the stock gauges - which are pretty crappy for one. Aftermarket with a new sensor would tell you for sure. For the most part, its just heat soak. You run an engine for awhile, its hot, its being cooled because its running - the waterpump is pushing water around through the radiator etc.. the point is the water is moving and transfering the heat from the block. Once you shut the car off, the flow stops. The block is big piece of metal, that is hot, so for a period of time, the temperature inside will rise. It happens... you cant stop it completly. If you have electric fans, you could turn them on with a switch before you get to your destination. I do this when cruising down the highway for long periods of time, run the fan to cool everything down. If i dont, when get off the highway, the temp creeps up. You could try a lower temp thermostat i suppose. But if the car opperates within normal range while your driving, and never see it overheat or run cold... dont fix whats not broken.

 

ok makes sense nut why would it start doing it when i put in a 180 degree thermostat??

 

I'll bet your gauge reads 260°, but you aren't boiling over or you have no visible steam from the engine, right?

Sounds to me like you have a trapped pocket of air under the thermostat. You replaced the stat, you trapped some air under it. In a proper situation, the coolant heads up, the stat opens, and coolant is allowed to circulate. When an air pocket forms by whatever means, it is forced to the highest point in the system, which is right below the thermostat. Since the air pocket does not move, it cannot gain heat from the combustion, so it (the air pocket) heats at a slower rate than the rest of the coolant. (the air pocket heats via heat transfer from the coolant, rather than combustion). Since the thermostat reads whatever is directly below it, it gauges off the slower-heating air pocket and, in turn, opens when the air pocket hits 180°. So, while the air pocket may only be 180°, the coolant may very well be 260°. Then, after the 5 minutes, the air pocket finally heats up enough to crack the stat and bingo, fluid flows through and the gauge drops.

The only way to ENSURE that no air is trapped in the system is to remove the stat and drill at least 1 small hole in it. This allows a very small amount of coolant through, but more importantly, it allows for a passage that the air can be forced out so the stat reads actual coolant temperatures.

*edit* take a look at this thread and see what size holes people are drilling:
https://www.thirdgen.org/techbb2/sho...hreadid=165507

 

Ok, but it doesn't make sense to me why the car will sit for 12 hours(overnight) and it will warm up to 200 and not go over,it only hapens when i let the car sit for a short period of time????

 

now that i thought about it, it could actually be the henway.... check the henway

 

what is a henway???

 

 

Cumon im a noob....

 

5-6 lbs I'd say.

 

No, really..im young and stupid.

 

Never heard of it myself...but to be honest, my car had only one real problem... when the temp outside was hot, it seemed to 'flood' or stall in low idle. I think the problem had subsided or I would have had some sort of service. Those recalling my own Bird owning history here may recall, mine was bought with 44K miles, now it has just under 130K. It's ran pretty well for a long haul, but often even at regular height, the front feed air dam hit debris of one type or another, this had to be replaced and still has broken areas! Make sure the radiator is in good shape and the air feed from underneath. The fans would come on anytime the temp raised past 200 on stock guage. With my Cadillac, the water pump was leaking pretty good, at some points it steamed out if still running too hot. I went to water alone to keep the level up and money in my pocket...checking before each use. Keep an eye on your fluids... One eBay seller commented to me the idiot lights warn you after the fact, too late to do much remedy. I still have only stock dash/electronics and guages. Certainly nothing wrong with specialty equipment, but between those two mileage readings, they didn't become an issue. The Cad with the water pump issue had bad gaskets all around but that same motor also had over 350,000 miles!!
BILL

 

You answered it before I could get to it ya bastid.... but yes its just an old mechanic joke....

 

So there is no such thing as a henway????

 

Nope, doesn't exist. It's just a fun little joke that gets thrown around from time to time.

 

Im sorry, but there is no such thing as a henway... Just a joke

 

Ya know...just for that, I got one for you...from my own profession, home construction.
When there is a new guy getting trained in, back in the day, we would have them go get a 'board stretcher'. The fact that there in no such thing I wasn't aware of, but IIRC I came up with a tool that actually compresses large wood gaps, it's two locking clamps on a long steel pole...you set one and then move the other close and then turn the clamp screw,like a bench vice. It was close enough to count in my book hehehe
Bill

 

Yea, it's a joke - 1960s HotRod builder, think it refers to some motors he built that had over-heating problems.