I have a 92 RS convertible, 305, automatic, I recently, 3 month ago, bought from a good friend, the car was well maintained and within the last year a new radiator, water pump, all hoses, and stat where installed. I have the car 3 months and 2 weeks ago on a trip the car was running unsually hot, even driving at highway speeds. It was running about 240 to 260. I even had to let it cool down after stopping for gas, it refused to start, after about 10 mins it stared right up.

I have read most of the posting on this site about cooling problems, and the other day I put it a new 195 stat, and even drilled two 1/8 in holes in the sheet metal flange around the stat. I flushed the radiator and condensor to get out some dirt & leaves, there was a bit of crud but not as much as would cause a problem, I think.
I checked the air dam it is intact, no cracks, and seems to be at the proper angle. The fan seems to be working well, kicks on with the A/C on and when the A/C was off it kicked on at about 225 degrees. The car still ran hotter then normal after I did that work.
The car was missing the plastic cover, that covers the top of the opening under the hood in front of the radiator, by the hood latch. I found a like new part in a U-pick salvalve yard yesterday, and installed it, haven't driven the car yet to see if that helps my cooling problem, I have the dash apart working on another demon. The heater core is bypassed, I don't know if that could post any problems.
I had seen a product in AutoZone, called, - 40, it is similar to Wetter Water but claims to reduce cooling temps up to 40 dregrees, I called up the company, ProBlend (336-767-1027), the tech I spoke to was very helpful, he told me that Wetter Water even though a good produc, is alcohol based and has a very short effectve life span in the radiator, just a few months. He told me that their product was effective for at least a year, and will reduce cooing temps up to 40 degrees, I was impressed with the info he provided me but was even more impressed when I asked him a question just fooling around. I asked him jokingly if any of the Winston Cup teams use their products, he told me that virtually every Winston Cup and Nascar vehicle has 40 Degree in their radiators, and the companies R&D is done with the help of the Rousch Racing Team and Dale Earnheart JR's Team, now that impressed me more then anything.
The additive is expensive $25 for a quart at AutoZone, $19.95 at DiscountAdvantage.
Has anyone used this product, or is familiar with it, I am not able to do any expensive changes to the car at this time and hope to hear someone has used this addictive and has had good luck with it.

 

I can't say anything about the product because I don't know. how do you know you are overheating? the gauges in these cars are typically off, either by alot or a little, the only way to know your temp for sure is a thermometer. as for your car not starting back up right away after driving that could be heat soak to your starter. just a couple of thoughts. good luck

 

Thanks Red Bird, I'll check the water temp with a thermometer, my gauges are a bit flaky another problem I'm having but I think I've solved the gauge problem, poor contact at the connectors. The starter did turn the engine the time I refueled and it wouldn't start for about 10 mins, until the enigine cooled off a bit.