I have a 1985 GS with the 12A engine. I had a small leak in the radiator, which required me adding about 6 ounces of coolant after every three hours or so of driving. In order to buy a little time I added about 8 ounces (half a container) of Bar's Leaks liquid aluminum to the radiator. I have used these products multiple times during my 40 years of car ownership without any problems, but this was my first time with a rotary engine. During my very first attempt to drive the car after adding the stop leak product, I noticed my temperature gauge rising higher than normal. My gauge needle would typically stay around the 3/8 mark, but this time it passed the 1/2 mark and was continuing to rise so I parked the car to avoid overheating. I have flushed the cooling system several times with cooling system cleaners, but the car is still heating higher than normal. If I start the car and let it idle it will reach the 5/8 mark after 15-20 minutes and doesn't appear to stop rising. If I am driving the car, the temperature reaches the 5/8 mark in less than 10 minutes. My results have convinced me that adding the stop leak was a bad idea, but I don't know what steps to take to undo it. Is there something unique about a rotary engine that makes it more sensitive to these products? Does anyone have a suggestion on what steps to take to get the cooling system functioning properly? Thanks

 

There is no way to remove stop leak entirely. If you're sure the issue is the radiator having a leak, I's just replace the radiator. New radiators are getting harder to find. You could take it to a radiator shop for a cleaning and fix. Also replace the t-stat.

 

Wow, that was a super-fast reply. Thanks for the advice.

 

check to see if the t-stat is opening......there should be noticeable turbulent flow with the radiator cap off, and the engine temp guage showing slight (1/8 to 1/4) temperature

naturally, remove the radiator cap when the engine is cold, and the hoses are soft/not pressurized.

 

Sounds good, thanks for the help.

 

I wonder if your temperature sensor got gunked up and your stock gauge is giving a false reading.

You might want a second opinion, install an aftermarket temp gauge, good investment in the long run in any case.

An inexpensive sunpro unit will do the job, easy to install in the thermostat housing, posts here show how. Good time to check the tstat too.

If that's too much trouble you could use some external references, a temp gun if you have access, thermometer on the radiator, just plane observing to be sure things don't get real hot.

 

That all sounds like good advice, thanks for the response.

 

Get the radiator cleaned, change the thermostat and if it was me I'll change the water pump also ......they are cheap easy to find and swap .....

 

Okay, thank you for the tip.