Cooling System PSA

[89fuelie]

Since summer has arrived, I though I might share a cooling system tip that I haven't seen get enough publicity. On my 89 LXi, the fans were cycling on and off about once a minute. This was on a 75 degree day, mind you with no A/C. It was one of those "Oh No" moments, as I realized the cooling system was gonna take a dump. I blew out the rad fins with the compressor, and blew out a ton of bugs/leaves/etc, but that didn't help. What fixed it was:

Bleeding the cooling system!

I hadn't done it since the last time I changed the coolant, so I assumed it was all bled out. Apparently I missed a bit. I don't think it was making the car overheat (Who knows, with our dummy gauges) but it was sure screwing with the sensors! Just thought I'd share a quick fix for what is sure to be a common problem in the coming months, at least in the Golden State.

[derolph]

Good point. I believe you're correct in saying crappy old coolant can affect temperature sensors and that can cause some erratic behavior.

I experienced a similar situation with my 88 LX-i. My son bought this car from an auction in Florida back in 1997, as I recall. It had about 90K miles on it then. The coolant was a rusty/brown color. I suspect this was corrosion caused by using little or no anti-freeze by an owner in Florida when freezing temperatures are not a concern. When my moved out west in 1999, he did not take this car with him and I became the owner. As I recall, my son had the system flushed once but the coolant was still brownish in color and the mechanic advised flushing it again soon. And, as I recall, it was flushed again sometime after that. But, still, the coolant looked brownish. In 2009, the radiator developed a leak and I replaced it. While doing that, I decided to do my own flush. I installed the new radiator, put a concrete mixing tub under the car to capture old fluid coming out from the engine, left the upper hose (which flows into the radiator) disconnected, kept feeding warm water (from house) into the radiator while running the engine. I also had an extension tube from a Shop Vac that fit into that upper radiator hose and this helped direct coolant down toward the tube under the car. I kept doing this until the color of the fluid become fairly clear. Then, I reconnected the top radiator hose and added anti-freeze to get approx. 50/50 mix in the system. Since then, the coolant has continued to look pretty good.