1993 VX Radiator fan question
 

I think my radiator fan may not be working. The engine doesn't overheat but the coolant overheats sometimes bubbling out of the top of it. I brought it to the mechanic --he replaced the coolant with water, revved the engine some to see if the fan would come on but I don't believe it did.

How loud is the fan when it comes on? Is it hard to miss?

Yes it is hard to miss it when the fan comes on.

When I bought my VX the fan didn't work. I tested it by hooking it up directly to the battery. I would try testing it that way. The coolant should never bubble out of the rad as long as your thermostat is opening, your coolant passages aren't blocked, and your fan is working. My friend had a full grill block on his VX with the factory fan in place and the car never overheated even in 90 degree weather.

To replace my factory non-functional fan I installed a universal slim/high flow fan which weighs about half as much as the factory one an cools much more efficiently. I currently do all city driving (stop-and-go) in a humid and hot city and I never even hear the fan come on, never lose coolant, and never see the temp gauge move past half.. I would suspect something is wrong with your coolant system.

One simple test. Unhook the battery, see if the damn thing will spin by hand.

That definitely shouldn't happen. Do you mean past the radiator cap? Maybe it's a bad cap. You should also make sure your coolant is correct (the right mixture, and not stale). The wrong coolant (like water, for example) will boil at a lower temperature.

The fan is easy to hear when it come on. Mine almost never comes on.

The other day it was about 80 degrees and I was letting the car idle for a long time while I was working on various things. It took over 15 minutes of idling before the fan came on. And it didn't stay on for long.

What does your temp gauge say? It could be that your engine temp is normal, and your fan is off because it doesn't need to be on.

Yeah some cars have amazingly good cooling systems when everything is working right, I had to sit holding the throttle at 2-3000 for 25 mins in the driveway before I could get the escort's fan to activate.

Edit: BTW don't discount the possibility of a bad radiator cap not maintaining enough pressure for a "doesn't seem very hot but it's boiling over" problem.

Thanks guys.

The coolant in there was some super low temp anti freeze for the frozen north. Definitely not stale. Now I guess its mostly water since I believe most of it bubbled out of the cap and a mechanic replaced it with water for me. Last fall I did high rev driving on a few 0-60 tests and never had any problems. Last month I was late to a play and drove like a bat out of hell for 27 miles but had no problems. Last week I lent my car to a friend who doesn't turn the engine off and drives normal. The mechanic said that the CEL would not cause the car to run hotter than normal--so my friend was driving the car about 15 miles with the CEL on. I assume he drove it normal--maybe shifting a little bit high since he's not used to the VX. He said when he arrived at his destination (about 15 miles later) the car was steaming and there was green coolant fluid in the engine bay. The problem started when I was going to a bruce springsteen concert in February. But it's only happened to be me once before shortly after the Boss concert. I had been idling and driving slow in traffic waiting to get to the parking space at the civic center. Musta been about 10-15 minutes of idling and driving very slow (you know how those events can be.) Nothing happened then. When we left the concert, the car started overheating. It was again lots of idling and slow going out of the garage. I actually had the car off much of the time waiting for the traffic out of the garage to creep along. Anyway--engine DID overheat. But I found out when I finally got to a gas station with lots of slow P&G EOC to limit heating as much as possible that the radiator hose had come off. I bought a wrench and tightened it down real good. Since then it hasn't come off again, but ever since then there have been a couple instances of the fluid bubbling over. Once or twice shortly after the concert and then again this time with my friend last week. Maybe there was too much fluid in there. I filled it to the very top. People who looked at it for me kept commenting on how the overfill tank didn't have anything in it. No one knew how to get fluid to go in there. I sort of got the impression it was meant to go in automatically. So I dunno if it's supposed to happen automatically and thus there is something wrong with my cooling system.

Hope this new information might shed more light on the issue.
thanks everyone.

There should be a bypass pipe of some kind just under where the rad cap is that connects with the reservoir. When the coolant expands too much and goes over 14psi or whatever your rad cap pressure rating should be, spare fluid passes into the tank. This gets sucked back into the system from the bottom of the tank. If the bypass pipe is missing, that means it's just dumping fluid when it gets a little warm and not pulling it back in later when it needs it.