CLUE

Hi, I was driving with my friend this morning and I noticed the Low Coolant light had just came on, so I went home and parked it. It's a 1991 Ford Mustang GT 5.0. I checked under the hood, took off the radiator cap and there's coolant visible and it looked clean, no discoloration and it is full as far as I can tell. I also took a quick look at the resevoir (I think is the overflow resevoir?), it has a lower resevoir labeled cool and one above it labeled hot, there is coolant in the upper resevoir (labeled hot) it was just under the full line a bit, this is after it had been parked for a few hours. I noticed the resevoir cap has a line going down into the resevoir with a little plug looking thing that isn't attached to anything, should it be? There is a couple little dents around the middle bottom of the radiator (I've seen alot worse), but I can't see any punctures and I haven't seen anything leaking out of it. The coolant seems to look fine, but I was thinking of buying some radiator flush stuff and do that and change the coolant, hope I don't need a new rad! I don't have a manual, I'd like to get my hands on one soon, just got the car a few weeks back, the car was sitting for a while before I bought it, do you think it could just be clogged up even though the coolant looks clean still? Any advice would be nice, I want to get this cleared up in the morning without messing around if possible, thanks.

jthorn9

You should still bring it to a shop and have it tested under load, you may have a minor leak somewhere.

Boss_Hotrod

Try cleaning the sensor. They get gunked up over time and quite working correctly.

ITALIANO66669

i didnt reinstall my sensor so my light never comes on.

mattdel

So, what method do you have in place to warn you that you're losing coolant? Or do you just wait for the head gasket to leave you stranded...

The_Dude

My light comes on all the time as well even though I don't have any leaks. I changed the coolant and it didn't make a difference. I'll try cleaning the sensor.

9redfox3

My came on one time over the winter when it was parked in garage .I checked the resevoir it was a little low,filled with some antifreeze and the light never came on again...

CLUE

I just phoned a nearby rad place and told him what car I had and that the low coolant light came on, but that it didn't seem to be leaking and the coolant still looked fine/clean. I am going to go and squeeze all the lines a bit and see if it goes down, top up if needed, then see if it goes down again. I will give that sensor a wipe, thanks for the help everyone! Haven't owned a mustang before, so I will be on here regularly, hopefully I can help someone else down the line. If there is a leak, then it would be dumb to do a flush and put new coolant in, so I guess it makes sense to make sure first and I won't be driving that much for a week or two anyways, I'll put some cardboard under the rad as well when its parked to show any leak signs. Just to see I asked how much a flush would be and he said $150.00 (cdn$), which seemed pretty high end to me, he said they like to replace the thermostat when they do it, which most places don't but he said it is better, would that really be necessary? I didn't really understand the point of doing that. All of my tools are 2000km away unfortunately and this is just part of the process when you buy a car that has been sitting for a year or two, I need to get my tools down here and buy a jack + stands, but I can't afford all the do it yourself stuff all at once right now. If I do take it in to have it done, does anyone know a good canadian place to have this done at (example: Mr. Lube...) I'm in Vancouver BC, I really don't like bringing my car into a shop where I don't know if they'd do a better job than I would.

The_Dude

You should replace the coolant once every year or two. I replace my thermostats if I have the radiator or water pump out, or if I think they're bad. Don't spend the money if the car warms up quickly and doesn't overheat.

ITALIANO66669

im a service tech so i dont need a dummy light.i can see if im loosing coolant and i have the dummy guage.also its good practice to check fluids when you fill up anyway instead of putting all of your trust in a coolant light.also a head gasket isnt that big of a mystery.