I searched this forum under "low coolant" and couldn't find my problem. My 85 GSL-SE is using coolant. Has 120,000 miles on it, no other issues. Coolant level is fine for a couple of weeks and then it's suddenly down 1/2 gallon. This happens about every 2 tanks of gasoline. Seems to be getting worse. It was down after one tank this week. The car runs fine and doesn't overheat. Try as I might, I can't find any leaks anywhere. Also it doesn't smoke. Maybe a small puff when starting, but no more than my other SE or my FD. One other thing: it was hard to start this week after sitting all night and flooded for the first time in 2 years since I've had the car. It spun over fine and then "bucked" a couple of times before it flooded. Started fine this morning. I know the coolant is going somewhere but with no leaks and no smoke, I'm stumped. Any help appreciated.

 

no leaks. replace your radiator cap.

 

Thanks. Will do. I guess it could be pushing coolant into the resovoir and out the overflow tube while I'm driving, and there would be no leaks under the car after the car was parked.

 

Check your passenger foot well and see if it is moist, that will be a leaking heater core.

When mine mysteriously lost coolant, it turned out that it was pouring out when the car went WOT, I was showing a few friends the car after I got her done, and when I revved it up, the outboard side of the heater core would spray coolant out from a loose fitting. Mine leaked from the engine side of the firewall.

Check your intake manifold, the O rings may be leaking. It won't be a huge leak if you are not smoking, but maybe a few drops here and there. Those add up.

Like wacky said, check/change your coolant cap. And tighten all fittings!

 

My last 2 SE's had the same problem. i pulled the passenger side carpet and it was wet. if you dont mind not having heat you can bypass the heater core.

no lower intake orings but there are 2 hoses that are on the upper intake mani for the cold start assist(if you havent chaged those 2 hoses yet please do so i lost and engine to one springing a leak and over heating)

 

I replaced the radiator cap, although the old one showed no deterioation of the rubber and the spring felt strong and it looked new(maybe replaced a couple of years ago by the previous owner). I'm taking a road trip tomorrow, so I'll report the results this weekend.

I don't think it's the heater core because there's no coolant smell in the car nor any wetness on the floor, and I've had the heater valve closed all summer.

I snugged up all the water/heater hoses.

There is one hose (I think it's the mandifold heater hose that 3rd and Final 7 referred to) that comes out of a valve on the mandifold and returns to the rear of the block, and it's hard to see where it fits into the block. There is a possibility that it's leaking there although I've never seen a drop of water under the car, and I've watched it closely for a month. The hose entering that valve comes off of the water pump housing so I think it's one of the pair that he referred to. The valve is on the rear passenger side of the engine near the firewall and is underneath the brackets that hold the cruise control and throttle cables to the engine. I'll take my flashlight and watch that hose nipple this week.

Thanks for all the suggustions, guys.