MM overheated

[Murader03]

I had noticed over the course of several days, that it was taking longer and longer to get heat in the cabin. No matter where I set the controls, temp, fan, or position, heat just wasn't to be. The "Temp" gauge was reading normally throughout the period, up until Tuesday morning on my way "home" from work. As I got to highway speeds, the temp gauge started to climb. So, I stopped after I got through the toll gate. MM had plenty of coolant, but noticed some fluid around the top. Got back in the car, gauge was reading normally again. Started off, and it climbed again. Got off at the next exit hoping to be able to limp to my local FMC dealer. "NOT!" Gauge really started to climb and into the red zone it went. As I pulled over just as the engine started pinging like carzy. :(:cry:

Called for a tow truck to get me to the dealer. I suspected the thermostat had stuck closed, as there was absolutely no water flowing through the hoses as I could collapse them with my hands, no pressure. After putting the scanner on the car, and a few other tests that took over an hour, they concluded the thermostat was bad. Gee, isn't thsat what I said? Anyway, after waiting another 2 hours for them to get a thermostat, I was on my way.

So far, no further problems! First time I've ever had to be towed to a dealer since back in the early 90's when I owned a CV with the HPP mods. Thanks AAA and the extended warranty I bought. :bows:

[TripleTransAm]

Is this the stock thermostat or an aftermarket unit?

[Haggis]

Glad to hear all is ok with your car Bob. You definitely missed the bullet that time. As Steve asks was it the OEM thermostat?

[Murader03]

Guys: Sorry, it was the OEM thermostat with 46.5K on the clock. Never got around to installing the stat that came from Dennis. Anyway, I see there was another MM the overheated in a thread that was posted on 2/12. He didn't say if his was the OEM or not, but it might be an item to start watching. He had less than 6K on the car. The other thread was posted by Agent M79 on 2/11 "Uh Oh!"

[TAF]

Bob,

Agent (Dave) actually had Dennis' 180 degree 'stat in...BUT his was not the 'stat but a radiator hose which came loose at the clamp. The wrench told him it looked like it came loose like that from "day 1 at the factory".

Glad to hear you caught yours in time, as well.:up:

[Saleengene]

I seem to remember reading somewhere in the Mercury literature that the engine will go into a limp mode when it senses overheating. The engine is supposed to cut out the ignition to 4 cylinders. By drawing air and fuel into these cylinders and not igniting the mix, a cooling effect on the engine is produced. I would imagine it would run like crap but at least you could limp to an area where it would be safe to get off the highway.

Gene

[Agent M79]

I did not let it get into the red. Got close, but not quite. No pinging or knocking to report. That would have made me brown the leather.

I do have the 180 degree stat but that was not the problem. The lower radiator hose "came off" and the tech said the clamp was likely bad from the factory and was shocked it took so long to become apparent.

Good as new now. Took it the long way home tonight, over drive off, foot down for a good 20 minutes and the temp stayed at (TAF...) 18MPH.

[Murader03]

I seem to remember reading somewhere in the Mercury literature that the engine will go into a limp mode when it senses overheating. The engine is supposed to cut out the ignition to 4 cylinders. By drawing air and fuel into these cylinders and not igniting the mix, a cooling effect on the engine is produced. I would imagine it would run like crap but at least you could limp to an area where it would be safe to get off the highway.

Gene
I don't think it ever got to the limp mode, of there is one, and if that was it when it started pinging, then it'll never get that far again. I was already off the limited access highway and running up the local 4-lane to get to the dealer when gauge went almost to the red before I stopped. I was on the left shoulder, let it cool down and as soon as traffic allowed moved to the right shoulder. From there it was a roolback to the dealer for repair.