disheeki546

My girlfriends Taurus overheated a while back due to it running out of coolant recently and developed a bad misfire and shake mostly under 2k rpm. The coolant drained because of a clamp not being put back on the end of the upper rad hose and it came off. I was in the car when it happened, the coolant gauge didn't show it overheating, I am guessing because there was no coolant surrounding the temp sensor. Anyways, I got it cooled down and refilled and we went on, but it had a bad shake. I checked it out and there is no smoke, no loss of oil or coolant, but the plugs were pretty black and overheated because there was a blueish ring around them. I changed them and it solved the majority of the shake and misfire but there is still a bit left. Enough to still trigger the check engine light.
It's a 2002 Ford Taurus with the 3.0 ohv Vulcan engine. My question is simply what else should I be looking at? Any model/engine specific things? I need to get her off my back about this damn car.
Thanks, Mike.

disheeki546

bump

The Guy

Well, the first thing i thought of was the ol' head gasket, but it seems to have been ruled out. Check and see what code it is.

91se-r

What code is the PCM setting? P0300 ramdom misfire or a specific cylinder? Do you know anyone with a good scan tool that can do a power balance or a relative compression test? That's where I would start. There are quite a number of bad things that can happen when you run one hot without coolant in the system.

disheeki546

i got the codes at home, ill post in a few hours. it was random misfire and under 1k rpm. no i dont know anyone with a scan tool. I just went to autozone and scanned it there.

98formulaLS1

I don't know if there's any data to support this claim BUT if the plugs were badly damaged, there might be a possibility that the high voltages used to create the spark might not have been as well transferred to the spark plug, thus damaging the coil pack. I had a coil pack problem on my Vulcan a little while back too. They are super quick to replace, and if it doesn't solve the problem, return them. You'll be able to installed and uninstall it without making any marks on it.

disheeki546

/\ i was thinking that. it really did and still does feel like a spark problem, but i know the plugs are new, clean and gapped. ill let you know how it works out if/when i try it.

91se-r

It could be a spark problem but if it's a random misfire I would also be looking at the camshaft synchronizer and CMP sensor. We have had known issues with them being noisy due to the internal bushing wearing out and with the magnet in the sensor coming loose.

disheeki546

/\ but would that come up all of the sudden due to overheating?

The Guy

Well, just like everything else, it is POSSIBLE due to the extreme heat that the engine put out.