Contour Enthusiasts Group Archives Forums General Troubleshooting '95 Contour 2.0L - Overheating and CEL

Greetings;

I'm having some problems with higher than normal temps
in my 1995 Countour GL, 2.0L I-4, 109,000 miles.
It was running fine until last
week when the coolant temp got up near the red. So I took
out the thermostat and did boiled it. Sure enough, it did
NOT open, so I put in a new thermostat and O-ring (OEM
part from dealer because AZ and Advance replacements did
not look anything like the OEM).

Now it runs in the 'safe' temp zone (somewhere between the
M and A, as you look at the word NORMAL), but this is higher
than it was before the problem. Fan checks out, cuts on when
gauge gets to the 'A'). My concern is that it runs hotter
than usual. Could there be something else wrong? Water pump
is new OEM (6000 miles ago). Anybody ever hear of the
impeller breaking apart and reducing the flow?

When I replaced the coolant it seems I put in less than I
took out. Could there be an air pocket, and how do I get
the air out? Upper hose gets nice and hot, heater delivers
hot air so I guess flow is OK.

Also getting intermittent CEL. Best I can figure code is
172, related to O2 sensor. Any more details would be
appreciated. Could bad O2 sensor cause running hot? Should
I try to replace the O2 sensor. What size socket?

Finally, any thoughts on running without a thermostat,
or at least gut an old one. Manual says it is a bad idea
because the temp never gets up to where it should be.

Regards
Gary J. -- Atlanta.

First, an aftermarket 180 degree thermostat is great to have. www.zxtuner.com has one. H20 pump should be fine. If there is an air pocket, the system will get rid of it itself.
172 is a rich code. I can't see it really making the engine run hotter. Also it doesn't mean the o2 sensor is bad, but if you don't find what is causing it, it will eventually cause the o2 sensor to go bad. There is so many things it could be from, pcv system, intake leak, vacuum leak, etc. And always run with a thermostat...

Zetec engines are known to run hot, it's no big deal. Though using a 180 thermostat and a little more water than antifreeze (atleast in summer or warm locations) helps to keep it cool.

Don't panic because your guage reads something other that what you are anticipating it will read.

Your car may have had a lower temp thermostat in it or it may have been weak for a long time. Your new one sounds like it is correct.

If you are concerned with it, get a non-contact IR thermometer and actually measure the temperature at the water outlet. Normal operating rage will be up to 215F or so before the low speed fan kicks on.

Steve