Greetings.
I'm having a strange problem with my 1995 Contour 2.0L I-4.
I'm getting intermittent CEL 172. My code scanner hasn't
arrived yet so all I can do currently is watch the CEL
indicator flash.
Brief History is in order.
2.0L I-4 unmodified 1995 Zetec, 109K miles.
Engine Temp got unusually high, to the end of L ("NORMAL")
Tested thermostat, it was seized closed so I replaced it
with Motorcraft standard (192 F).
Temp ran a little high but stable, at A(in "NORMAL").
Then I replaced O2 sensor but still no improvement,
problem still exists.
Finally put in a 180 F thermostat. I'm much happier with the
temp readings at R (in "NORMAL").
BUT ----------------
CEL still comes on intermittently, then goes off about
60 seconds later. Always seems to be code 172.
CEL mostly appears after driving highway speeds (60-70 MPH).
More wierdness, when CEL is on engine temp climbs a little,
then CEL goes out and temp goes back down.
Seems a little down on power but runs smoothly through
entire RPM range; Launch from dead stop is sluggish.
I think 172 means Lean mixture at O2 sensor.
Are there advantages/drawbacks to the 180 F thermostat
over the OEM 192 F?
HELP HELP HELP HELP. I am getting frustrated.
Some folks have suggested cleaning the UIM/LIM but I'm new
to this engine. Can you explain what/where these are?
Ditto for the IMRC.
EGR pressure sensor new 6000 miles ago.
How can I find/replace the PCV? Looks like it is in an
impossible place!! Any suggestions on trying to find a
vacuum leak? I've heard the "propane method" works pretty
well but is somewhat dangerous.
Is it time to take it to the (big bucks) shop or dealer?
Are there drawbacks to intermittent CEL 172?
Any Suggestions?
Regards -- This is a wonderful site.
Thanks to all that have helped me out in the past.
Gary J : Atlanta :
Post reply or send me private message.
