QuestionI am currently experiencing intermittant rough idle and sometimes rough acceleration. I am currently running without a thermostat. Any relation? Engine is a 2.5L v6 with 190k miles
AnswerHi Fran,
That is a relevant observation in re the vent hole/flapper valve. My manual for that time era show there to be such a hole/valve so my inclination would be to try a Chrysler dealer for a factory part. It is related to the need to have some modest flow-thru inorder to get air out of the system, to the best of my knowledge, or perhaps to establish some flow for heater operation during warm-up. In any case, it should be "up" when you install it. Worse comes to worse you can drill a hole.
Roland
Hi Fran,
If the engine doesn't reach normal operating temperature because of the lack of a thermostat then the engine controller will not bring into play its full panoply of sensors that optimize performance and economy. So I would put in the proper thermostat and access the situation. Why was the thermostat removed? Running too hot? Then address that issue.
You might also do well to check for any fault codes that the controller may have recognized (in addition to the delayed warm up issue). Take the ignition key and turn it:"on-off-on-off-on and leave it
on" doing that in an elapsed time of 5 seconds or less. I mean by
'on' just to the place where the key sits when the engine is
running and you are going down the road.
Then watch the 'check engine' light which remains 'on' when the
key is in the run position but the engine isn't running. Soon it
will start to flash, pause, flash, pause, etc. Count the number of
flashes before each pause and keep track of those. Then do the
key trick again to repeat the process and thus verify that you
have the numbers accurately. Then group the numbers in pairs
in the order that they occured to form two digit numbers which
are the fault codes. The last such number will be 55 which is the
code for "end of readout".
You can erase the present stored codes by disconnecting the battery for a few minutes. Then after you replace the thermostat and drive for a few trips repeat the readout for a fresh look at the situation post-thermostat replacement. You will find a new code 12 as the result of disconnecting the battery. Then either write me back and tell me
the numbers for further advice and/or go to
www.allpar.com/fix/codes.html where you can find a list of what
the codes mean. When you write back tell me which engine you
have, if it isn't the 2.5 V-6 and also tell me if the car originally
was delivered in California or Canada so I know how its pollution
equipment is set up. If I am shown as maxed out just use the "thank and rate" tab
below and there is an opportunity there to respond via the
comment section.
