Temperature gauge anomaly

Page may contain affiliate links. Please see terms for details.


Sep 3, 2023
Jeep patriot 2.1 om651
So, don't shoot me down if this is simply quite normal .. I cant say I've noticed it before in any of my motors but for some reason when I go down a large hill .. like on a motorway or dual carriageway my temperature gauge drops from approx 88/90 degrees down to 75/80 degrees .. so approximately drops 10 degrees quite quickly, id say within 15 seconds of driving down the said hill in question. Is that normal?
All of mine have always reached temp & stayed there regardless. Have you checked the levels?
The OM651 has a mapped thermostat meaning the thermostat operates depending on engine load, ambient temp, engine speed etc.

Mine fluctuates between 80 and 90C. If say I drive 100miles of motorway the temp often stays around 90, once off and onto a a or B road the temp will drop sometimes as low as 80C for a while and then return to 90C depending on road conditions.

If I drive steadily for a while the temp stays rock solid, if I give a sudden burst of acceleration the temp will drop. its something to do with efficiency of cooling etc and perfectly normal.

Its a very clever system and helps with MPG and efficient running.. Its not faulty and its not a failed thermostat.

Mines been this way for the last 5 years.
^^^^That's progress for you

Users who are viewing this thread

Top Bottom