wack temp gauge January 29, 2006, 03:43:26 PM help help I have a 88 merc. cougar 3.8 fuel injected. nice car but I have had a naging problem drive highway or city the temp gauge goes from o in norm to h from time to time it only sit ther for a minute to 3 minute while driving then goes back to o. now the funny thing is I got to the house and it was raising to h so I let it run it got to the h mark so I shut it off and then turn the key back on and it was between the o and the r. if it was a true coolant problem the temp shou have gone up right after I shut it of not down.I have replaced the water pump the thermastate with a 192,180,160 and it makes no difference except for the running temp o =160 r=180 and r to m for 192 stat. I replace the engine sensor twice with no difference. I check the pump cap. and flushed the radator it clear and free flowing the air dam is there.so whats the deal it has 183,000 miles on it no oil burning what so ever.Can I put a aftermarket gauge in it to test to see if it the wireing or does the computer use the anloge gauge reading in some way.If it was truly runng hot I would think I would hear knoking pinging or something of a hot smell.Now when it did it before sometimes the heater would blow cold until the temp whent down off of hot but that would mean a air lock but the coolant is full.ok is there any help here or should I trade it in on a another used car??????Edit/Delete Message Quote Selected