...4 cyl automatic trans (lx 4 door)

I just got done changing timing belt water pump plugs wires hoses thermostat etc.... took it to a good mechanic and had him adjust the valve lash.

Car ran fine for two days.....150 miles...city and highway......then on the way home from work driving at highway speed I look down and the temperature gage is pegged Hot, I pull over and look under hood and can't see any problems, on the way home the temperature comes down and every once in a while bounces around (seems to rapid to actually be the engine temp bouncing like that but.......maybe??)
Where is the temperature sending probe? I pulled the connectors on what I thought might be the temp sending unit (two in the vicinity of the thermostat) but with connector pullled I was still getting a temp reading on the gage so I figure it's not either of them..... Where is the sensor for the temp gage in the dash?
Drove the car some more after it cooled off, seems like it took a little long for the temp to come up, then it keeps going up then suddenly drops to near normal then seems to fluctuate up and down as I am driving....sticking thermostat or bad sensor or bad sensor wire/connection?

Any help greatly appreciated.

 

my 98 does this too. Do you have any problems with your speedometer not working? most of the time when mine happens the speedometer doesnt work either. The car also lacks power and idles rough at the same time...

 

It may be some air pockets trapped in the cooling system. Try to purge the air out of the system.

In regards to the temp sensor for the gauge, for your car I believe it is under the distributor. Refer to image.

 

redbull-1.....thank you for the picture. How do I bleed the air out of the coolant system?

The car seems to do ok until I get on the highway, then it goes way up and then jumps down to near nprmal, then bounce around.....get off the high way to a 35mph road and it reverts to normal operating temperature. Could it be a sticky thermostat (it is new out of the box...)?!?

I'll be checking the temp sensor too...

Thanks

P.S. (to bozos_si) No problems with speedometer...

 

Part #12 in that picture is a bleed valve. When the engine is cold, loosen it to let the air out. Then top up the antifreeze at the radiator cap.

 

To purge the air out of the cooling system:

1. Turn the heater control to max heat.
2. Remove the radiator cap.
3. Some Accords have an air bleed bolt near the thermostat housing, where you would loosen the air bleed bolt, then fill the radiator with a 50/50 coolant mix to the radiator neck. Tighten the bleed bolt as soon as coolant comes out in a steady stream without bubbles. But, this is not always necessary and sometimes ineffective. (This step can be skipped or may not be applicable to your car.)
4. If you want, you can jack up the front of the car which will help to get the air out easier. But, not necessary. (This step can be skipped.)
5. With the radiator cap off, start the engine and run it till it is at operating temperature. Add coolant as necessary. This may take a while, I usually run it until I see no more bubbles or air coming from the radiator for a while.

I usually rev the car up a little while the car is warming up to help get the air out and to open the thermostat faster, and refill as necessary along the way. Later, I will also feel the lower radiator hose to make sure the coolant is warm which tells me the thermostat has opened. (But, be careful of the fans, belts, etc.).

 

OK,
Today I replaced the thermostat (again). Filled the system cold and used the bleed valve. Ran the vehicle for a bith with the radiator cap off and kept filling till no more bubbles then put cap on. Ran up to temperature with heater on. Shut off engine and cracked bleed valve again with system hot.
Drove the car 4-5 miles down the highway and then 4-5 miles back. With system hot and under pressure I momentarily cracked open the bleed valve again.
Ran 30 miles at 74 or so mph. Temperature gage is steady and in the correct range now. Will be watching closely for the next few days as I put some miles on it.
Thank you much for the help (diagram pointing out the appropriate parts was essential)!!!!