Hi all, kinda new to this forum. Hope someone can help.

Noticed today that my 93 (M/T) Accord LX's temp gauge climbs up to the red level - and here's the clincher - when the engine is on idle. I drive about 40mi to and from work each way, and noticed the gauge alarmingly high while at a stoplight. On the highway, at cruising speed, the gauge goes to normal levels. First I thought it was lacking coolant, so I went and bought some Prestone A/F and filled up the reservoir. Didn't help. Noticed that the gauge would start coming down when the rev is at 1500rpm or so - tried revving at a stop (at neutral) to see where the needle would start to drop.

Is it a bad temp gauge? Thermostat? Something more expensive? TIA for the help. Cheers.

 

no it sounds like you really are overheating. maybe a fan is out. make sure the actual radiator is full of coolant not just the reservior

 

Thanks for the reply.

I forgot to mention - when I filled the reservoir w/ coolant, I touched the rad cap and it didn't feel like it was overheating. Warm, but not too hot, to the touch. It's a relatively new rad - replaced it this century - but I don't know how to tell visually if it is indeed overheating. Any telltale signs I could look for? Can I open the cap and pour coolant directly into the rad?

Also, the fan comes on as expected.

Thanks again.

 

Yes you can. In fact, there's a couple situations where the reservoir will be full while the radiator isn't full. So it would be a real good idea to check to make sure it's full. Also you need to bleed all the air out of the cooling system. There's probably a bleed screw in the thermostat housing for bleeding out air bubbles.

When you squeeze the radiator hoses you shouldn't hear sloshing noises, that would indicate air in the system.

 

First off, make sure radiator is full ,, if not pressure test system and chk for leaks if any leaks repair as needed..make sure to bleed thje system,, also teast the radiator cap

if rad is ok, no leaks,, start the car and let engine warm up,, when warm the LOWER radiator hose should feel HOT to the touch ,, if it feels LUKEWARM or COOL the thermostat is stuck closed ......replace as needed

if t-stat opens ok, let engine warm up more ,, make sure that BOTH fans will come on ,
if only 1 fan comes on we need to diagnose why

if NO FAN come on,, on the thermostat housing there is a plug, 2 wires going to it . it is the cooling fan sensor,, unplug it, jump the 2 wires together use a paper clip, if fans come on you got a bad switch replace as needed

if they DO NOT come on we need to diagnose,,,,,,,,, chk fuses first

try this and let us know

 

If the lower hose is cool after the engine warms up, there's another possibility: a blocked radiator. With an obstructed radiator core, the flow rate thru the radiator is too slow. The water spends plenty of time IN the radiator & cools off a lot, but the flow is so low it can't cool the engine.