Ok, to those of you more mechanically inclined than I, I ask for your opinion in helping to solve this small problem I have at the moment.

I have an 87 Prelude Si. The problem is basically this, it will overheat in traffic after about 20 minutes of sitting still. When I am driving on the highway it is fine and runs very cool, but after 8 or 9 minutes sitting still the gauge will climb to half way and after that I can start smelling the coolant. Also, sometimes, the idle rpm is bouncing up and down, from about 500 to 1700 rpms, when I come to a stop. I believe these have a connection, but I'm not sure.

I changed the water pump and checked the belts, but that didn't solve the problem as that was my first impression. I also changed the thermostat too. I've flushed the radiator as well.

What do you think could be the problem?

Thank you very much for any help.

 

do you have a check engine light? get an oil change, check everything and then come back. is there any smoke coming out of your exhuast?

 

no check engine light, and i just changed the oil 1k miles ago, no smoke either.(i check regularly)

 

change out your thermostat.... ez fix. over heating is duel to improper cooling. which is your water pump or thermostat... so, since you did your water pump... its gotta be your thermostat. costs about 15 bucks at pep boys. buy that and a tube or sealant and a gasket. takes roughly about 30 minutes to replace.

 

also make sure your fans are working... this would explain the cooling while moving but the not while still

 

thats true i missed that one. so... fans and thermostat. do what i said for the thermostat. the fans are also easy. just turn on the car and stand infront and watch the fans... if they come on, then they work. if they dont then find out why. you can always just wire the fans to a switch and run them all the time, it doesnt really hurt much.

****if you run your heater on full blast, it might slow down the overheating****

 

I have a 97 lude and my rpms bounce like yours from about 500 to 1700, It only happens when my AC is on and its hot as **** outside, but I live in Florida so I figure its going to happen no matter what. Should I also Inspect my cooling system for this (minor?) problem?

 

Also, be sure that there are no air bubbles in the cooling system when you fill it back up! That's always common with my CRVTEC. Using the bleeder screw is key! HTH

Dan P.

 

if the thermostat dosent fix it try the coolant temp sensor. $7 or so. that fixed mine.