Severin

It's been 97->100 degrees this week, phew
Driving around town, my temp gauge will rise to more than 3/4 of the way to HOT (normally it's a tad below half) and continue to fluctuate between normal and hot.
I noticed this last year during some really hot weather, and when I had the timing belt replaced I also had them replace the thermostat.
Needless to say, I still see the needle spike up.

Both cooling fans are running (a/c is on); I don't believe I have any air bubbles either.

Other than the radiator being 14 years old, any other ideas?

RONE

Have you blown out your radiator to remove rocks, bugs, rubbers, etc? What percent of the fins are bent over/damaged? Is your coolant full?

cleptosis

iTrader: (1)

need a new thermostat before it dies i would go for mishimoto they are 58 and stay 10-c cooler

Severin

The thermostat is a year old; I had the same temperature spikes on >98 degree days with the old thermostat, so I think I can rule the thermostat out.

The radiator fins below the bumper are pretty smashed from 14 years of road debris; I suppose I could try combing them out.
I'll pop the radiator cap tomorrow, but the reservoir is at the correct level.
I know the cooling system was bled when the thermostat was replaced last year. Since the overheating occurred before that as well, I find it hard to believe I'd have another air pocket again.

3.2TLc

Yeah, try cleaning the rad's fins. Was a Honda 2 stage T-stat installed ? Our cars like them better than the generic aftermarket brands. Have the cooling system pressure checked. Make sure that you have the correct ratio of coolant to water. Look inside the rad for any residual build up which may restrict the coolant's flow.

Make sure that the cooling fan is operational, could be a bad thermosensor.

RC99TL

It's the radiator/condenser not flowing air due to debris and bent fins.
I just posted this issue last week. Seems like our cars are coming up to a radiator service point! I hosed out the radiator and then spent about 30 minutes carefully opening up the bent up areas. Huge difference. In 104º temps the temp gauge never went past half and the A/C blows colder than ever. Everyone should take a look.

Walfunk

Was having the same exact issue...was just low on coolant, about 1 1/2 quart...no signs of leaks or anything? WTF? Check the garage floor and coolant level everyday but good so far. How could this be? Where did the coolant go? Changed the oil yesterday and the oil was good as well...

3.2TLc

Have the cooling system pressure checked. May have a pinhole leak somewhere that only will leak under running temp. Sometimes they are difficult to locate. Could also be blowing by the head gasket through the exhaust.

Walfunk

Checking fluid everyday...same level, so I dunno....no sign of leakage....strange

RONE

Having you straightened the radiator fins?