heat problem

[userfriendly]

My car is experiencing high temp problems. Normal temp should be between 1/4 to 1/2 of the guage. Lately, it reaches around 5/8 or above 1/2. What I did the last 2 times the temp went up was to spray the radiator fins ( not top ) with water and the temp went back to normal.

Coolant is full and less than a year old, new radiator cap and new coolant sensor/thermoswitch. Both fans work. I think the thermostat works cause the upper radiator hose is hot.

Can this be due to a blocked radiator?

[gabs]

mine's a 96 honda civic. experiencing the same problem lately.
i discovered that the fan isn't turning anymore. although pinukpok nung mekaniko at okay na ulit, he said kailangan na ng new fan.

sabagay, logical nga naman kasi nag-ooverheat siya pag nakahinto yung kotse pero pag gumagalaw ng mabilisan, bumababa yung temperature kasi siguro dahil sa hangin.

Sana nakatulong!

[speedyfix]

you might want to replace the thermostat muna as the 1st option...

pukpok method on the fan doesn't last. replace it before you overheat again.

[mangdencio]

My car is experiencing high temp problems. Normal temp should be between 1/4 to 1/2 of the guage. Lately, it reaches around 5/8 or above 1/2. What I did the last 2 times the temp went up was to spray the radiator fins ( not top ) with water and the temp went back to normal.

Coolant is full and less than a year old, new radiator cap and new coolant sensor/thermoswitch. Both fans work. I think the thermostat works cause the upper radiator hose is hot.

Can this be due to a blocked radiator?

hi userfriendly!
pls.clarify if you have a higher than normal temp on the gauge or a real "overheating problem". Pls. take note that it's normal to register a higher temp.reading owing to the so called heat island effect aggravated by the summer season. In this case, no need to worry. The use of airconditioning during a hot day also puts an extra load to the engine, warming it up all the more. Overheating (pointer in the red marker) on the other hand, may be due to a lot of things: defective fan and/or auxiliary fan, defective thermostat, underspecs radiator cap, a blocked radiator, or a defective water pump. Based on your account, it looks like the radiator is the culprit. Cleaning the fins, you said, gave a temporay relief. The thermostat is definitely working as evidenced by a warm to touch upper hose. Unless you have a defective water pump that circulates cooled water through the engine, your radiator will be better off with reverse flushing...you can buy a radiator cleaning / flushing agent anywhere. Also, check if your fan still has a shroud on it as this definitely helps cool water passing through the fins..hope this helps.

[userfriendly]

pls.clarify if you have a higher than normal temp on the gauge or a real "overheating problem

The temp was higher than normal but still below the red zone. The red zone starts at 3/4 of the guage. My temp was a couple of notches below it.

Incidentally, the 2 times it went above normal April 20 and 23, it was during heavy traffic. When I was in SLEX, the temp was normal. When I hit traffic, the temp went up. Both times, ambient temp was very hot.

Not sure if this is related but my thermometer has erratic readings. When my engine temps were high, the thermometer was fluctuating between 38C to 43C. When I cooled the engine down with water, the thermometer read 28C.

I just drove the car today for close to 3 hours. Lipa to Manila with heavy traffic. Engine temp maxed out at just a hair above 1/2. Light rain.

is it possible that the hot summer we are having is making my car run hotter than normal? Is my car fine or do I have to have it checked for a blocked radiator?

[userfriendly]

Add ko lang. Yung engine temp guage ay malaro, up and down by a few degrees. And when my driver changed the radiator cap, the coolant overflowed.

What do you guys think?

Update lang, had the car's radiator pressure tested, no leaks. Mechanic inserted a temp probe in the radiator, coolant temp was at 220F and the fans were not yet turning, AC off. Engine temp went 2 notches above 1/2 before the 2 fans turned on, AC off. Turned on the AC both fans ran and temp guage went to below 1/2.

He said there is no blockage in the radiator as the temp should not normalize if its blocked. Tama ba? He is thinking that the new thremoswitch's setting is too high. Over 1/2 before fans kick in when AC is off. He also wants to replace the thermostat. Opinons please.

[mbeige]

What temperature does the thermoswitch open? It should be indicated/etched on the side or something. That way you know what to expect when the coolant temp reaches that temp (fans should start).

Agree on replacing thermostat. Get one that's set lower than factory. If it says it opens at a certain temperature, it means it just starts to open at that temperature, but the operating temperature of the car will be higher since the thermostat is only rated to open at that temp. It will be fully open a few degrees higher.

[userfriendly]

Don't know what its settings are. I got an original thermoswitch and assumed that its the same as the factory setting.

[mangdencio]

What temperature does the thermoswitch open? It should be indicated/etched on the side or something. That way you know what to expect when the coolant temp reaches that temp (fans should start).

Agree on replacing thermostat. Get one that's set lower than factory. If it says it opens at a certain temperature, it means it just starts to open at that temperature, but the operating temperature of the car will be higher since the thermostat is only rated to open at that temp. It will be fully open a few degrees higher.

removal and checking the thermostat is fairly easy.
1. remove the upper radiator hose
2. unscrew the two or three bolts of the thermostat housing, noting the gasket and / or mounting position.
3. visually inspect the thermostat for corrosion (rust), cracked or broken coil. perform a test on the thermostat.you'll need to submerge the thermostat fully in a pot. have a thermometer ready to take the temp. reading.
4. bring water to desired temperature (i.e. thermostat working temperature etched on its top) and observe if the thermostat opens. take note at what temperature it opened then compare it to specs. replace, if it opened way too late or too far up the thermometer or if it didn't open at all.
5. re - install the new or re-conditioned thermostat, housing, bolts and hoses.

i recommend against replacing the original thermostat (oem) with a lower rating. the thermostat is designed to open at a certain water/coolant temperature. this condition happens when the engine has achieved its operating temperature. the job of the thermostat is to allow the engine to warm up quickly (for optimum performance) during start up and maintain its operating temperature by opening (if it gets too hot) and closing (if it falls below operating temp.) this has been pre-determined by OEM and pretty much established by the car manufacturer's specs.
the idea of having a low rated thermostat is to let the engine operate at a slightly cooler operating temperature since heat (summer season) definitely affects engine temp. via radiative/convective/conductive heating.
however, to offset this dilemma, you can perform a lot of adjunctive means to avoid overheating other than picking on the thermostat (unless it needs replacement) : the main thing is regular maintenance (engine flushing and radiator flushing recommended), strict compliance with coolant application, regular oil change and tune up, etc..
modifying the engine bay helps. does your hood already have thermal insulation (you know that aluminum or aluminized sheath with polymeric padding- white) underneath it?insulating the cowl and the firewall helps as well.

[mbeige]

^^ Mangdencio has a good point but I forgot to write something. Only do the lower setting thermostat in the summer when it's really hot. That way the extra margin allows for the ambient heat to further quicken the warm up process.