erratic temp guage

**finchy18** · June 30th, 2007 09:11 PM

I think its normal bro kpag traffic maging half temp sya at kpag long drive syempre baba ng 1/4. or kung hindi yan ganyan dati well its not normal.. check the radiator cap and aux fan..
sir what car model and year?

**4JGtootsie** · June 30th, 2007 09:17 PM

Check it pag 3/4 ang temp sisingaw yan somewhere.You will hear it.
Pag wala pa rin, its possible na sa cyl. gasket. Wag naman sana.
Do you have an overflow reserviour? May boiling ba doon?

**userfriendly** · June 30th, 2007 09:56 PM

Originally Posted by finchy18

I think its normal bro kpag traffic maging half temp sya at kpag long drive syempre baba ng 1/4. or kung hindi yan ganyan dati well its not normal.. check the radiator cap and aux fan..
sir what car model and year?

Chevy Venture 2002 model. Installed original rad cap last week of April. Before this, temp did not go up and down. Defective kaya yung new rad cap? O defective yung old cap kaya di gumagalaw yung reading?

Originally Posted by 4JGtootsie

Check it pag 3/4 ang temp sisingaw yan somewhere.You will hear it.
Pag wala pa rin, its possible na sa cyl. gasket. Wag naman sana.
Do you have an overflow reserviour? May boiling ba doon?

Wag naman sana. Pero aside from the coolant loss, I dont see the usual sins of defective cyl head gasket. No white colored smoke, no oil discoloration, no oil in the coolant, no power loss.

The time it almost reached 3/4, I was not able to check the reserviour. If there is boiling, what does it indicate?

What are the symptoms of a clogged radiator? I don't use the manufacturers recommended Dexcool coolant. Read too many horror stories of it turning into gel and cloging the rad. May effect kaya ito?

Also, I can borrow a laser thermometer from work. If I measure the entering coolant temp and leaving coolant temp, how big a temp difference should I be looking at? May use ba to?

**Yoda** · June 30th, 2007 10:03 PM

Is your thermostat working properly? Maybe it's stuck in the open position, or removed.

Kapag umaandar ka, water flows faster because the pump is driven faster. There's also a greater airflow through the radiator. If your thermostat is working, then it would regulate the water flow such that the engine operating temperature is maintained.

**4JGtootsie** · July 1st, 2007 10:10 AM

A loud boiling/gargling sound is a sign cyl head gasket failure. You can confirm it by the smell of exhaust fumes coming out of the reserviour.

**userfriendly** · July 1st, 2007 05:24 PM

Tried to troubleshoot. Car has not run for almost 2 days. Checked both upper and lower rad hose. No sign of damage and both dry. Checked reserviour, looks full. Removed the hose leading to the reserviour. Removed the rad cap, coolant spilled out. I noticed that with this car, whenever I remove the rad cap, coolant will spill out. What does this indicate? Overfilled kaya? Incidentally, the rad cap is at an angle. almost 45 degrees.

Started the car while looking at the exhuast pipe, no white smoke. Went to the back, no visible smoke at all. Just some water going out of the tail pipe. I belive this is normal.

Looked down the rad cap hole, coolant looks clear, no discoloration and no signs of oil contamination. Held the upper rad hose until I felt it warm up. Not long after coolant in rad hole went down a bit, looks like its circulating. No bubbles in coolant. (I belive bubbles is another sign of cyl gasket failure or air in the system) However, lower rad hose took longer to heat up.

Used an inexpensive hydrometer from Concorde. Result was good coolant, 225F boiling point protection. Not sure how accurate cause I was able to get the same reading with pure water.

Turned on the AC. Both fans turned on. Turned off AC, fan still running. Used my finger to touch a small part of the rad not covered by the fan, near rad hole. Area was hot. Did the same to the side of the upper rad hose. Also hot. Could not test the lower part for safety reasons.

Went to the back and smelled the exhuast. Smells normal, no smell of oil or coolant.

**4JGtootsie** · July 1st, 2007 11:01 PM

I think every thing is in order.
Two more questions. When was the last time you serviced/cleaned your radiator? Thorough flush?

**userfriendly** · July 2nd, 2007 07:46 AM

Di pa na service or flushed. I'm thinking that it might be dirty. At speed, the air flow is enough to keep it cool. At traffic, without the airflow, the temp goes up.

How do you check if a rad is dirty? I'll borrow the laser thermometer from work and if there are any cool spots then it is dirty. Is this correct?

The guage used to be relatively steady it will take time before it goes up or down. Now it reacts even with short distances.

**4JGtootsie** · July 2nd, 2007 10:13 AM

There is no sure way to know. Since never pa nalinis yan I guess it is time.
Since QC area ka naman yata. Sa tabi ng Ellens near Morato cor Timog may magaling na radiator shop.

**userfriendly** · July 2nd, 2007 05:32 PM

I'm thinking that it might be bec of:
1. stuck open or partially open thermostat
2. clogged or dirty radiator
3. fans are not spinning at correct speed

Which is most likely? And how can you tell if the fans is spinning at the correct speed? I see it spinning and can feel the air but have no idea how strong it should be. This car has 2 speed settings, low fan and high fan.

I also called 2 dealerships and explained the prob. The 1st said that as long as the guage does not go to 3/4 I'm ok. Normal lang daw. The 2nd dealer said bring it in cause it might lead to overheating. Sino kaya ang tama?