REVscene - Vancouver Automotive Forum

Van-Isle · 10-25-2010, 05:51 PM

hey all, Long story, but hopefully somebody'll read it all thru and help me out..

95 b18b1 LS, 230ks..

heater this morning was really cold, temp guage on dash was also dancing up and down, then started going towards hot. pulled into a parking lot and shut er down, and checked the hoses,Top rad hose was hot, while lower was cold.

the suction tube on the lid of the overflow bottle had fallen into the tank, so the rad filled it up when it started getting hot, and couldnt draw it back into the rad. I filled the rad with all of the coolant from the overflow and limped her home.
bought a new thermostat and installed it.

I burped the cooling system and went for a drive. Sitting idling at traffic lights the temp sits where it always did, but as soon as i start driving the temp on the guage lowers significantly. I've also never seen either of the fans turn on.

where can i start looking into this? I want to make sure my temp gauge is working correctly so i can keep an eye on the situation.

Thanks,

\trevor

Van-Isle · 10-25-2010, 08:36 PM

My gas mileage has seemed to take a major turn for the worst? Is it because car thinks it's cold so it runs pig rich? Temp gauge reads cold as soon as i start moving, car can have sat idling for 20 mins and be fully warmed, and start moving, Temp gauge dives..

What gives?

Van-Isle · 10-26-2010, 02:14 PM

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Rad looks brand new, has fresh coolant in it, I just got the car, so not sure on mileage on the waterpump, But i dont think it's the issue.

Found out the fans do work, I had only assumed they were supposed to run constantly.

my next question is what is causing the temp gauge to drop to zero once the car is in motion? I replaced all of the lost coolant with 50/50 coolant and water.

Thermostat can only fit in the car one way correct? I just want my gauge to work so i can make sure i dont blow a head gasket.

Trevor

lexluthor09 · 10-26-2010, 06:30 PM

sounds more than anything like you're running cold so i dont think you need to worry about blowing that head gasket.

is your heater on? are you noticing all this when you warm up the car? do you get hot air?
have you tried testing the sensor? eg. testing with an ohmeter either piggy backing it, or disconnect the sensor and short itself or short to ground (one goes to super cold one goes to super hot)

all the things you've corrected would make the car overheat, but you're experiencing the complete opposite

Van-Isle · 10-27-2010, 05:53 AM

The car heats up fine, and blows air just as hot as previously. The odd thing was, Last night i took it for a drive for quite a while, kept checking the overflow, then parked at a friends house for long enough for it to cool, and then drove it again.

The overflow dropped a considerable amount, so i topped it up a bit,and drove it some more. The gauge seems fine now..

Cold it have been just a large pocket of air I couldnt get out when burping the cooling system? The bleed nipple on the top rad hose where it goes into the block was stripped from a previous person i guess.

Tapioca · 10-27-2010, 08:13 AM

If the car is in motion and the temperature gauge drops, it is usually your thermostat because it's staying open. However, you've replaced your thermostat so unless it's a defective part (i.e. it's staying open), you probably just need to bleed the system again.

There is another smaller hose which carries coolant on the B-series engines. Make sure this clamped on tight and free of holes.

Van-Isle · 10-27-2010, 02:45 PM

I belive it was just a large air pocket, Drove to and from work today, All is working. Thanks

fliptuner · 10-28-2010, 09:37 AM

For future reference.

When bleeding the system, it's better if the front of the car is slightly raised to facilitate the air coming out of the rad. Fill the rad with the car running and the overflow tank full. Leave the engine running with the rad cap off, blower fan on low, temp on hot and defrost. Let the air work itself out and replace fluid as needed until the rad fan turns on (this may take awhile). Replace the cap, crack the bleeder valve til no bubles come out and top up the overflow. Done.

Van-Isle · 10-29-2010, 12:47 PM

Thought it had fixed itsself, turns out the thermostat was faulty, and would stay open, over cooling it. Replaced it, this thermostat came with a gasket, and bled it following fliptuners method. All is well again. Thanks!