Temp Gauge Was In The Red Today...Just Changed ECTS

[BassHypnotist]

Over the weekend I changed the spark plugs and the ECTS which had already been changed prior to me buying it, but I didn't know until I pulled it out and figured I might as well change it since it was cheap. Today while sitting for 5 - 10 minutes with the air conditioner on I realized the temp gauge was in the red. It is the first time I've sat for that long with the A/C on so I don't know if the issue was there prior to me changing the ECTS. I turned the A/C off and put the heat on and the temp came down in a couple minutes. The gauge is usually at the 3/8ths mark during normal driving, both before and after the ECTS change. The coolant level in the reservoir was just below the low mark which is obviously low but not crazy low so I don't think that was the issue. I am constantly refilling it which is another issue although possibly connected. It isn't leaking fluid but still goes through a quart of water/anti-freeze every week or so. It has about 94,000 miles on it of which I've only put on about 12k. Not sure if the thermostat was changed prior to me getting it.

Your thoughts? Thanks for your help.

[fdryer]

You may have more than one issue; possibly a worn out cooling fan, thermostat and either a radiator or water pump leak. Losing coolant either leaks out or is getting by a blown head gasket. The transmission cooler fittings are a likely point of worn radiators leaking coolant. The other is the water pump otherwise its loose hose clamps or old hoses cracking from bulging.

The cooling fan runs at one speed and should be running strong, not wimpy. A sign of a worn out fan is if it runs less than loud. If your a/c works then the fan should run at the same time. Check to be sure it runs and runs strong. A weak or worn out fan won't blow with sufficient force to cool off the hot condenser coil and radiator, letting the coolant over heat. Usually when the a/c runs the coolant temp drops since the fan is needed to blow through two sets of coils.

[Signmaster]

First and easiest test is the fan. If movement above approx 10-15 mph brings the temp back down then the radiator is not too clogged and the thermostat is open. If you let the car get hot again and the cooling fan won't cool it down, it's likely gone. The fan should come on any time the AC is on.

[madpogue]

Originally Posted by BassHypnotist

It isn't leaking fluid but still goes through a quart of water/anti-freeze every week or so.

It's leaking. Or it's boiling out, which is another form of leak. Make sure the mix is AT LEAST 50% anti-freeze, up to 60% is better. If you still lose coolant, replace the reservoir cap. Also consider a cold pressure test, to see if there's a marginal leak somewhere, esp. the left radiator tank.

Was the cooling fan running while you had the A/C on?

[SC2Sick]

Check your thermostat / water pump. I had mine leaking and couldn't figure out where it was leaking from for the longest time (the first time.. not the dozens of other times on other cars).

[brags]

keep an eye on the temp gauge saturns are not forgiving if overheated they
will damage the head gasket.. in no time.!

[BassHypnotist]

You guys called it right. Checked the fan when the A/C was on and it wasn't running. I replaced the radiator a few months ago because the top water line was leaking at the housing. While I could have messed something up, or left something unplugged, I don't think I did. I checked the fuses under the hood and they were good. The connector looks plugged in and clean but I will check it again tomorrow when the engine is cool. Is there somewhere or something else I should check before assuming the fan itself is dead?

As for the coolant disappearing, I have never found a leak or seen fluid under the car. Is it possible that it is leaking/evaporating in a way that doesn't leave a trace? I just assumed it was an issue with the head or something and it was getting sucked into the pistons.

[adventureoflink]

There is always hot wiring the fan to run through the battery.. there's a video in the new/returning S-series owners' checklist that covers this..

Also, this is why you replace the reservior cap.

[fdryer]

Check the fan fuse, fan relay, then the fan connector. Carefully spin the fan by hand. Sometimes, corrosion prevents a good electrical connection and 'exercising' the connection by disconnecting/connecting scrapes away corrosion for better electrical conduction. If the fan still won't turn on with the a/c turned on then try wiring the fan directly to the battery; if the fan won't run or runs slowly, replace it.

With a dead fan not running when needed, the cooling system may have overheated and vents out the coolant cap as it automatically relieves pressures above (approximately) 18psi. Once the fan issue is fixed, monitor the coolant level; if no more coolant is lost then it was the dead fan causing the coolant to overflow out the pressure cap vent.

[madpogue]

Quickest test - disconnect the fan, put a voltmeter on the connector of the harnes, start the engine, turn on the A/C. If you get voltage, everything up to that point is good and it's new fan motor time. If not, you get to start looking "upstream" (wiring, fuse, relay, PCM trigger, etc).

[alordofchaos]

Originally Posted by BassHypnotist

As for the coolant disappearing, I have never found a leak or seen fluid under the car. Is it possible that it is leaking/evaporating in a way that doesn't leave a trace?

system is pretty well sealed - I don't think anyone lost coolant in the first 5 years when the cars were new. As mentioned, could be boiling out. Did you look around the water pump? I've no experience with this myself but have read about a seal that will weep small amounts of coolant there

[Bernie]

After replacing my thermostat there was a very tiny leak whose source was impossible to determine accurately. It that was either at the thermostat housing seal or hose clamp. The O-ring that came with the Stant thermostat looked awfully thin and fit very loosely within the housing groove. I torqued the mounting bolts and the hose clamp a bit more and everything sealed. But, like I said, it was impossible to know where it was leaking from, though I suspected the O-ring and hose clamp.