My SW-2 cooling systems troubles, need advice...?
 

1998 Saturn Wagon 2

For the last few months my car cooling system seems to be running hotter than normal per the dash gauge. For years and even the the summer the temp gauge would never get over 1/4. I need to add coolant to it now weekly but there is no leak. The engine just gets hot (the dash gauge only goes to 1/2) and losses fluid from Only the overflow tank. I have a new radiator, new hoses and a new thermostat (2). I put a temp gun on the lower hose and it is about 160-173 and the upper is about 180-193. At one time the lower hose was at 173 and the upper at 181 while the temp gauge on the dash was at 1/2 (high for my car). The temp gauge now always gets to 1/2 when for years it never passed 1/4. The coolant does not seem to overflow (do to high temp) unless I use the heater but I am still losing coolant weekly regardless. I water lever light comes on regardless about every other day. I only can add about 16oz of water (not really low). There is no leak in the system at all for sure! I used to be able to turn the AC on (only one fan for all) to get the fan to cool the motor when I did have a leak but now this does nothing to cool even when the fan is running... ? When the car was all good and would only get to 1/4 on the temp gauge it could set for 20 minutes and be back down to nothing (cold) even in the summer heat but now it takes 2 hours or more to sit and cool even in very cold weather. I know from this that the car is in fact hotter than normal. For years the gauge was at 1/4 and stayed put but now it never stays at 1/4 even in 30 degree weather. The thermostat is the second I have put in and there is only one model I can use and both open at the same temp because they are the same.

I want to think that the water pump is working, just very poorly and needs to be replaced but the cost is 300$ and I want to make sure it is this before I replace it.

Can anyone help me please, I never heard of a water pump broke or working poorly without a leak or noise. And my pump seems to be working but only at about 50% to 20% of what it should be, is this possible???

Thanks!!!

My first thought would be to check the radiator cooling fan while the car is running, to make totally sure that fan works and works well. Next thought would be to check and maybe have an engine coolant flush done. Perhaps, there is a build-up in the engine water passages what is preventing the coolant from performing up to grade. I agree, that changing out a $300 part without checking and eliminating other possibilities is not a proper way to manage your money ......

Thanks.. The fan works both for AC and for motor temp. I did not think about a flush for a clog in the motor itself.. Do you know if the water pump parts for this model are plastic or metal?

Water pumps leak all the time without making noise.

This system has no known leaks. I only add coolant because it is getting hot and boiling over out the overflow tan value. My dash temp gauge has always sat a just over 1/4 even sitting in summer at idle. Now mine goes to 1/2 even while driving 45-60 mpr in 30 degree weather...


Where does your SW2 dash temp gauge sit at, just over 1/4 or nearer to 1/2?

Thanks greatly for your help!

Every S-Car I have had would run up to 3/4 at some point and the fan would switch on.

I'll comment here with respect to my 94SW2 ... 1/4 to 3/8 is where the temp runs on this car. Did manage to get it above halfway once, but that was due to a defective thermal switch, which was quickly replaced.

The reason I suggest an engine flush is that in the late 90s and early 2000s, there was a compatability problem between Prestone and Dexcool - causing a "gunky" condition inside the engine. Dunno if that's the case here, but it couldn't hurt ...

It sounds like your ECTS is acting up and not sending an accurate signal. Normally when the temp gauge hits 3/4 to 7/8 scale, the PCM signals the fan to come on. It gets this info from the ECTS. Your car never reaches this point so the fan never comes on. (you said the gauge goes to 1/2 and the engine boils over). In other words, the engine is hotter than the gauge indicates. That is because the ECTS is bad. I had more than one S car that acted the same way as yours- I replaced the ECTS on them and never had another boil over issue.

Hoseppi may have the answer. Just for the record, when you change the ECTS, change the connector as well (loose connections and all that). Total cost of parts outlay will be around $40usd. Make sure the new ECTS has a brass tip (not a resin tip), and use Teflon tape on the threads.

Thanks for the advice, I think I will get an engine flush and see if that fixes it running hot... if the gauge is still off but not overheating I can live with that!!!

Thanks again guys!!!