Cooling Fans Question

[BodybyFisher]

Check with others with the analog gage, that might be normal

Have you changed the thermostat and used an OEM stat? OEM

Have you flushed the system, used 50/50 dexcool with distilled water and used the cooling supplement?

Check that the radiator is not clogged with leaves and debris, when the engine is cool I shoot a high pressure hose through it

Do you smell any coolant at all? I needed crossover seals and smelled coolant for 2 years, once I replaced them, NO coolant smell and she runs cooler

You are running 89, are you getting any knock at all pulling away from the curb when hot? See this article on retarded timing relative to overheating

http://answers.yahoo.com/question/index?qi...23174554AAm2kZd

If all of the above is fine, I would stop worrying about it and drive it.

[JimD]

Well I tell ya what, After a 98 degree day the fans needed to be on at all times! The car went to 1 line past the 12 oclock position ....

One tick past 12 o'clock is a long way from "hot".

The picture below is my '98 Seville temp. guage and I was not the least little bit concerned about forcing the temp. to the 2nd tick past 12 o'clock. I would get nervous at 270 degrees.

http://i70.photobucket.com/albums/i101/Jim...withnumbers.jpg

[BodybyFisher]

Thanks Jim, that is what I thought. Relax FIVE... fix your cooling fan relay and drive it. Do you want the cooling fan schematic?

[BodybyFisher]

If you go to page 2-71 of your owners manual, you have a light that comes on if you are overheating, in addition, your analog gauge appears to indicate overheating about a 1/4" from H, see your PDF manual here:

https://www.mygmlink.com/pdf/go2content/man...1996seville.pdf

[BodybyFisher]

Here are the cooling fan schematics

[fivepointohman]

Here are the cooling fan schematics

Thanks body, Ill be looking into all of this today! I appreciate the research!

[BodybyFisher]

No problem look at my post #23 here and it will help you follow the schematic, Mike

[JasonA]

My '01 STS's gauge won't move off the middle mark at all, even in the 100*F+ temperatures we've had here. Five, are your fans always on in the "LOW" mode or in the "HIGH" mode?

[BodybyFisher]

My '01 STS's gauge won't move off the middle mark at all, even in the 100*F+ temperatures we've had here. Five, are your fans always on in the "LOW" mode or in the "HIGH" mode?

Neither, his RH fan was not working at all, in LOW, we never determined if it was working in HIGH, I would love to see FIVE do that test, that is why I said to COVER THE RADIATOR and get the temp up. If you look at RELAY #2, it has TWO CONTACT SIDES to it, a LOW side and a HIGH side that is engergized by the PCM. I feel his LOW SIDE contacts are burned, and if he let the PCM envoke the HIGH fan mode, the RH motor would have RUN. THAT is unless he has a broken wire which is easily traced back to the relay using an ohm meter or continuity tester.

[Cadillac Jim]

Couldn't you test the high speed fans by pulling off the ECT sensor wire? If they don't come on, then short it to ground.

Naah, that would throw lots of codes, shut off the A/C, and make the PCM mad.

[fivepointohman]

My '01 STS's gauge won't move off the middle mark at all, even in the 100*F+ temperatures we've had here. Five, are your fans always on in the "LOW" mode or in the "HIGH" mode?

High mode

[JasonA]

So your temperature gauge still moved off the center mark even though both fans are running on HIGH? Or is one just running on HIGH?

Edit: it looks like from page 1 that you've successfully got BOTH fans running now off your toggle switch, yes? If they're both running on HIGH, and the temperature gauge is still moving around, I would suspect at least one other problem. The temperature gauge will start to move when the coolant reaches about 229*F...then the fans kick on low speed (if the A/C isn't already on). Then at about 235*F, the fans kick on high speed. On high, the fans should EASILY cool the engine off.

Again, if you've got your fans locked on, either low or high actually, and your gauge is still moving around some, I'd keep looking for the problem.

[BodybyFisher]

So your temperature gauge still moved off the center mark even though both fans are running on HIGH? Or is one just running on HIGH?

Edit: it looks like from page 1 that you've successfully got BOTH fans running now off your toggle switch, yes? If they're both running on HIGH, and the temperature gauge is still moving around, I would suspect at least one other problem. The temperature gauge will start to move when the coolant reaches about 229*F...then the fans kick on low speed (if the A/C isn't already on). Then at about 235*F, the fans kick on high speed. On high, the fans should EASILY cool the engine off.

Again, if you've got your fans locked on, either low or high actually, and your gauge is still moving around some, I'd keep looking for the problem.

Oh I misunderstood your question, you mean since five rewired his cooling fans right?

[JasonA]

Oh I misunderstood your question, you mean since five rewired his cooling fans right?

Yes, that's right. If his fans are locked on, and both are working, the temperature gauge shouldn't be moving around at all, regardless of cooling fan speed. Those fans being on low all the time should be enough to keep that coolant temperature pretty dadgum steady.

[fivepointohman]

Oh I misunderstood your question, you mean since five rewired his cooling fans right?

Yes, that's right. If his fans are locked on, and both are working, the temperature gauge shouldn't be moving around at all, regardless of cooling fan speed. Those fans being on low all the time should be enough to keep that coolant temperature pretty dadgum steady.

I ran the car around saturday nite, temps outside around 79-83, car ran steady around 190 degrees, + or - 10 degrees, even at a dead stop in city traffic. this car has an original water pump that concerns me, I think I should just change it out as a preventative having 127K on it.

[JasonA]

So what were the conditions under which the gauge was moving around on you a few days ago? Do you remember what the actual coolant temperatures were? 190 +/- is right at where my '97 would run. With A/C use (and the fans cycling on/off) and hot weather and traffic, it'd run around the 205-215 area. But again, that's with the fans cycling on/off. With the fans locked on, I believe it would have run under 200*F all day, like yours apparently did on Saturday.

[BodybyFisher]

Oh I misunderstood your question, you mean since five rewired his cooling fans right?

Yes, that's right. If his fans are locked on, and both are working, the temperature gauge shouldn't be moving around at all, regardless of cooling fan speed. Those fans being on low all the time should be enough to keep that coolant temperature pretty dadgum steady.

I ran the car around saturday nite, temps outside around 79-83, car ran steady around 190 degrees, + or - 10 degrees, even at a dead stop in city traffic. this car has an original water pump that concerns me, I think I should just change it out as a preventative having 127K on it.

How do you know its the original water pump? Why create problems, if it leaks, change it, otherwise, why? 190 degrees to 200 degrees is good. Did you connect the fans in a parallel or series, you have them running full speed? Just keep in mind that you are putting an additional drain on your charging system and that at night with lights, AC, wipers on, and the fans running at full speed, you might find your charging levels dropping below 12 volts.

[thaghost87]

how can you tell the actual temp by reading the the temp gauge? when im at a long light or idle my car for a little my gauge goes a lil past the half mark, but never seen it go much futher...

[JasonA]

You cannot tell on a '98+ STS. Prior to '98, you could actually program the Driver Information Center to display the digital temperature. It became one of the choices when scrolled through the data with the INFO button.

[thaghost87]

You cannot tell on a '98+ STS. Prior to '98, you could actually program the Driver Information Center to display the digital temperature. It became one of the choices when scrolled through the data with the INFO button.

I See... so is that normal for cars to do that? (when im at a long light or idle my car for a little my gauge goes a lil past the half mark, but never seen it go much futher...)

[catmendo]

Dana F, i now see that you are a supporter, as you said, that you were going to do ...

i like a man of his word !!! good deal sir ...

Lane

[thaghost87]

Dana F, i now see that you are a supporter, as you said, that you were going to do ...

i like a man of his word !!! good deal sir ...

Lane

THANKS... just showing my appreciation of all the support i have recieved, and hopefully can be of some help down the line to someone..!

[BodybyFisher]

I used to be a fanatic about temps, but the guru calmed my fears about it.

Owners that have digital gages can be on edge watching the numbers rise with their blood pressure, there was a question as to whether or not the digital gauge was a good idea, because it was real-time and unbuffered and freaked owners out. But once you have properly maintained your cooling system, including all seals, hoses, pipes, stat, flush, 50/50, replace end tanks etc, there is no reason to panic, trust the engineers. The NS waterpump pumps an incredible amount of coolant each minute and the cooling system. is very efficient.

Five is nervous because his guage IMPLIES he is overheating because its over half, which in the OLD DAYS was true, as the gages were calibrated to run in the 1/4 to 1/2 range and as it approached 1/2 it was bad. That is not the case with his car, it runs NORMAL at 1/2, that is why in my first post I said, check with others that have the ANALOG temp guage that might be NORMAL. Add to that that FIVE made the statement that he didnt want to OVERHEAT and BLOW the head gaskets, and you see that he has unfounded FEARS, as NORMAL temps in the 192 to even 245 are NOT the cause of head gasket problems.

He has 'FIXED' his "problem" by hard wiring his fans to run at FULL SPEED when he does not need to, his perceptions are that his NS runs too hot and he has superceded the design engineers to make it 'better' when there was no reason. Its sort of like killing an ant with an anvil. totally unnecesary.

Five your fears are illogical and unfounded and to me you have damaged your car hardwiring it and defeated normal function by direct wiring your fans. Have you ever seen the RED LIGHT come on? Doubtful, because its not overheating.. Its one thing replacing a defective fan relay, its quite another rewiring your electrical system to overkill a non existant problem. Peoples fears are illogical however, Five has his cooling system running at 190 + 10 degrees but he is NOW talking about replacing a functioning water pump, ALL because he thinks that an engine running in normal temp ranges (192 to 235 EVEN 240 at time) is NOT normal and that those temps cause head gasket problems, which is NOT true. I have a digital temp guage and SUMMER temps in the 192 to 240 range are NORMAL depending upon the outside temps, and with analog gages, 1/2 is normal and there is a LIGHT. We are all free to hatchet our cars as we wish, but ignoring facts is just plain dramatic, foolish and overkill. Please don't take this as an attack Five or as criticism, its not.

Over the last 2 years I have done the following to my 1996 cooling system, I now have very stable temps, no coolant smells, and I NEVER worry, as I know that I have removed all potential problems that could spring a leak under high temp/pressure summer traffic conditions.

I was in 60 miles of bumper to bumper traffic last August with 100 to 105 outside temps on Route 95 with my 9 year old daughter in the car and my temps ranging from 212 to 245 and I did not get nervous or sweat a drop with the AC blazing cold, because of all of the work I itemize below. Its all about inspecting your cooling system and replacing any weak points and fixing leaks (seals, end tanks), etc and TRUSTING the design engineers and just DRIVE IT..

Replaced radiator (end tanks were leaking under pressure, had white residue)

Replaced heater pipes at rear of engine as they were rusted badly, members said, ahh just paint them, if you look at KenD's recent heater pipe leak, you know why I replaced mine

Replaced the crossover seals, BIG JOB, source of coolant smell seals cracked and damaged

Replaced the GREEN silicone hoses and clamps, un-necessary but I was there

Replaced the water pump by-pass hose, PM

Replaced the three rubber hoses near the tank, PM

Removed and cleaned the bleed bolt, PM/Cleaning

Flushed and renewed Dexcool

Used cooling supplement tablets

Replaced upper and lower radiator hoses, old hoses good, did PM

Replaced thermostat with OEM stat, PM

Replaced cap, PM

Replaced water pump and belt, unnecessary, old pump on bench

Result, perfect cooling system, no coolant smell, low temps, tight ranged and when the temps hit 235 to 240, I know its the result of high outside temps and I have no fears

[JasonA]

I See... so is that normal for cars to do that? (when im at a long light or idle my car for a little my gauge goes a lil past the half mark, but never seen it go much futher...)

In general, yes, it's normal...especially if you're not using A/C.

Cooling fans are controlled by two main inputs: the A/C and the coolant temperature. Without A/C use, the cooling fans are controlled entirely by coolant temperature. They will remain off until the coolant reaches a temperature of about 229*F. Your temperature gauge will start to come off the "straight-up" mark at about 220-222*F in my experience (from my '97 SLS). So pretty soon after you see the gauge start to move a little, you should hear the cooling fans engage (on LOW speed), and the gauge will soon thereafter return to "straight-up". The cooling fans turn back off at around 212-215*F as I recall. If the engine coolant temperature gets up to about 235*F, the fans change from LOW speed to HIGH speed. They return to low speed in the 220*F range I believe.

Now, all that is without A/C. If the A/C is on, regardless of engine temperature, the cooling fans will cycle on and off. This is because there is an immediate thermal load on the A/C condenser, and it needs airflow across it to exchange heat with the air. So the fans will cycle on and off if your A/C is on. 90% of the time, this is enough (the fan cycling, on LOW) to maintain coolant temperature in the 200-220*F range. I've never seen the temperature gauge on my '01 STS come off "straight-up", ever. But I also don't use it under real extreme circumstances, either. I don't sit in traffic for hours on 100*F days with it. Under those extreme circumstances, the fan cycling may not be enough to maintain coolant temperatures, and the gauge might start to creep up. When it gets to around 229*F, the fans will change from a cycling to a constant on (again, in LOW speed). And like before, without A/C use, if the temperature does creep up further to 235*F, the fans will change from LOW to HIGH.

[BodybyFisher]

Dana F, i now see that you are a supporter, as you said, that you were going to do ...

i like a man of his word !!! good deal sir ...

Lane

THANKS... just showing my appreciation of all the support i have recieved, and hopefully can be of some help down the line to someone..!

That's great Dana glad you are a supporter now..