: strange overheating problem ................. Let's hear your input



ascariSTS
05-28-09, 09:22 AM
All,

I'm having a strange overheating problem.. since I'm not that good in the mechanical side, I would like to hear from professionals here...

I'm actually having 2 main problems:

1- after I drive for a long time, I stop and turn off. I go into a shop, and come back after 3 or 4 minutes. When I start the engine, the engine temperature gauge is about 75%, while the normal is about 45% ... in 10 seconds, the gauge returns back to normal... that's if i start the engine after about 4 minutes.. if i start it after 10 or more minutes, the gauge is normal... it's just that short time after the engine turns off after driving for a long time...

I was thinking about it.. when the engine is running, it's the coolant water and the fan that keeps the engine's temperature normal... But after I turn off, what should keep it normal ?... is the fan supposed to be on for minutes after i switch off the engine ?...

that wasn't happening before...


2- A new issue, happened a year ago.. When it's summer, the temperature here reaches 50 C... When the engine on, car is stopped for sometime, gauge raises slowly above normal... when i drive, it goes back to normal immediately... that's also wasn't happening before.


I'm not sure if this might help investigating the problem, but put in your mind two things:
1- there is absolutely NO overheating when driving... at all
2- i'm not sure if the fan has anything to do with this. if it's a variable speed fan or not, if it's on electricity, or needs reprogramming.

I would like to hear your inputs coz it's very annoying especially here in our country where summer is very hot..


ascarists

next2pool
05-28-09, 11:50 AM
The first issue is called heat soak and is completely normal and doesn't hurt anything. For quite a while, some car makers (esp the Europeans) would turn on the fans to bring the temp back down, but this caused lots of anxiety among owners who didn't understand why that was happening. It can also cause injuries when people are working under the hood and the fan comes on. The second issue is not normal and I suspect the fans are not working or coming up to speed as designed. The ram air effect from moving tends to bring the temp back down. With the engine running you should see little if any movement of the gage whether you are sitting or moving.

ahuyghe
05-28-09, 01:56 PM
All,

I'm having a strange overheating problem.. since I'm not that good in the mechanical side, I would like to hear from professionals here...

I'm actually having 2 main problems:

1- after I drive for a long time, I stop and turn off. I go into a shop, and come back after 3 or 4 minutes. When I start the engine, the engine temperature gauge is about 75%, while the normal is about 45% ... in 10 seconds, the gauge returns back to normal... that's if i start the engine after about 4 minutes.. if i start it after 10 or more minutes, the gauge is normal... it's just that short time after the engine turns off after driving for a long time...

I was thinking about it.. when the engine is running, it's the coolant water and the fan that keeps the engine's temperature normal... But after I turn off, what should keep it normal ?... is the fan supposed to be on for minutes after i switch off the engine ?...

that wasn't happening before...


2- A new issue, happened a year ago.. When it's summer, the temperature here reaches 50 C... When the engine on, car is stopped for sometime, gauge raises slowly above normal... when i drive, it goes back to normal immediately... that's also wasn't happening before.


I'm not sure if this might help investigating the problem, but put in your mind two things:
1- there is absolutely NO overheating when driving... at all
2- i'm not sure if the fan has anything to do with this. if it's a variable speed fan or not, if it's on electricity, or needs reprogramming.

I would like to hear your inputs coz it's very annoying especially here in our country where summer is very hot..


ascarists

For problem 1 I agree with next2pool. It's just heatsoak and is a normal occurrence.

Problem 2 sounds to me like your thermostat is beginning to fail and not opening and closing at the proper temperature intervals.

Al

Superjim
05-28-09, 07:15 PM
Dang...you live in a really hot place.
50c is over 120F.

The first problem is normal.

For the second one, I would investigate if the electric fans are coming on at the proper times.

The fans are variable speed.
They may just be coming on, on low speed and not going to high speed as needed.

Texas Jim

EChas3
05-28-09, 09:11 PM
Does this car have V03 - PERFORMANCE COOLING PACKAGE? If so, the fan is not electric and I would suspect the thermostat as described. Please get it looked at, we would all hate to see worse problems due to chronic overheating.

ascariSTS
05-29-09, 05:51 AM
Well, first of all, you are saying first point is normal... No, it's not.. it wasn't doing that before... the dealer changed the thermostat and the gasket, and then it started... yesterday i drove for like 1.5 hrs, switched off and went into a shop for about 3 minutes, when i came back and started it, the gauge was almost on the Red area !!... 10 seconds later, it went back to normal... so i don't think it's normal...

for the second one... I doubt it's the thermostat, coz it's not going above normal when i'm driving... might be the fan... but isn't there anything else that might be the cause other than these two ?

For the package, it has the V08 - Cooling System: Heavy Duty... that's what the specs sheet says... is it electric or not ?

Angus Young
05-29-09, 06:07 AM
I have the 1SG package and my fan isnt electric, again if you live in an area where its over 50c I would also say that is normal, I would suspect the fan clutch is weak. Or mabye replace the temp sensor

ascariSTS
05-29-09, 06:20 AM
believe me this is not normal... i had the car over 3 years, sometimes the temperature reads 60 C in here... never went above normal no matter how long i drive...

there is one thing i have to mention.. I had an accident a year after i bought it.. the accident didn't reach the engine... they changed the front bumper, fans, and the rest of the stuff in the front... only after that, the second problem started to appear, which is overheating when temp is high, car is on and im not driving...

2 years later ( 1 month ago), something was leaking... took it to the dealer, the said it in one of the hoses (coolant water)... they replaced the hose with a new one, replaced the thermostat, and a gasket (don't remember which gasket)... only after that, the first problem appeared, which is overheating after switching off...

Im not sure if this helps identifying the problem...

EChas3
05-29-09, 04:15 PM
I have the 1SG package and my fan isnt electric, again if you live in an area where its over 50c I would also say that is normal, I would suspect the fan clutch is weak. Or mabye replace the temp sensor

I'm not sure 1SG includes V03. My 1SG has AWD and the V03 shows on the build sheet. My understanding is that this is a mechanical fan. Funny thing - I haven't looked!


ascariSTS - I'm sorry to say that I feel a sinking feeling about your issue. At idle you're not getting good cooling. Even in that heat the difference between the coolant and ambient air is close to 50C, plenty to cool an engine unless under very heavy load. Do both symptoms happen at night, too? What low temperatures do you have?

There's a chance it could just be air trapped in the cooling system but it acts like something more serious. I had a Buick Roadmaster that needed to be 'burped' after any cooling system work.

Angus Young
05-29-09, 08:24 PM
I just checked on my 05 1sg, my fan is not electric, it has a clutch, if you try to spin your fan it should be rather stiff to spin, if you say it isnt cooling at idle then it is most likely the fan clutch, the fan clutch will stay engaged at lower rpm's keeping the fan spinning, however once you reach cruising rpm's the fan clutch will release to conserve power from the engine, if you think back in the day we used to put flex fans on our cars to increase proformance and remove the stock clutch fan, the flex blades will straighten out when the rpms went up to reduce drag on the engine and the blades would go back to normal at idle to increase air movement thru the radiator, the fan at hiway speeds offers little to the overall cooling but is a must when when driving around town and between lights, also the fan is used to cool the air conditioning condensor if you notice your a/c getting warmer when you stop at a light .... "And there's your sign"

EChas3
05-29-09, 09:54 PM
Let's eliminate doubt. Go open your trunk, pull up the spare tire cover. There should be a label with a bunch of codes. If you see 'V03' you have a mechanical fan clutch. If so, the fan clutch is about the only thing that can fail with the fan. It cannot run unless the engine is running and you can check the fan clutch as decribed by Angus Young. Open the hood, take off the engine covers and try to move the fan.

If no 'V03', you have electric cooling fans that may not be running properly. In that case, have a technician check it out. Traditionally, electric fans run whenever the engine is hot (gauge at 40% or higher). I don't think electric fans on the STS will run when the ignition is off, but it is not worth getting hurt. Anyone sure about this?

If the fan (either type) is running properly, then it has to be coolant or its circulation (water pump). Water pumps can lose the ability to pump and still not leak. It may be rare, but it can happen. Small blockages can develop. If there was an accident, a small component could easily become lodged in the cooling system. The search may be hard but necessary. I don't want to learn what it costs to replace or rebuild a N*.

Good luck and let us know. There are lots of us that want to help.

AllWheelEric
05-30-09, 08:08 PM
Let's eliminate doubt. Go open your trunk, pull up the spare tire cover. There should be a label with a bunch of codes. If you see 'V03' you have a mechanical fan clutch. If so, the fan clutch is about the only thing that can fail with the fan. It cannot run unless the engine is running and you can check the fan clutch as decribed by Angus Young. Open the hood, take off the engine covers and try to move the fan.


From the STS ordering guide, the definition of V03 seems to include multiple fans: "Performance Cooling Package, includes P/S cooler, mechanical engine driven fan and (2) 80 watt pusher electric fans" AscariSTS mentioned V08, which I don't find in the ordering guide. Perhaps it's unique to cars destined for export to extreme climates.

EChas3
05-30-09, 11:54 PM
Thanks for setting me straight, AWE. I may pull the covers & take peak tomorrow.

ascariSTS
05-31-09, 03:34 AM
thank you all for your inputs...

As you said, I think V08 is a special package for our climate. The car's overall package is 1SK. Have you heard about that ?

anyways it seems all have agreed that it has to do with the fan. No I found in my car 3 fans. 1 big fan close to the engine and 2 small fans right behind the grill.

I dropped the car at the dealer and the guy there told me small fans should start if the engine is hot to bring the temperature down through the water reservoir (has to do with water density and stuff i don't really get)... even when the car is off it should start, as I was told.

they are going to call me today and tomorrow to tell me what they have found. I will update you.

jimzilla
06-07-09, 02:31 PM
Hello all....Normal operation for STS is Lo speed fans come on at 202F, and Hi speed fans come on at 220F. If you shut car off and water temp is above 214, the fans stay on for 60 seconds or until temp drops below, otherwise max run time is 4 minutes after shut off regardless of temp.
My 2 cents...about changing gage temperatures quickly.... I have noticed this in N* vehicles especially that have some miles on em and the gasket is gone but not completely...Like a 4000 lb car doesnt take off the line very quickly....water doesnt change temperature quickly either....because it has a high thermal mass analogous to weight of vehicle. Air however does, because it has a low thermal mass...especially when compared to water. Heat soak is certainly an issue, but soak increase is typically in the order of 10 degrees F. If you have an air bubble....the air will act as an insulator and allow the temp of what it is attached to (typically hotter than the water that is trying to cool it down)...and the reported temperature will rise quickly as it is not in direct contact with water but only the metal (intake manifold). If you notice it hot and when you start motor it drops quickly, chances are its the water pump circulating the water and pushing bubble around into reservoir tank.
If it happens quickly, it probably isnt the water temperature that is changing.

EChas3
06-07-09, 02:35 PM
Hello all....Normal operation for STS is Lo speed fans come on at 202F, and Hi speed fans come on at 220F. If you shut car off and water temp is above 214, the fans stay on for 60 seconds or until temp drops below, otherwise max run time is 4 minutes after shut off regardless of temp.
My 2 cents...about changing gage temperatures quickly.... I have noticed this in N* vehicles especially that have some miles on em and the gasket is gone but not completely...Like a 4000 lb car doesnt take off the line very quickly....water doesnt change temperature quickly either....because it has a high thermal mass analogous to weight of vehicle. Air however does, because it has a low thermal mass...especially when compared to water. Heat soak is certainly an issue, but soak increase is typically in the order of 10 degrees F. If you have an air bubble....the air will act as an insulator and allow the temp of what it is attached to (typically hotter than the water that is trying to cool it down)...and the reported temperature will rise quickly as it is not in direct contact with water but only the metal (intake manifold). If you notice it hot and when you start motor it drops quickly, chances are its the water pump circulating the water and pushing bubble around into reservoir tank.
If it happens quickly, it probably isnt the water temperature that is changing.

Nice info. Am I correct that you suggest air trapped in the system?

jimzilla
06-07-09, 03:53 PM
Regarding V08 option code, that should be for heavy duty cooling. three fans, one mechanical part of belt system and two electrical pullers. If the fans are on the bottom and in line horizontally this is the three fan HD. Standard duty is two fans with the fans on a diagonal as the fans are larger diameter blades than HD which has third element. I am not sure but I thought 1SK is with AWD as opposed to 1SG which equipment code for RWD.

EChas3
06-07-09, 05:12 PM
I have 1SG & AWD (Domestic). I figure 1SK is an export configuration code.

jamesbalzer
06-07-09, 05:48 PM
"Almost in the Red" means "Not in the Red." If the car has not hit the red or "danger" mark, it HAS NOT overheated. If you have had the car for three years, have you had the coolant serviced? DexCool is supposed to be good for 100K miles but as it gets older, it loses it's ability to dissipate heat. This would likely cause both your problems. Heatsoak is totally normal, especially on coolant that is a few years old. And, on the second problem, if it's 120 degrees outside your car WILL run hotter when you're not moving. Then when you start to move, airflow resumes through the radiator and you're spinning the water pump faster so it cools down. It sounds to me like everything you are describing is totally normal. There is nothing wrong with it it's just not new anymore. Service the cooling system (at the dealer, NOT Grease Monkey or Lighting Lube) and see it new coolant performs like what you're old coolant used to.....

EChas3
06-07-09, 06:05 PM
James,

He did have a leaky hose changed and other cooling system work due to an collision. I assumed the cooling system was refilled with new DexCool at that time. If I'm wrong, then you are spot on. Flush & fill with the best available mix for that extreme is an ecellent suggestion.

jamesbalzer
06-07-09, 08:24 PM
It would pay to read the entire thread prior to posting......

jimzilla
06-07-09, 09:45 PM
Does the vehicle have option codes V03 or V92? There is an aux electric water pump with these options that circulates the water under elctronic control. If these options appear on the list in your trunk, this pump was present and functional ....did the repair tech install and connect it? Is it functioning? Its near the front of the engine.....possibly in your collision zone....just a thought.
For general information antifreeze doesnt dissipate heat, it is a medium for heat transfer. Antifreeze when mixed properly provides a wetting agent (for heat transfer), lubricant for water pump, anti rust agents, and wi;l not freeze like water, below 32F. The wetting agent is the significant issue as it tightly couples (w/o boiling) the heat in the engines water jacket and is able to carry it (absorb the heat) to the radiator which provides the opposite end of the heat transfer. The radiator takes the hot water tightly coupled to its core and passes air over it (even at 120F) the water is much hotter at >210F and above, so heat flows naturally from Hot to Cold. The return water out of the radiator is significantly cooler than what came in from the engine. The speed of the water pump and aux pump provides the proper amount of hot water to be cooled. Age of mixture doesnt effect much especially in 5 years or less...I have seen many a vehicle with 15 year old ( I dont suggest it) antifreeze, and the vehicle runs fine thermally. The antifreeze mix would have to be significantly water before a problem would be present, from my experience. The antifreeze if mixed improperly however (incorrect ratio with water...either too little or too much will effect in this case lower the temp at which the mixture boils. The cap however provides 13- 15 psi which provides most some of the extended temperature (higher boiling point than 212F. Boiling over provides air bubbles which could be part of your issue...Another question though...did the engine run for a while after the collision...could it have over heated and ruptured the heat gasket? The slight head gasket leak would allow combustion chamber gasses at high pressure (> 200 psig) to pass into the water jacket (only 15 psig) and this would show up as a bubble....and sometimes spit out fluid from overflow. The water would not necessarily leak into chamber causing white smoke on startup. Check fluid level over a few week time period, see if you are losing any.
Almost in the red is a caution...if you wait til its in the red, then you'll have a more serious problem....thats why they used to call those bulbs...idiot lights. Obvioulsy if this isnt what you were used to seeing before and it has changed suddenly you are on to a problem that is close or about to be a bigger problem. I have driven a 95 Seville, a 97 an 02 05 and an 08 Cadi....all with N* and only one got close to the red....eventually it bled...Its your car and if you notice a change have it explored....
I believe the other gentleman that indicated the 1SK is export is probably right...as I dont know equipment codes, but ventured a surmise, sorry for the confusion.

EChas3
06-07-09, 10:29 PM
It would pay to read the entire thread prior to posting......

Jimzilla did you see the above post?

ascariSTS stated he has V08 (a code only found in export models.) A lot of guys use wetting agents other than OEM. I think we are suggesting Ascari check to make sure he has the best available coolent mix.

Unfortunately, a slight gasket leak can easily cause the odd behavor noted. When my wife's '98 started to have trouble it was only under severe conditions and rare even then.

If it persists, Stopleak is worth a try. It lengthened the life of a lot of N*. This is the first case I've heard of one of the new ones possibly having the old issue.

jamesbalzer
06-08-09, 12:42 AM
NO STOP-LEAK!!!!!!!! This will make it worse in the long run. Stop Leak should be outlawed for the mayhem it causes inside the engine and will only make it near impossible to fix properly down the road! DO NOT USE STOP LEAK!!!!!

EChas3
06-08-09, 07:30 PM
NO STOP-LEAK!!!!!!!! This will make it worse in the long run. Stop Leak should be outlawed for the mayhem it causes inside the engine and will only make it near impossible to fix properly down the road! DO NOT USE STOP LEAK!!!!!

OK OK OK Don't melt down! :thehand:


Before doing something stupid (like I suggested) - Flush & Fill with the proper mix of DexCool and make sure they get all the air bubbles out of the system. If the problems repeat, get the coolent tested for exhaust gases (i.e. emission control testing works). Even a small head gasket/crack will 'pollute' the coolent.

If testing is not available locally, I'll bet there's a lab that will test a sample, somewhere. :stirpot: