If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
94 SL2 Overheating
Hi,
I have a 94 saturn SL2 that's overheating. So far I've done the following: 1. The coolant doesn't leak 2. The radiator is new 3. Connected the radiator fan to the battery and the fan spins 4. Had a mechanic look at all the fuses and relays, all are fine. 5. Had three mechanics told me that it's the temperature sensor (one of them) So my question is as follows: My Hanes manual says that I should replace the thermostat. Is the thermostat the same as the temperature sensor? If not are there instructions on replacing it? Where would I get the part numbers for what I need? Thanks, Andrew |
Ads |
#2
|
|||
|
|||
94 SL2 Overheating
To clarify a bit,
the car overheats when it is sitting idling. If I'm driving over 30 or 40 mph the temperature comes back down. Thanks, Andrew Andrew E. wrote: > Hi, > > I have a 94 saturn SL2 that's overheating. So far I've done the following: > > 1. The coolant doesn't leak > 2. The radiator is new > 3. Connected the radiator fan to the battery and the fan spins > 4. Had a mechanic look at all the fuses and relays, all are fine. > 5. Had three mechanics told me that it's the temperature sensor (one of > them) > > So my question is as follows: > > My Hanes manual says that I should replace the thermostat. Is the > thermostat the same as the temperature sensor? If not are there > instructions on replacing it? > > Where would I get the part numbers for what I need? > > > Thanks, > Andrew |
#3
|
|||
|
|||
94 SL2 Overheating
On Fri, 22 Sep 2006 17:29:30 -0400, "Andrew E."
> wrote: >To clarify a bit, > >the car overheats when it is sitting idling. If I'm driving over 30 or >40 mph the temperature comes back down. > >Thanks, >Andrew Sounds like the radiator fan isn't turning on. There is enough airflow over the radiator when driving and the fan isn't needed. Stop moving and it eventually has to come on to prevent overheating. I always thought there should be some indicator that the fan is on. It's a handy thing to know. Does your car have A/C? Turn that on and see if the fan starts. Then you know the wiring to the fan is OK. >Andrew E. wrote: >> Hi, >> >> I have a 94 saturn SL2 that's overheating. So far I've done the following: >> >> 1. The coolant doesn't leak >> 2. The radiator is new >> 3. Connected the radiator fan to the battery and the fan spins >> 4. Had a mechanic look at all the fuses and relays, all are fine. >> 5. Had three mechanics told me that it's the temperature sensor (one of >> them) >> >> So my question is as follows: >> >> My Hanes manual says that I should replace the thermostat. Is the >> thermostat the same as the temperature sensor? If not are there >> instructions on replacing it? >> >> Where would I get the part numbers for what I need? >> >> >> Thanks, >> Andrew |
#4
|
|||
|
|||
94 SL2 Overheating
In article >, "Andrew E." > wrote:
>Hi, > >I have a 94 saturn SL2 that's overheating. So far I've done the following: > >1. The coolant doesn't leak How did you determine that? Just checking for drips underneath the car isn't enough -- for example, a leaking head gasket could leak coolant into the combustion chambers where it will be evaporated and blown out the tailpipe, and you'll never see any drips. Have you verified that the cooling system actually is, and remains, full? >2. The radiator is new Why? >3. Connected the radiator fan to the battery and the fan spins >4. Had a mechanic look at all the fuses and relays, all are fine. >5. Had three mechanics told me that it's the temperature sensor (one of >them) I doubt it. It's possible that a failed temperature sensor is causing overheating by preventing the electrically operated fan from coming on -- but as long as the vehicle is moving at any appreciable speed, there's enough air being forced through the radiator that the fan isn't really needed for cooling, so this is unlikely IMO unless you're doing a lot of driving in very heavy stop-and-go slow speed traffic. The more likely symptom of a failed sensor is a gauge that's *falsely* reporting the engine to be too hot, when the temperature is actually normal. IS the engine actually overheating? (Noticeably hotter than normal when you lift the hood, smell of hot coolant, wisps of steam drifting out from under the hood, clouds of steam pouring out, etc.) If so, I'm betting the problem is a failed thermostat. *Especially* if the thermostat wasn't replaced at the same time the radiator was. (It should have been. They're cheap, and they fail fairly regularly in older vehicles. As long as the cooling system is drained anyway, it's just silly not to replace it.) > >So my question is as follows: > >My Hanes manual says that I should replace the thermostat. I agree. :-) >Is the >thermostat the same as the temperature sensor? It is not. The temperature sensor does just that: senses the temperature, and sends a signal to the temperature gauge. The thermostat controls how hot the engine gets; specifically, the thermostat is a valve that sits between the engine and the radiator. It stays closed until the coolant reaches the correct temperature (190F, I believe), and then opens. This prevents water from circulating through the radiator until the engine is warmed up. If the thermostat is stuck open, the engine takes a very long time to warm up (which is bad in a variety of ways) -- and if it's stuck *closed* (or doesn't open fully), the engine overheats. Of course, that's also bad. :-) >If not are there >instructions on replacing it? If you have the same Haynes manual that I do, it's on pages 3-2 and 3-3. Or you could look in the index under "Thermostat, check and replacement". The instructions for checking and replacing the temperature sensor are a few pages later, listed under "Coolant temperature sending unit - check and replacement". > >Where would I get the part numbers for what I need? You should be able to find a thermostat for your car at just about any auto parts store, or maybe even in the automotive department at Wal-Mart. -- Regards, Doug Miller (alphageek at milmac dot com) It's time to throw all their damned tea in the harbor again. |
#5
|
|||
|
|||
94 SL2 Overheating
From what you state, it sounds like either a failed coolant temperature
sensor or the fan relay. Bob "Andrew E." > wrote in message ... > To clarify a bit, > > the car overheats when it is sitting idling. If I'm driving over 30 or 40 > mph the temperature comes back down. > > Thanks, > Andrew > > Andrew E. wrote: >> Hi, >> >> I have a 94 saturn SL2 that's overheating. So far I've done the >> following: >> >> 1. The coolant doesn't leak >> 2. The radiator is new >> 3. Connected the radiator fan to the battery and the fan spins >> 4. Had a mechanic look at all the fuses and relays, all are fine. >> 5. Had three mechanics told me that it's the temperature sensor (one of >> them) >> >> So my question is as follows: >> >> My Hanes manual says that I should replace the thermostat. Is the >> thermostat the same as the temperature sensor? If not are there >> instructions on replacing it? >> >> Where would I get the part numbers for what I need? >> >> >> Thanks, >> Andrew |
#6
|
|||
|
|||
94 SL2 Overheating
Hi
>> I have a 94 saturn SL2 that's overheating. So far I've done the following: >> >> 1. The coolant doesn't leak > How did you determine that? Just checking for drips underneath the car isn't > enough -- for example, a leaking head gasket could leak coolant into the > combustion chambers where it will be evaporated and blown out the tailpipe, > and you'll never see any drips. Have you verified that the cooling system > actually is, and remains, full? Yes it remains full over several months. > >> 2. The radiator is new > > Why? > Because my other radiator cracked and I had to replace it. >> 3. Connected the radiator fan to the battery and the fan spins >> 4. Had a mechanic look at all the fuses and relays, all are fine. >> 5. Had three mechanics told me that it's the temperature sensor (one of >> them) > > I doubt it. > > It's possible that a failed temperature sensor is causing overheating by > preventing the electrically operated fan from coming on This is exactly what is happening. The fan doesn't come on even when the temperature indicator on the dashboard is way over half. As I said, the fan is fine and the relays and fuses have all been tested (by a mechanic) and are fine. If the relay is shorted the fan turns on. -- but as long as the > vehicle is moving at any appreciable speed, there's enough air being forced > through the radiator that the fan isn't really needed for cooling, so this is > unlikely IMO unless you're doing a lot of driving in very heavy stop-and-go > slow speed traffic. This is exactly when the overheating happens: during stop and go traffic. If I'm driving at an appreciable speed the engine stays at the 1/4 mark. The more likely symptom of a failed sensor is a gauge > that's *falsely* reporting the engine to be too hot, when the temperature is > actually normal. > > IS the engine actually overheating? (Noticeably hotter than normal when you > lift the hood, smell of hot coolant, wisps of steam drifting out from under > the hood, clouds of steam pouring out, etc.) > Yes I've had it steam up before and it is *very* hot otherwise. > If so, I'm betting the problem is a failed thermostat. *Especially* if the > thermostat wasn't replaced at the same time the radiator was. (It should have > been. They're cheap, and they fail fairly regularly in older vehicles. As long > as the cooling system is drained anyway, it's just silly not to replace it.) > >> So my question is as follows: >> >> My Hanes manual says that I should replace the thermostat. > > I agree. :-) So given the above do you still agree? > > If you have the same Haynes manual that I do, it's on pages 3-2 and 3-3. > Or you could look in the index under "Thermostat, check and replacement". > > The instructions for checking and replacing the temperature sensor are a few > pages later, listed under "Coolant temperature sending unit - check and > replacement". So is this what I'm looking for? Does the coolant temperature sending unit cause the engine fan to come on? >> Where would I get the part numbers for what I need? > > You should be able to find a thermostat for your car at just about any auto > parts store, or maybe even in the automotive department at Wal-Mart. > Does this apply to the coolant temperature sending unit? Thanks, Andrew |
#7
|
|||
|
|||
94 SL2 Overheating
Hi
I had the relay tested and it is fine (according to the mechanic). Does the coolant temperature sensor control when the fan comes on? thanks, Andrew Bob Shuman wrote: > From what you state, it sounds like either a failed coolant temperature > sensor or the fan relay. > > Bob > > "Andrew E." > wrote in message > ... >> To clarify a bit, >> >> the car overheats when it is sitting idling. If I'm driving over 30 or 40 >> mph the temperature comes back down. >> >> Thanks, >> Andrew >> >> Andrew E. wrote: >>> Hi, >>> >>> I have a 94 saturn SL2 that's overheating. So far I've done the >>> following: >>> >>> 1. The coolant doesn't leak >>> 2. The radiator is new >>> 3. Connected the radiator fan to the battery and the fan spins >>> 4. Had a mechanic look at all the fuses and relays, all are fine. >>> 5. Had three mechanics told me that it's the temperature sensor (one of >>> them) >>> >>> So my question is as follows: >>> >>> My Hanes manual says that I should replace the thermostat. Is the >>> thermostat the same as the temperature sensor? If not are there >>> instructions on replacing it? >>> >>> Where would I get the part numbers for what I need? >>> >>> >>> Thanks, >>> Andrew > > |
#8
|
|||
|
|||
94 SL2 Overheating
Hi,
I tried turning on the A/C and the fan does not start. Thanks, Andrew Jim, N2VX wrote: > On Fri, 22 Sep 2006 17:29:30 -0400, "Andrew E." > > wrote: > >> To clarify a bit, >> >> the car overheats when it is sitting idling. If I'm driving over 30 or >> 40 mph the temperature comes back down. >> >> Thanks, >> Andrew > > Sounds like the radiator fan isn't turning on. There is enough > airflow over the radiator when driving and the fan isn't needed. Stop > moving and it eventually has to come on to prevent overheating. > > I always thought there should be some indicator that the fan is on. > It's a handy thing to know. > > Does your car have A/C? Turn that on and see if the fan starts. Then > you know the wiring to the fan is OK. > >> Andrew E. wrote: >>> Hi, >>> >>> I have a 94 saturn SL2 that's overheating. So far I've done the following: >>> >>> 1. The coolant doesn't leak >>> 2. The radiator is new >>> 3. Connected the radiator fan to the battery and the fan spins >>> 4. Had a mechanic look at all the fuses and relays, all are fine. >>> 5. Had three mechanics told me that it's the temperature sensor (one of >>> them) >>> >>> So my question is as follows: >>> >>> My Hanes manual says that I should replace the thermostat. Is the >>> thermostat the same as the temperature sensor? If not are there >>> instructions on replacing it? >>> >>> Where would I get the part numbers for what I need? >>> >>> >>> Thanks, >>> Andrew |
#9
|
|||
|
|||
94 SL2 Overheating
Andrew,
It's time to get a schematic diagram for the car. The official Saturn manual has one, don't know about other sources. Figure out which relay pins are the coil. Pop the relay and check for voltage to the coil. Have someone turn on the A/C or something like that. Then take it from there. On Fri, 22 Sep 2006 20:16:25 -0400, "Andrew E." > wrote: >Hi, > >I tried turning on the A/C and the fan does not start. > >Thanks, >Andrew > >Jim, N2VX wrote: >> On Fri, 22 Sep 2006 17:29:30 -0400, "Andrew E." >> > wrote: >> >>> To clarify a bit, >>> >>> the car overheats when it is sitting idling. If I'm driving over 30 or >>> 40 mph the temperature comes back down. >>> >>> Thanks, >>> Andrew >> >> Sounds like the radiator fan isn't turning on. There is enough >> airflow over the radiator when driving and the fan isn't needed. Stop >> moving and it eventually has to come on to prevent overheating. >> >> I always thought there should be some indicator that the fan is on. >> It's a handy thing to know. >> >> Does your car have A/C? Turn that on and see if the fan starts. Then >> you know the wiring to the fan is OK. >> >>> Andrew E. wrote: >>>> Hi, >>>> >>>> I have a 94 saturn SL2 that's overheating. So far I've done the following: >>>> >>>> 1. The coolant doesn't leak >>>> 2. The radiator is new >>>> 3. Connected the radiator fan to the battery and the fan spins >>>> 4. Had a mechanic look at all the fuses and relays, all are fine. >>>> 5. Had three mechanics told me that it's the temperature sensor (one of >>>> them) >>>> >>>> So my question is as follows: >>>> >>>> My Hanes manual says that I should replace the thermostat. Is the >>>> thermostat the same as the temperature sensor? If not are there >>>> instructions on replacing it? >>>> >>>> Where would I get the part numbers for what I need? >>>> >>>> >>>> Thanks, >>>> Andrew |
#10
|
|||
|
|||
94 SL2 Overheating
Hi,
Already done. That's what the mechanic did: he opened the relay and shorted the coil and the fan turned on. Andrew Jim, N2VX wrote: > Andrew, > > It's time to get a schematic diagram for the car. The official Saturn > manual has one, don't know about other sources. > > Figure out which relay pins are the coil. > Pop the relay and check for voltage to the coil. Have someone turn on > the A/C or something like that. > > Then take it from there. > > On Fri, 22 Sep 2006 20:16:25 -0400, "Andrew E." > > wrote: > >> Hi, >> >> I tried turning on the A/C and the fan does not start. >> >> Thanks, >> Andrew >> >> Jim, N2VX wrote: >>> On Fri, 22 Sep 2006 17:29:30 -0400, "Andrew E." >>> > wrote: >>> >>>> To clarify a bit, >>>> >>>> the car overheats when it is sitting idling. If I'm driving over 30 or >>>> 40 mph the temperature comes back down. >>>> >>>> Thanks, >>>> Andrew >>> Sounds like the radiator fan isn't turning on. There is enough >>> airflow over the radiator when driving and the fan isn't needed. Stop >>> moving and it eventually has to come on to prevent overheating. >>> >>> I always thought there should be some indicator that the fan is on. >>> It's a handy thing to know. >>> >>> Does your car have A/C? Turn that on and see if the fan starts. Then >>> you know the wiring to the fan is OK. >>> >>>> Andrew E. wrote: >>>>> Hi, >>>>> >>>>> I have a 94 saturn SL2 that's overheating. So far I've done the following: >>>>> >>>>> 1. The coolant doesn't leak >>>>> 2. The radiator is new >>>>> 3. Connected the radiator fan to the battery and the fan spins >>>>> 4. Had a mechanic look at all the fuses and relays, all are fine. >>>>> 5. Had three mechanics told me that it's the temperature sensor (one of >>>>> them) >>>>> >>>>> So my question is as follows: >>>>> >>>>> My Hanes manual says that I should replace the thermostat. Is the >>>>> thermostat the same as the temperature sensor? If not are there >>>>> instructions on replacing it? >>>>> >>>>> Where would I get the part numbers for what I need? >>>>> >>>>> >>>>> Thanks, >>>>> Andrew |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
98 Caravan Overheating, Whining, and more | [email protected] | Chrysler | 5 | July 7th 06 05:00 AM |
Accord/Civic (probably others) overheating problems | rshpeley | Honda | 2 | May 26th 06 03:06 AM |
sudden engine overheating | [email protected] | Saturn | 15 | March 31st 06 09:42 PM |
1984 BMW 318i Overheating | MattyG | BMW | 4 | March 24th 06 12:57 PM |
overheating | sjayk58 | Technology | 4 | December 22nd 05 02:01 AM |