Overheat in my 1997 volvo s40

Buriya2112 · Post by **Buriya2112** » 20 Oct 2018, 01:06

Hi, I am Buriya from Cameroon in Central Africa. I have this cool Manual, 1997 volvo s40 , 16 valve turbo engine manufactured in the Nederlands which I love so much but I have a problem with the temperature guage. As a matter of fact, I am kind of confused because it has a digital guage.

I wish to find out first if the temperature reads in Celsius or farenheit.

Secondly, my thermostat broke and my mechanic removed it and told me that the car can work perfectly well without one. I don't know if that is true and if no, what's the effect on my cAR running without a thermostat?

I equally want to know the normal operating temperature of a volvo s40 1997 model. When I start my car in the morning, the guage reads cold but after the engine runs for say 30 seconds to a minute, it changes to 44 degrees and then starts to increase gradually.

The fan sets in when the temperature goes up to 116 degrees and after running for like 20 to 30 seconds or more sometimes, it goes down to 108 degrees and sometimes 106 degrees depending on the temperature outside, and then it climbs again and the process continues. That happens mostly when I drive around town or in the neighborhood. But on the high way or when the AC is on, the temprature operates between 84 and 90 degrees max.

The over heat alarm which I have seen just once since I bought the car three years ago sets in when the temperature guage goes up to 121 degrees.

Most often since I drive only within.my city and in my neighborhood, the temperature fluctuates between 106 degrees to 116 when the fans set in. But when driving on the highway, the temperature fluctuates between 82 and 90 degrees depending on the speed. Same thing when the AC is turned on. I want to believe,this is as a result of the high airflow.

I just wish to.find out if that temperature reading is ok becuase my country is a hot country. I am equally.the only one.in.my city.with the car, so when the car has a problem I have to buy the parts online and have them shipped to me either from the US or Nigeria.

Will appreciate your feedback.

Buriya2112 · Post by **Buriya2112** » 20 Oct 2018, 01:11

I will appreciate all feedbacks.

Post by **alschnertz** » 20 Oct 2018, 18:31

Buriya2112 wrote: ↑20 Oct 2018, 01:06As a matter of fact, I am kind of confused because it has a digital guage. I wish to find out first if the temperature reads in Celsius or farenheit.

Secondly, my thermostat broke and my mechanic removed it and told me that the car can work perfectly well without one. I don't know if that is true and if no, what's the effect on my cAR running without a thermostat?

I equally want to know the normal operating temperature of a volvo s40 1997 model. When I start my car in the morning, the guage reads cold but after the engine runs for say 30 seconds to a minute, it changes to 44 degrees and then starts to increase gradually.

The fan sets in when the temperature goes up to 116 degrees and after running for like 20 to 30 seconds or more sometimes, it goes down to 108 degrees and sometimes 106 degrees depending on the temperature outside, and then it climbs again and the process continues. That happens mostly when I drive around town or in the neighborhood. But on the high way or when the AC is on, the temprature operates between 84 and 90 degrees max.

The over heat alarm which I have seen just once since I bought the car three years ago sets in when the temperature guage goes up to 121 degrees.

Most often since I drive only within.my city and in my neighborhood, the temperature fluctuates between 106 degrees to 116 when the fans set in. But when driving on the highway, the temperature fluctuates between 82 and 90 degrees depending on the speed. Same thing when the AC is turned on. I want to believe,this is as a result of the high airflow.

I just wish to.find out if that temperature reading is ok becuase my country is a hot country. I am equally.the only one.in.my city.with the car, so when the car has a problem I have to buy the parts online and have them shipped to me either from the US or Nigeria.

Will appreciate your feedback.

I wouldn't consider myself an expert on S40s, but I have wrenched on my 2001 over the past 10+/- years.

I don't know anything about a digital engine temperature gauge in an S40, and don't recall threads about same. I suspect you are referring to an aftermarket gauge. Obviously, I'd have no idea if it reads in C or F.

I do not agree with your mechanic that the car will run "perfectly well" without a thermostat installed. The engine was designed to use a thermostat to regulate engine temperature to certain parameters. It cannot do that with the thermostat removed. The engine's computer expects certain conditions and those conditions will not be met if a thermostat is not regulating the engine temperature.

I am not sure what the proper operating temperature of a 1997 model is. The S40 did not show up in North America until 2000.
90 degrees Celsius is about 194 Fahrenheit. That sounds about right for a normal operating temperature. Though I'm surprised you get to that temperature without a thermostat installed. 116 degrees C is about 240 degrees F. I would consider that the highest temp. I'd be comfortable with.

Post by **RickHaleParker** » 20 Oct 2018, 21:45

Without a thermostat there is no temperature regulation ... you should expect the temperature to be all over the place.

On the old electro-mechanical car you could be away with pulling the thermostat. The computers on the newer cars make decisions base on the engine temperature, put a new thermostat in, doing so can spare you the trouble and expense of a misdiagnosis.

difflock54 · Post by **difflock54** » 27 Oct 2018, 02:04

The radiator fan cuts in on my 2002 V40 when the temp reaches about 103-105 degrees C.
Normal highway temp is around 79 - 85 degrees.Temps will increase of course in slow traffic or idling at traffic lights etc.
Eventually the fan will cut in as stated above as it rises but the fan will only run for 20 - 30 seconds which will push the temp down to around about 95.
Not having a thermostat is not wise as the guys have already said in their responses but you can probably also include poor fuel economy as an extra issue.
I advise you to fit a new thermostat asap and also check the condition of the coolant as that allows a higher boiling point for the coolant. (50/50 mixture ratio.)
Volvo's can overheat very fast and blown head gaskets or engine seizing risks are high'
I have an 'Ultra gauge' installed in my car which displays actually engine temps in degrees C or F as opposed to the dash temp gauges which go with little warning from normal to high in mere seconds if something goes wrong. It connects to the OBD11 port and gives other useful data also.