Engine heat goes up in traffic driving

asanka_rg · January 22, 2017

hello everyone,

I recently bought a 2003 Suzuki swift jeep model. I have noticed a heat indicator going above the middle mark (3/4) but it went down in few minutes. Moreover I drived in Katunayaka highway and heat indicator was on and below middle mark or the heat gauge.

I doubt that radiator got some blocks and i flushed and refill the coolant. But the same issue is still there. Is this a bad thermostat or give me some advice on this will be highly appreciated.

Twin Turbo · February 11, 2017

Replase the thermo switch

Edited February 11, 2017 by Twin Turbo

Rumesh88 · February 11, 2017

On 2/11/2017 at 3:58 AM, asanka_rg said:

I met an auto electrical guy and check the fan. Fan is working in both speeds.

then I checked the fan starting temp without ac. It's 98celcius (coolant temp). At that point the heat gauge is above the middle.

is that fan starting temp is correct ? (thermostat temp rating was 82 celcius)

what should I do as per the above readings.

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If you read the above figure (98 C) through OBD port then you may have a problem with the ECT sensor (I said "may" because on the other hand your gauge could be inaccurate). For all what I know the fan starts at 97.5C at slow speed and switches to high speed at 102.5C. If you read a figure of 98C through OBD port then your ECU is doing its job by starting the fan at the right apparent temperature but by then if the gauge goes above half mark then actual coolant temperature may be a couple of degrees above 98C assuming the gauge is correct. I hope you get what I mean here.

Edited February 11, 2017 by Rumesh88

Davy · January 22, 2017

Could be that the radiator cooling fans aren't working. Start the car, switch on the AC and wait until the temperature gauge reaches mid point. After a couple of minutes, you should see the fan(s) start to work. Not sure about the Swift, but on some cars, the fan(s) start to work as soon as the AC is switched on, regardless of whether the engine is warm or not.

If the fans(s) is/are not working, it could be due to a faulty fan or the fan control module.

Twin Turbo · January 22, 2017

Could be it's time to replace your thermostat valve. Get your water pump checked. and properly bleed the cooling system with the heater on.

Most important, is the car leaking any coolant?

Edited February 9, 2017 by Twin Turbo

GayanR · January 22, 2017

water pump gone

asanka_rg · January 22, 2017

fan is working fine. And I have flushed the radiator with some chemical and refilled the coolant?. No idea about the pump anyway

jayanathkarunarathna · January 22, 2017

On 1/22/2017 at 12:15 PM, asanka_rg said:

fan is working fine. And I have flushed the radiator with some chemical and refilled the coolant?. No idea about the pump anyway

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Check whether your radiator fan is the correct one. May be previous owner replaced it with an incorrect fan. I had exact issue in my 2003 swift after I replaced my radiator fan. Replaced fan blades were nearly 2 inch shorter than original fan blades. Issue was fixed once I replaced with a fan with correct length blades.

TheClutch · January 22, 2017

It's the fan.. Check the fan for issues said in above post.check the blowing direction too

Edited January 22, 2017 by TheClutch

asanka_rg · January 24, 2017

thanks you all for the reply I'll check things u guys mentioned and get back here

jayanathkarunarathna · January 24, 2017

On 1/24/2017 at 6:17 AM, asanka_rg said:

thanks you all for the reply I'll check things u guys mentioned and get back here

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Forgot to say. Check your fan is working in both speeds. Faulty relay might stop working your fan in high speed.

asanka_rg · January 30, 2017

hi guys,

I have check the fan. fan is turned on when the heat mark close to the middle. (without AC)

fan blades are also very close to the fan frame. fan wires can not be exchanged since the fan socket is made to fit it in the right way.

Anyway I have changed the thermostat and I will update whether it is fixed or not? thanks

asanka_rg · February 8, 2017

Hi guys,

I changed the thermostat and drove around but I see once the indicator going 3/4 of the gauge only when driving up a steep road. I see the root cause is not yet fixed here. would anybody help to conclude the root issue here ?

thanks

asanka_rg · February 8, 2017

On 1/22/2017 at 11:24 AM, Davy said:

Could be that the radiator cooling fans aren't working. Start the car, switch on the AC and wait until the temperature gauge reaches mid point. After a couple of minutes, you should see the fan(s) start to work. Not sure about the Swift, but on some cars, the fan(s) start to work as soon as the AC is switched on, regardless of whether the engine is warm or not.

If the fans(s) is/are not working, it could be due to a faulty fan or the fan control module.

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fan is starting at the mid point of temp indicator (with out AC) if AC is on fan is always on. fan blades are also original.

what other causes make this anyway??

asanka_rg · February 8, 2017

On 1/22/2017 at 11:34 AM, Twin Turbo said:

Could be it's time to replace your thermostat valve. Get your water pump checked. and properly bleed the cooling system withe heater on.

Most important, is the car leaking any coolant?

Expand

I never bleed the cooling system. no coolant leak

I asked the mechanic and he mentioned that do not need to bleed !!?? could you explain bit more the words "bleed the cooling system while heater on"

jayanathkarunarathna · February 8, 2017

On 2/8/2017 at 7:32 AM, asanka_rg said:

fan is starting at the mid point of temp indicator (with out AC) if AC is on fan is always on. fan blades are also original.

what other causes make this anyway??

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Fan is not always on even with A/C. Fan goes off when cabin is cooled. Is your AC system fine?

Davy · February 8, 2017

On 2/8/2017 at 7:32 AM, asanka_rg said:

fan is starting at the mid point of temp indicator (with out AC) if AC is on fan is always on. fan blades are also original.

what other causes make this anyway??

Expand

You shouldn't have replaced the thermostat verifying the simple things first. Did you buy the correct replacement thermostat? Remember that thermostats have a temperature rating. If you put in one that is rated higher than your original one, it will not open at the right time and the engine will run a bit warmer. Anyway, since you have already done it, that's that.

1. If you have dual speed fans, make sure they work at the high speed as well as low speed. You should feel a strong flow of air when the fan operates at high speed.

2. It could be due to a clogged radiator. Especially if you use water instead of coolant. Any radiator shop should be able to clean the radiator for you. The process involves taking the radiator out of the car, disassembling the top and bottom tanks and cleaning each water line in the core to make sure that none of them have any blockages. You should have done this while replacing the thermostat IMO.

3. While the engine is cold, carefully remove the radiator cap, start the engine and let it reach operating temperature. While gently revving the engine, observe the flow of coolant through the radiator filler neck. You should see coolant flowing in one direction and the flow rate change based on the RPM of the engine. If the coolant look stagnated, then it could be that your water pump is busted. This is a bit of a complex repair, so be absolutely sure that all other possibilities are eliminated.

4. Air trapped inside the cooling system can cause the temp gauge to go up when going uphill. Since you replaced the thermostat, there is the likelihood of air being trapped in the system. The air needs to be bled out of the system. The procedure is pretty straight forward, and you can do this at home. Watch the video below and you will understand:

Edited February 8, 2017 by Davy
Corrected duplicated content.

Rumesh88 · February 8, 2017

To me it looks like your duel speed radiator fan is not switching to high speed as mentioned above by Davy. Is your radiator fan a two wire one or a four wire one?

Edited February 8, 2017 by Rumesh88

mahesh9100 · February 9, 2017

Same thing happened to me few months back. Radiator fan and coolant level were also fine.But the issue was the tube which used to flow the coolant from the coolant tank was misplaced. After fixing it my problem was solved.

Twin Turbo · February 9, 2017

Don't drive with an over heating condition as it can lead to big head aches,..

TT.

Edited February 9, 2017 by Twin Turbo

jayanathkarunarathna · February 9, 2017

On 2/8/2017 at 11:41 AM, Rumesh88 said:

To me it looks like your duel speed radiator fan is not switching to high speed as mentioned above by Davy. Is your radiator fan a two wire one or a four wire one?

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If it is Original. Fan is dual speed

asanka_rg · February 9, 2017

On 2/8/2017 at 11:41 AM, Rumesh88 said:

To me it looks like your duel speed radiator fan is not switching to high speed as mentioned above by Davy. Is your radiator fan a two wire one or a four wire one?

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it's four wire fan

Rumesh88 · February 9, 2017

On 2/9/2017 at 4:47 AM, asanka_rg said:

it's four wire fan

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Then keep a note of the fan speed (better with AC off so that you get only the noise of radiator fan) when it first kick in. Then when the heat goes to 3/4 pull the car over to a side without stopping the engine and observe the radiator fan with AC off. You should be able to clearly see the fan running at a higher speed than before.

Edit: Another thing you can observe at the same time is to switch off the engine and see if the fan continues to run for a while. AFAIK this feature is activated only when the ECU detects a high temp situation. This observation will help in determining if ECU actually detects the high temperature or not.

Edited February 9, 2017 by Rumesh88

asanka_rg · February 9, 2017

On 2/8/2017 at 9:12 AM, Davy said:

You shouldn't have replaced the thermostat verifying the simple things first. Did you buy the correct replacement thermostat? Remember that thermostats have a temperature rating. If you put in one that is rated higher than your original one, it will not open at the right time and the engine will run a bit warmer. Anyway, since you have already done it, that's that.

1. If you have dual speed fans, make sure they work at the high speed as well as low speed. You should feel a strong flow of air when the fan operates at high speed.

2. It could be due to a clogged radiator. Especially if you use water instead of coolant. Any radiator shop should be able to clean the radiator for you. The process involves taking the radiator out of the car, disassembling the top and bottom tanks and cleaning each water line in the core to make sure that none of them have any blockages. You should have done this while replacing the thermostat IMO.

3. While the engine is cold, carefully remove the radiator cap, start the engine and let it reach operating temperature. While gently revving the engine, observe the flow of coolant through the radiator filler neck. You should see coolant flowing in one direction and the flow rate change based on the RPM of the engine. If the coolant look stagnated, then it could be that your water pump is busted. This is a bit of a complex repair, so be absolutely sure that all other possibilities are eliminated.

4. Air trapped inside the cooling system can cause the temp gauge to go up when going uphill. Since you replaced the thermostat, there is the likelihood of air being trapped in the system. The air needs to be bled out of the system. The procedure is pretty straight forward, and you can do this at home. Watch the video below and you will understand:

Expand

Thank you for the elaboration. first thing I'll bleed the cooling system and i'll checked the fan operation in two speeds. Then I determine whether to clean the radiator or not? themostat should be fine as I replaced as per the OEM part no.