Suzuki swift HT51S overheating issue

mjayanath · April 4, 2017

The temperature gauge needle is at the center when I'm in a highway but the needle moves up a bit and comes back to center when i'm driving uphill. I tried to replace the Thermostat valve but there is no Thermostat valve installed. My technician says there is nothing to worry. Your valuable comments are welcome.

Twin Turbo · April 4, 2017

Good thing you noticed the slight over heating

The T.valve may have been removed to 'fix' an over heating issue by a previous owner.

try checking the car with the engine nd a/c on to see weather the cooling fan properly works? and clean the coolingg fan fins from any dust/debree blockingg it. (air goingthrough the rad )

0

Edited April 4, 2017 by Twin Turbo

PerfMad · April 4, 2017

On 4/4/2017 at 9:55 AM, mjayanath said:

The temperature gauge needle is at the center when I'm in a highway but the needle moves up a bit and comes back to center when i'm driving uphill. I tried to replace the Thermostat valve but there is no Thermostat valve installed. My technician says there is nothing to worry. Your valuable comments are welcome.

Expand

Yes as @Twin Turbo mentioned get your cooling fan speeds, fuse/relays checked and radiator cleaned if its blocked

Rumesh88 · April 4, 2017

..and after verifying the cooling system get the thermostat installed particularly if you are using the car regularly for short runs.

mjayanath · April 6, 2017

Thank you so much all for your valuable comments. Two friends of mine have the same car (2004 model) and surprisingly both have the same problem. They are still trying to solve the issue.

I have recently fixed a good reconditioned radiator since there was a small leak.

I suspected Engine Coolant Temperature Sensor as everything else is ok. Replaced the ECT sensor with a genuine one (Rs.6500) few days back. I shall let you know the progress.....

PerfMad · April 6, 2017

On 4/6/2017 at 4:17 AM, mjayanath said:

Thank you so much all for your valuable comments. Two friends of mine have the same car (2004 model) and surprisingly both have the same problem. They are still trying to solve the issue.

I have recently fixed a good reconditioned radiator since there was a small leak.

I suspected Engine Coolant Temperature Sensor as everything else is ok. Replaced the ECT sensor with a genuine one (Rs.6500) few days back. I shall let you know the progress.....

Expand

Great. keep us posted

mjayanath · April 13, 2017

After replacing the ECT sensor & the Thermostat, the temperature gauge needle stays at the center without A/C. But the needle moves up at slow speeds with A/C on.

Please let me know how to check the radiator fan speeds?

asanka_rg · April 17, 2017

Hi I had the same issue (HT51s) and if u search the forum you get a good idea as well. I checked radiator for leakages and all but finally it was the fan starting temperature. So it was the thermo switch / coolant sensor. I replaced the sensor and temp gauge is steady as a rock.

mjayanath · April 17, 2017

I

On 4/17/2017 at 5:15 AM, asanka_rg said:

Hi I had the same issue (HT51s) and if u search the forum you get a good idea as well. I checked radiator for leakages and all but finally it was the fan starting temperature. So it was the thermo switch / coolant sensor. I replaced the sensor and temp gauge is steady as a rock.

Expand

I replaced the Coolant sensor too. Radiator fan switches on as soon as the needle reaches the center. But still overheats in a traffic jam with A/C on.

The Don · April 17, 2017

The HT51s has only one radiator fan. It operates at 2 speeds. Low with no AC and High with AC. The fan motor and fins are notorious for failure. One of the first things to check is to see if the dual speed operation performs as should and the fan moves freely without any interference. If there is a problem replace with used unit. This is a very typical failure unfortunately. Used to cost about 15k

Second issue to check is the water pump. If the water pump hasn't been changed recently that is something to check. But most importantly check if it moved properly without slipping on the belt. This is another HT51s problem.

Last check if the radiator is clean and get it cleaned if you suspect anything. It doesn't cost much and get it done by a radiator repair shop.

And as others have suggested replace the missing thermostatic valve with an original replacement. It's there for a reason.

mjayanath · April 18, 2017

On 4/17/2017 at 6:09 PM, The Don said:

The HT51s has only one radiator fan. It operates at 2 speeds. Low with no AC and High with AC. The fan motor and fins are notorious for failure. One of the first things to check is to see if the dual speed operation performs as should and the fan moves freely without any interference. If there is a problem replace with used unit. This is a very typical failure unfortunately. Used to cost about 15k

Second issue to check is the water pump. If the water pump hasn't been changed recently that is something to check. But most importantly check if it moved properly without slipping on the belt. This is another HT51s problem.

Last check if the radiator is clean and get it cleaned if you suspect anything. It doesn't cost much and get it done by a radiator repair shop.

And as others have suggested replace the missing thermostatic valve with an original replacement. It's there for a reason.

Expand

Former owner too has noticed the overheating and has flushed the system with a radiator flush. He was running the car with a leaking radiator. As soon as I bought the car four monts back, I replaced the radiator with a good cleaned reconditioned one as the radiator was leaking. Added the Wurth green coolant as well. No sign of rust.

There was no Thermostat valve in position. As you suggested I have installed a genuine Thermostat valve two weeks ago. Now the fuel consumption is satisfactory.

Earlier the radiator fan started when the Temperature needle is above the halfway mark (without A/C, No Thermostat). After replacing the Coolant sensor with a genuine one and a Thermostat, the fan starts when needle is just below the halfway mark (without A/C, ). Only problem is overheating with A/C on and at low speeds.

Thank you for your valuable suggestions. I shall visit a good auto electrician and check the fan speeds.

I noticed the coolant overflow reservoir is one inch above "full" mark, when the engine is at working temperature. Does it mean the water pump is working properly?

The Don · April 24, 2017

On 4/18/2017 at 3:59 PM, mjayanath said:

Former owner too has noticed the overheating and has flushed the system with a radiator flush. He was running the car with a leaking radiator. As soon as I bought the car four monts back, I replaced the radiator with a good cleaned reconditioned one as the radiator was leaking. Added the Wurth green coolant as well. No sign of rust.

There was no Thermostat valve in position. As you suggested I have installed a genuine Thermostat valve two weeks ago. Now the fuel consumption is satisfactory.

Earlier the radiator fan started when the Temperature needle is above the halfway mark (without A/C, No Thermostat). After replacing the Coolant sensor with a genuine one and a Thermostat, the fan starts when needle is just below the halfway mark (without A/C, ). Only problem is overheating with A/C on and at low speeds.

Thank you for your valuable suggestions. I shall visit a good auto electrician and check the fan speeds.

I noticed the coolant overflow reservoir is one inch above "full" mark, when the engine is at working temperature. Does it mean the water pump is working properly?

Expand

The coolant resovoir tank under normal circumstances should be fairly empty. It is really an overflow tank. When fluid expands in the heat it goes into the resovoir and then back after the fluid cools down.

I think you should empty the resovoir a little.

Also check the radiator cap. They aren't expensive and I suggest you buy a new one from the agent. It could be letting fluid into the resovoir prematurely.

I had over heating issues in our car as well. The causes were the fan (which was failing for a long time and suddenly the fin came off from the motor head) and water pump belt which keeps failing. Replacing the fan solved the first issue though we have had to keep an eye on the belt.

This fan is a known weak point in this car. Due to space constraints only one fan is used and it has to take a lot of strain.

It was the air conditioning shop which noticed the fan issue in our case.

mjayanath · April 25, 2017

On 4/24/2017 at 7:52 AM, The Don said:

The coolant resovoir tank under normal circumstances should be fairly empty. It is really an overflow tank. When fluid expands in the heat it goes into the resovoir and then back after the fluid cools down.

I think you should empty the resovoir a little.

Also check the radiator cap. They aren't expensive and I suggest you buy a new one from the agent. It could be letting fluid into the resovoir prematurely.

I had over heating issues in our car as well. The causes were the fan (which was failing for a long time and suddenly the fin came off from the motor head) and water pump belt which keeps failing. Replacing the fan solved the first issue though we have had to keep an eye on the belt.

This fan is a known weak point in this car. Due to space constraints only one fan is used and it has to take a lot of strain.

It was the air conditioning shop which noticed the fan issue in our case.

Expand

Radiator cap is a reconditioned good one brought recently.

I did my major repairs at a famous large repair shop at Karugastota. (Up to last Saturday they did a good job). Last Saturday I took my car there and tried to repair the fan motor. Unfortunately while cleaning the motor,the magnets we also removed and had to replace the fan motor with a new one cost me Rs.7000. While fixing the fan the technician damaged the radiator and took me two hours to find a fairly good radiator (cost Rs.10000, cost reimbursed). Lost my good radiator although replaced+ Wurth coolant. Hell.....

Another famous electrician in front of Katugastota police station suggested that a fan is fixed in front of the A/C condenser, but I refused. I guess it might block air passage when the A/C is off. Any comment on this please......

I'll let you know the progress later....

mjayanath · May 3, 2017

Now the temperature needle stays at the center. Seems like the problem has been solved after replacing the fan motor. Thank you guys for your valuable comments.

wild in_the_wild_expeditions · March 24, 2022

Hey guys i just want to know when im using my swift 2003 it overheats without the ac when i use the ac it dosnt overheat and in high hills it tend to overheat. If i turn off the ac temp gauge goes up like a bullet.pls help me..

iRage · March 25, 2022

On 3/24/2022 at 2:44 PM, wild in_the_wild_expeditions said:

Hey guys i just want to know when im using my swift 2003 it overheats without the ac when i use the ac it dosnt overheat and in high hills it tend to overheat. If i turn off the ac temp gauge goes up like a bullet.pls help me..

Expand

How is the general condition of your car ? Are you observing any smoke ? bubbles in the radiator ? oil in the radiotor ? rust in the radiator ? Leaks around hoses, radiator, radiaor cap, gaskets, etc... ? Are your fans working ? Is their a loss in coolant fluid levels ?

THIS IS PURE SPECULATION AT THIS POINT....

You might have a general engine cooling issue (perhaps at an early stage) where when the AC is turned on the fan kicks in more regularly/frequenty and for a longer period of time that it manages to cool down the engine again under normal conditions. However, when the car is under a heavy load (climbing up hill, going fast, carrying a load where the engine needs to rev higher) the extra work of the fan cannot compensate for cooling down the engine.

Edited March 25, 2022 by iRage