Heat Goes Up When The Ac Is On

cefiroA33 · April 18, 2016

Hi guys. Wishing everyone a prosperous and peaceful new year. I have a issue in my second car Nissan Bluebird SU14 1999 diesel model. I have noticed that heat goes up after running 7 or 8 km with AC on. Going in to more details during the mornings and evenings generally the AC indicator is in 1 position heat never goes up. But during the noon when 1 is not enough due to heavy heat in the atmosphere, and the AC is on 2 vehicle heat going up within 7-8 km run. This distance declines with the AC position going further up. I have checked applying some night speed water jet to the condenser to clean it but the heat still goes up. Can anyone help me on this regard? Thanks.

fiatLife · April 18, 2016

Hi cefiroA33, wishing you the same.

In the noon time it can be sort of accepted because of the atmosphere heat. Does the engine heat gauge go above the halfway mark? Are you using coolant/water? Maybe check the thermostat? it could be blocked which results in the coolant/water flow being restricted...

jayanathkarunarathna · April 18, 2016

I had similar issue in my Suzuki Swift due to an issue in AC fan. It was not original fan and petals were shorter than original. after replacing fan with lengthy petals issue was fixed.

cefiroA33 · April 18, 2016

Hi guys I checked with a mechanic and he said the thermostat valve has been removed. Also I am using coolant instead of water. Heat gauge goes well above the half way mark but as soon as the AC is turned off it drops to the half. Anyways I sent the radiator to be cleaned to check whether it is due to any block in the radiator.

fiatLife · April 18, 2016

keep us updated

Twin Turbo · April 18, 2016

Wishing you the Same.

Engines running hot and over heating can be caused by a number of contributory factors,.. and yes internal blockages of the cooling system can cause the engine to run hot.

Have you checked the operation of cooling fans with the A/c on?the increase in blower speed cannot be directly linked to the engine over heating , but would cause the system to work for longer causing greater strain on the cooling system which having an issue an is now showing it by overheating.the engine

Cleaning the condensir with pressurised water should be carefully done as it may cause bent cooling fins blocking air flow leading to even more overheating.

Getting this fixed immediately before it leads to costly head-aches should be a top priority.

TT.

P.s. This car is 17 years old. how is the engine's compression / mileage? this may be your engine asking for a rebuild. To get the best performance from the A/c., I have got my side windows and rear windscreen tinted, and always keep the fresh air vent firmly closed.

Edited April 19, 2016 by Twin Turbo

Rumesh88 · April 19, 2016

Hi guys I checked with a mechanic and he said the thermostat valve has been removed. Also I am using coolant instead of water. Heat gauge goes well above the half way mark but as soon as the AC is turned off it drops to the half. Anyways I sent the radiator to be cleaned to check whether it is due to any block in the radiator.

It is possible that this engine has a history of overheating. In addition to the things others have mentioned above check the water pump as well particularly if that it has not been recently (say within last five years) replaced. Also check if the pressure inside the coolant system is at the proper level ie cap is sealed (and rated for something like 127kpa) and no cracks/leaks in the tank/core/hose etc however minor it is.

cefiroA33 · June 3, 2016

Hi guys!!

Sorry for delay in responding. The issue was sorted and as rumesh correctly said it was the water pump that created the issue. Due to the use of water instead of the coolant, water pump has been damaged severely. once it was replaced with a new pump heating issue disappeared. Purchase the water pump from Pi_ne__r motors panchikawatta and they were surprised that issue was identified correctly soo soon. speacial thanks to Rumesh88 for this.

Regards,