Hi All,

I have an audi a4 2008 model 2.0 l car. Whenever I am idling my engine overheats and the aircon does not blow cool air. The CTS sensors, thermostat and the fan control module have been replaced, the fans dont seem to be running fast enough for the engine to cool down enough. When connected directly to a power source, both the fans turn pretty fast and my aircon and engine behave as they are supposed to.

When we connect the OBD we get an error p1530, something about the camshaft being short circuit but this error varies.

There is another error of high pressure which we get when we query the HVAC system.
i am afraid i dont have the codes for this error.

Pls help cos I have had the car at the garage for the last week and me and the expert are at our wit's send and can't find answers

 

It is fairly common for the CTS sensor and/or temp gauge in the cabin to be incorrect... The needle could be showing that your overheating when you really aren't.

The radiator fans and the engine's computer work off of different sensors... There is s "coolant temp sensor" for the engines computer and a "coolant temp switch" for the fans..

The most common causes of overheating are 1) low coolant level 2) thermostat 3) faulty water pump 4) insufficient fan speed.

Your car should have a coolant level sensor, but be sue to check it manually just incase.

Be sure you replaced the correct temp sensor (it should have a black electric connector)

Be sure the thermostat is opening when it should.. (You should be able to put your hand on the coolant line the the radiator and feel the pressure/head when the thermostat opens)

A little while after the thermostat opens the fans should start kicking on..


Let me know what you find..

 

Thanks for the update CryptoStorm.

Coolant level, thermostat and faulty water pump can be ruled out as they have all been checked. The problem is essentially insufficient fan speed. this is what we are trying to understand. When fans are given power directly they run at good speeds causing the aircon to start cooling and the engine to work at around 90 degree Celsius. The fan control unit and temperature sensor along-with thermostat have been replaced and checked if they are working as they should adn we havent found problems with them. I'll keep you posted on further investigation.

We are trying to get both the fans and its housing from the scrap market and check to see if it is working properly.

 

Well its not an 88 Ford .. Its a variable speed fan.. What temperature does it get up to if youre not running direct voltage?

 

It goes upto the midpoint between 90degrees and maximum and on occasion if i dont switch off the car, it has gone beyond, typically the coolant starts boiling when this happens

 

Have you checked your fuses up by your battery?