okay thanx for helping me fix the problem guys car has been on good temperature for a while now, untill today, i was sitting at traffic on an uphill when i noticed the temperature rise to 100 celcius from 90 which i consider over heating, i then turned on my heater full blast and the temperature went down in about 10 seconds, which i think is weird, i checked coolant level, its the same ( abit low but above minimum which is how much i had filled up so nothing is leaking).

guys? jest? what do i have here?

 

well...when you turn the blower for the heater on that it acts much like an aditional radiator fan. You have coolant flowing to the heater core and the blower motor blows air across it. Much like an electric radiator fan would. That is why your temp dropped like it did. As for the overheating issues I'm going to stay out of it. It seems anytime i suggest anything it gets sructinized by 20 people in 10min who all need to be right. I'm an ASE certified mechanic, I put up with customers all day who want to be right, so i don't really want to deal with it here too. But if I were you, I'd look into why my electric fan isn't turning on(besides the a/c request). And go....rip it apart guys

 

Yea it sounds like either the cooling fan isn't coming on because the motor is bad, or it could be a cooling fan temperature switch that's not telling the fans to turn on.

 

ah okay you could be right there dood, i noticed the electric fan isnt switching on unless i turn it on via the heater (i dont use a/c just heater which i think is the same thing) .... so where to start? how do i find most accurately what is wrong? ive got vag-com but i doubt that helps?

anyones opinion is appreciated, right or wrong....

 

Well someone better explain to me, where the water is going if it isn't leaking??? I am perplexed. If you dont have any water leaking from the bay, i'd be checking all your carpets mate. If they are wet, it could mean your heater core has sh.it itself or the drain is clogged. If, like Jest said, you don't fit the 2 gallons in just start the car and you will watch the level drop as the air bubbles are forced out.. . . . . May also be a good time to be looking for a leak.

(That plug on the bottom of the resy is just a sensor/switch I think, doesn't really control anything. . . . . I don't think)

 

Well, if the coolant is getting lower it is leaking either into the engine, or outside of the engine.

Check for "Cafe au lait" oil emuslion either on the dipstick or under the oil filler cap (big leak into cylinder).

check for small leaks under the car and cracks in the plastic reservoir. Check the oil cooler (where the oil filter mounts), If there is buildup of pink efflourescence (crud), the hose clamps are allowing coolant to seep out.

 

hello everyone!, i have a 1998 Audi A4 2.8 Q and just yesterday it started to run a little hot but not overheating, its about 3/4 or just under while driving and will not go any hotter.. i just had the water pump, belts, pulleys, Anti-frez replaced, a year ago i was told it might be the Thermostat going? does anyone have any ideas in what could cause this to happen?

 

great it overheated again just a little bit, and as soon as i turn heat on full bolt it cools down, now the thing is, when i turn a/c on (cold) it doesnt cool down? only when heat is on full bolt (just fan no a/c)... so im thinking it cant be the fan because the fan is turning on as soon as i tell it to... could it be something failing to tell the fan that the car is over heating? i have vag com, is that going to be of any help to diagnose the problem?

 

I think you are confused between the two fans being talked about. the one fan that I think your refering to is in the dash and actualy blows air out of the vents in your dash. this fan will help with the cooling if the temp is selected to hot. the other fan is under the hood right behind the radiator. It has two speeds when you turn the A/c on this fan should turn on high and be noticable from outside the car. one prob with runing the a/c and a reason that it wont help to get that outside fan going is cus you also turn on the a/c system. if you feel the condenser that is mounted infront of the radiator when the a/c is on (snow flake on the a/c controler) you will notice that one side of it gets very hot. the air going to the radiator will have allready been heated some by this. I just changed my fan temp switch (located back leftside of the radiator) to the 160 that you can find on www.ecs-tuning.com and it works well, even turns the fan on high without the use of the a/c. hope this helps some.

 

the coolant is designed for the audi ALUMINUM engine block, regual coolant/antfreeze will corrode and block off the journals inside the block and that costs money