Over heating car

forzacalcio

Ok here is the issue.
Car has been over heating for the last two/three weeks.
I brought it to the mechanic and got the Thermostat fixed. This didnt fix the issue. Next up was the Water Pump (Got the belt changed too but this also did not fix the issue.) Ive been to 4 mechanics and they all seem to think it could be something different from Coolant sensor to Electrical problems to blocked Radiator. The fan does work.

The car overheats when mostly idle or at traffic lights and City driving. The car will peak at 100/110 degrees and go back to 90 degrees at very random intervals. Im not losing coolant and I still get hot air when I turn the heating up. Any ideas as Im really fed up of trying to get the issue resolved.

EDIT: AUDI A3 1.6litre petrol

tossy

You will get advise quicker if you list the make/model and engine.

david

It could be a blocked radiator. You could have lime deposits if you've being using tap water/antifreeze instead of proper coolant.

Easy enough to test it yourself, take off the bottom hose and see what sort of flow you get (restricted or not).

cml387

Pressure test of coolant system might show something.

forzacalcio

david wrote: »

It could be a blocked radiator. You could have lime deposits if you've being using tap water/antifreeze instead of proper coolant.

Easy enough to test it yourself, take off the bottom hose and see what sort of flow you get (restricted or not).

Yeah I think Im going to get a radiator flush next, just thought this would have been a basic check by a garage before changing pump and thermostat. I always put in proper coolant. About a year ago it needed a top up

Edit: Its actually antifreeze Ive been using I think!

forzacalcio

cml387 wrote: »

Pressure test of coolant system might show something.

What prices are we looking at here?
And are these basic checks that should be done?
Cheers for all the info lads much appreciated

forzacalcio

Anyone with any other ideas?

conamara

If you get an answer I'd love to know!!! Am in the same boat - 02 1.6 Audi A3. I have changed the thermostat, water pump, coolant temp sensor, the radiator, a suspected leaking pipe and even the cap on the coolant tank and nothing has fixed it!! Overheats randomly and seems to be losing coolant somewhere Very slowly, about 1 litre a week- but we cannot find a leak!!

Head Gasket is the next thing - but no signs of this being the problem as the engine is running perfectly and there is no gunk in the oil etc.......starting to overheat myself at the thought of it!!!

forzacalcio

conamara wrote: »

If you get an answer I'd love to know!!! Am in the same boat - 02 1.6 Audi A3. I have changed the thermostat, water pump, coolant temp sensor, the radiator, a suspected leaking pipe and even the cap on the coolant tank and nothing has fixed it!! Overheats randomly and seems to be losing coolant somewhere Very slowly, about 1 litre a week- but we cannot find a leak!!

Head Gasket is the next thing - but no signs of this being the problem as the engine is running perfectly and there is no gunk in the oil etc.......starting to overheat myself at the thought of it!!!

What I have noticed over the last few days is when I have the heating on the issue doesnt occur (When I say on I mean the knob turned to the hot part I dont actually turn up the heat) By the way mine is a 02 A3 aswell. Interesting. I was told this could also be the coolant connection. There are 4 pins in this and two go to the thermostat and two go to the Dial on my dashboard. If one goes it could cause havoc on the temp gauge. Have you ever had issues with the Over heating light coming on and beeping? EDIT: I just saw you changed this already!

conamara

Yeah changed most parts!! Yesterday was the first time it began to overheat on a shortish journey - about 35kms. It happens every time I use the motorway but as I said I am topping up the coolant weekly!

franksm

Is the fan running okay ?

I had a failed fan on one car whereby the fan was spinning but only at a low rpm - so it "looked" like it was working but wasn't. Driving the car caused air to flow through the rad, so it only started overheating when stopped in traffic.

Different car, different time: the fan wasn't working at all. I bridged the relay for the fan temporarily, but it still failed to run - so replacing the relay fixed that one.

dr.fuzzenstein

forzacalcio wrote: »

What I have noticed over the last few days is when I have the heating on the issue doesnt occur (When I say on I mean the knob turned to the hot part I dont actually turn up the heat) By the way mine is a 02 A3 aswell. Interesting. I was told this could also be the coolant connection. There are 4 pins in this and two go to the thermostat and two go to the Dial on my dashboard. If one goes it could cause havoc on the temp gauge. Have you ever had issues with the Over heating light coming on and beeping? EDIT: I just saw you changed this already!

That is because in most cars the heater matrix is very much like a mini radiator, by turning up the heat, you're turning on a tap that lets hot coolant flow into it, or opening a flap that lets cold air flow over it, thereby giving you extra cooling.

Mar4ix

Happened on other car though, but hope will help on yours. First do sniff tests... thats carbon check in coolant, usually in any garage they may check, if testing liquid from blue turns green, it is possible headgasket leak, check that at least in two different garages. If it does go green, than perform other tests, as cylinder compression tests, tools has to be right, if you not doing yourself, than do in two different garages, and compare tests. (tool cost around 20 -30 ish euro). ... also might worth is check or even change temperature sensors, i am not sure, there is one sensor which gives info to ecu and dashboards, or there is two different sensors. After those test, we can think, what to do next.
Actually once faulty dashboard sensor on one car wrecked my head , i even changed headgasket (my own car), and after that i changed temp sensor for dash(8 euro), turns old sensor was faulty.

listermint

Hi Lads,

just want to chime in here. Are you sure the car is actually overheating?
Have you had the codes read from it.

Audi have a notorious issue with the Dash Board clocks were certain things such as temperature will randomly (and sometimes) permanently display wrongly. It involves replacing the entire cluster.

This is quite evident in the TT models, not sure of impact on the A3. But i would insure that the codes are read and the sensors are checked correctly.

forzacalcio

I've gone to 4 garages, at this stage they all say sensor as the temperature can't go from 90 to 110 and back to 90 in 30 seconds in reality. The garage that changed the thermostat and water pipe have said definitely not gasket. This hasnt happened since Saturday and I have the heater on cold now and temp doesnt budge. I'm thinking more along the lines of sensor issue now which I hope I'm right. On a side note the orange light on the dahboard has come on but it's been doing that for over a year now it goes in and off randomly.

The guy who changed all the parts is off till Friday so I'm
Going to test the car and see how I get in till then!

forzacalcio

Right after three days of normal temp the car started overheating thsi morning again. Brininging it in on Friday and will do all these tests and get the coolant sensor fixed

Mar4ix

forzacalcio wrote: »

Right after three days of normal temp the car started overheating thsi morning again. Brininging it in on Friday and will do all these tests and get the coolant sensor fixed

well, you cant fix coolant sensor, just replace.

You have to do diagnostics.
Have you done ? Any faults ?
If you around blanchardstown, i can hook up to original VAG com, wont charge you, just quick look what itll say.

If heater doesnt work after coolant change and pump, could be air lock.

forzacalcio

Mar4ix wrote: »

well, you cant fix coolant sensor, just replace.

You have to do diagnostics.
Have you done ? Any faults ?
If you around blanchardstown, i can hook up to original VAG com, wont charge you, just quick look what itll say.

If heater doesnt work after coolant change and pump, could be air lock.

Down south Im afraid thanks for the offer though. The heater does work, Im getting hot air. Going to get the diagnostics checked as the orange engine light came on Sunday but is gone again but will be checking this Friday!

forzacalcio

Right so just an update on the car. Yesterday the car was overheating again so pulled into the first mechanic I saw. The guy said he would have a look and seemed to be doing alot, next thing he says I will show you why its the thermostat. I did tell him a new one was fitted 1 week ago. He took the piece out and I hear something drop. He broke the thermostat. He tries to tell me it was broken in the first place and I needed a new one. I told him yes I could have brought it back to the original garage and got a new one under warrenty. He said I can put the broken piece back in and he wouldnt knwo the difference. I spent about 40 minutes demanding he refit the part. The car was now underheating instead of over heating as the thermostat part was taken out/broken off.

He did try to say he fixed the issue but of course why is that part even there if its not needed. Anyway after a good 40 minutes of back and forth he agreed to fix the part. Part was fixed today low and behold the car is over heating again. FFS! Anyway he did note that when the temperature gauge is at 90 the readings are actually 100 on the handheld reader he plugged in. Another thing of note is the air pipe/hose that goes to the engine was broken and only an Audi garage can fix this. Does anyone know if this part would cause over heating? He said it wouldnt but I haev my suspicions.

Now when I say overheatimg it goes from 90 to 100 gto 110 and back again to 90 in the space of 1 minute!

Mar4ix

maybe worth put original Audi thermostat. and car needs to be properly bleed from air in cooling system. if air in cooling system , it will overheat. wonder, what orange warning light show up,