Temp gauge advice

[Steve_D]

Hi folks, just trying to get a bit of help with my temp sensor... I have an Audi A4 B5 1999 Treg Saloon 1.8 non turbo 5V and its petrol (think thats everything lol)

Basically is the Dial on the temp gauge suppose to be at 90 deg and stay at 90 deg even when your driving?

If i stay still and dont have the heaters on it will rise to 90 and stay there, go no further (good thing) but when i drive it goes down gradually and read at it lowest point as if the engine is switched off within about 10 - 20 mins, the same if i put warm air into the car

Now in my experience isn't it suppose to stay reading 90deg Celsius wether the car is standing still or moving? i can probably understand if it dropped because i had the eaters on MAX and full fan speed

Can anyone shed any light on this for me as its bugging me a bit now...

I do get hot air.. very hot

but if the temp gauge is below 90 doesn't the ecu tell the engine its cold and runs more fuel to (try) get it hotter?

This had been bugging me for a few years now, would changing the thermostat solve the problem?

 

[ex911driver]

Sounds like Thermostat to me, buy a Genuine Audi one as non gen never seem to last very long.

 

[hades-]

ill 2nd it been the stat

 

[Steve_D]

cheers guys, i'll visit stoke audi for that then, dont like the cheep chat stuff myself.

Best / easiest way to do the job? and the refil of the coolant after... just pour it in with the engine running?

hate taking it to garages only for MOT's lol.. do the rest myself

 

[Steve_D]

£28 for a genuine thermostat.. was expecting that. Thats my days off sorted, as well as sorting out the dead pixels in my Dash LCD lol

 

[aragorn]

dont pour it in with the engine running!

To remove the stat follow the lower rad hose to the water pump housing, the stat is under the black plastic elbow.

I find the best way to do it, is to remove the hose from the elbow first, then take the elbow off. Reason being, refitting is a bit of a balencing act, trying to get the stat and seal up into the housing and the elbow back on, and its easier if the hose isnt attached and in the way.

Once its fitted and the pipe reattached, pour in 2.5L of neat antifreeze (red stuff) then remove the heater hose with the hole in such that the pipes still fitted, but the hole is exposed. Give it 5 mins, then pour in plain water. You'll need approx another 2.5L, and you'll find that if you fill the expansion tank and leave it a few mins the level will drop and you can fit more in. Repeat this until it stops dropping, and if you squeeze the top rad hose you should get a little spurt of water out the hole in the heater pipe.

Refit the heater pipe, attach the reservoir cap and go for a drive round the block to get the car upto 90. If you have climate control, use the diagnostic mode to view the actual temperature, and make sure it comes up to 90-92. Return home and check round the bay for leaks, and ensure the level is still correct. If its all good, take it for a longer drive and make sure the temperature does what it should.

 

[Steve_D]

dont pour it in with the engine running!

To remove the stat follow the lower rad hose to the water pump housing, the stat is under the black plastic elbow.

I find the best way to do it, is to remove the hose from the elbow first, then take the elbow off. Reason being, refitting is a bit of a balencing act, trying to get the stat and seal up into the housing and the elbow back on, and its easier if the hose isnt attached and in the way.

Once its fitted and the pipe reattached, pour in 2.5L of neat antifreeze (red stuff) then remove the heater hose with the hole in such that the pipes still fitted, but the hole is exposed. Give it 5 mins, then pour in plain water. You'll need approx another 2.5L, and you'll find that if you fill the expansion tank and leave it a few mins the level will drop and you can fit more in. Repeat this until it stops dropping, and if you squeeze the top rad hose you should get a little spurt of water out the hole in the heater pipe.

Refit the heater pipe, attach the reservoir cap and go for a drive round the block to get the car upto 90. If you have climate control, use the diagnostic mode to view the actual temperature, and make sure it comes up to 90-92. Return home and check round the bay for leaks, and ensure the level is still correct. If its all good, take it for a longer drive and make sure the temperature does what it should.

Cheers for that aragorn, simple and sweet info. Their is a coolant / antifreeze mix in halfrauds, is that any good? 5ltrs it is

Halfords | Halfords Ready Mixed Antifreeze & Coolant 5 Litres

or just stick to the normal antifreeze and tap water?

 

[hades-]

get the proper red vag stuff

 

[Steve_D]

get the proper red vag stuff

got any links to it? so i can see what im going to get? or do you just mean proper stuff by the colour and not a make?

 

[aragorn]

He means goto Audi/VW dealer and buy the coolant from them. If you have one nearby its worth pricing up as sometimes they're fairly competitive. You'll need two bottles though, as it comes in 1.5L containers, and you need about 3L of concentrate.

Personally i just buy generic "long life" red coolant from my local motorfactors. You must use the red stuff, normal blue antifreeze isnt advised.

Not that the halfords stuff is bad, its just overpriced. They're selling a gallon of ready mixed for £20, whereas a gallon of concentrate from the factors is typically more like a £10-15, and goes twice as far as you dilute it down with water.

consider that someone like this:

COMMA SUPER LONGLIFE RED COOLANT READY TO USE 5 L LITRE ANTI FREEZE - SLC5L | eBay

Can sell you it for £15 including posting it to you, you can see that halfords is ripping you off.

 

[Steve_D]

well stil gotta pick up the thermostat from stoke audi, so i'll ask them what their stuff is. other than that, we have a few other motorfactors round here,

Cheers for the help, really appreciate it

 

[griswold]

red coolant from euros £10.79 del or store pick up with code
TRIPLE QX Audi Red Anti Freeze 5Ltr | Euro Car Parts UK’s No.1 Car Parts Retailer

 

[hades-]

when you get the stat from stoke audi ask them for G12

 

[Bradderz_1988]

Isnt it G13 now ????

 

[Steve_D]

Isnt it G13 now ????

Let you know next week when i go down on pay day lol.. unless someone else confirms beforehand

 

[hades-]

no idea i just ask for G12 and get it

 

[aragorn]

yeh its G13 now.

 

[Kingfisher]

If you can, and being really picky, try to use distilled water or at least soft water ( like clean rain water) as it is less inclined to furr up the waterways (think kettle/cental heating pipes etc etc !! )

 

[Steve_D]

If you can, and being really picky, try to use distilled water or at least soft water ( like clean rain water) as it is less inclined to furr up the waterways (think kettle/cental heating pipes etc etc !! )

Typical, i've just sold my marine setup and also the RO-DI Unit, that produces soft, clean 0 PPM water lol

I can see what ur getting at though, maybe it would help in someway

 

[Steve_D]

Well today i FINALLY got round to fitting a new thermostat

Well what a difference that makes. Did all the proper procedures (first time on an audi to fit one) temp rose nice and slow to 90 and sat there... put the heaters on .. still sat at 90 and the heating was much warmer... recently i could hardly feel the heat in the car.

This thing has been running cold for like nearly 4 years now, and all it needed was for this part haha, so after everything was ok and put back went up the m6 for a small drive and it stayed at 90 even with the heating on full blast, not that it stayed high for long i was roasting lol.

What i can see though is that after it was fixed and got upto temp idling there was alot of water? coming from the exhaust! made a small puddle on the floor anyway, levels in the system were not dropping so is this condensation? it was a hell of alot of it! but by the time i came back from the m6 run, totally dry and nothing coming out. The oil temp rose to 90 too another first.

Could that be one of the reasons ive put 3 cats on this thing every MOT haha.. the whole t-stat and cool engine sutuation?

 

[TrisLC]

Did you replace the stat on your drive or did you have access to ramps?

Mine will need doing in the coming months and it would be handy to just do the job at my house.

I recently changed a stat on a MG ZR and it had to be done on the ramps and even that was a PITA lol

 

[aragorn]

Good work. Did a stat on my brothers punto diesel recently with similar improvements. The funny thing was, he'd looked on various Fiat forums and all the mongs on there were saying "these engines just run cold, thats how they are" etc, i said no *** way, it should be getting to temp. After changing it i can see why everyone was avoiding the issue, its a total PIG to change it!

The water out the exhaust is normal, its just condensation due to it being cold out. Once the exhaust has warmed thru from your long drive, it goes away.

And yes, its easy to do the stat on the drive, just jack up the NSF corner.

 

[HibiscusS4]

Stat on a ZR is a horrible job but can be done without ramps, I've done it a few times.

If the engine is running cold it puts more fuel in due to fuel drop out not to make the car run hotter. Engines have to over fuel when cold as the fuel will not all make it to the cylinder in cold air. The problem is when the engine is warm you are then over fueling which can cause bore wash and wear your piston rings, even your crank bearings are at risk as the fuel will get into the oil and thin it out. I would do an oil change on any car that has been overfueling.

And yes this is why you have had to change the cat so often, cats dont like overfueling it melts the internals and fuses them together causing them to become less efficient and sometimes even cause a blockage.

 

[Steve_D]

Did you replace the stat on your drive or did you have access to ramps?

Mine will need doing in the coming months and it would be handy to just do the job at my house.

I recently changed a stat on a MG ZR and it had to be done on the ramps and even that was a PITA lol

I cheated i didnt actualy do it on my drive, mainly as its sloped, i stuck the Offside of the car (wheel width) on the curb jack up the front and put it onto stands (2nd notch curb side 1st notch towards the road) it stays pretty level with ways just not front to back. Plenty of room to get urself and arms underneath, when u put the stat back on, take the housing off the pipe its much easier

I flushed the engine and rad through completely and separately anyway so i didnt have the issue of having trapped old stuff in the engine.

Aragon.. many told me "dont worry at least you will never overheat" but then use more fuel lol. I did my pertol punto when i had it... that was so easy out, in fill.. bleed job done.. this audi was more of a pain good thing on the punto is... their aint much engine so plenty of room haha

 

[Steve_D]

Stat on a ZR is a horrible job but can be done without ramps, I've done it a few times.

If the engine is running cold it puts more fuel in due to fuel drop out not to make the car run hotter. Engines have to over fuel when cold as the fuel will not all make it to the cylinder in cold air. The problem is when the engine is warm you are then over fueling which can cause bore wash and wear your piston rings, even your crank bearings are at risk as the fuel will get into the oil and thin it out. I would do an oil change on any car that has been overfueling.

And yes this is why you have had to change the cat so often, cats dont like overfueling it melts the internals and fuses them together causing them to become less efficient and sometimes even cause a blockage.

Good info matey, well MOT is due this month again so hopefully it might pass, taking a run to blackpool on tuesday so will stick in some redx. Oil change is also due its been 12 months nearly, but i'll let the garage do that before or after the mot... i might if i get the time

 

[Steve_D]

Just did a test on this stat.. it started to open at 58 and took this pic at 65 deg.. root of all my problems finally seen with me own eyes



and one at 100 deg lol...