Running Temperatuire -- what's the verdict?

[alg]

Changed my thermostat at the garage meet with the following results.

Before: approx 65º (3.75 notches below 90º) at speed - 90º in town
After: approx 78º (1.75 notches below 90º) at speed - 90º in town

Temperatures based on 6 notches between 50º and 90º @ 6.66º per notch.

So an improvement.

Thats what I am seeing Angus with the new thermostat

[Ross]

What were Audi thinking when they scaled the guage?! Good to hear you had an improvement Angus - when I get brave enough I'm going to give this one a try. I'm still 2 notches above 50 (63.2deg ) at motorway speeds, and I' rather see temps a bit higher (would probably make the heater more effective too, it's rather dire when coolant temps are that low!)

[HPmuirt]

Thats what I am seeing Angus with the new thermostat

I hhave a new water pump and a new thermostat and still reads 70 at speed and 90 in traffic

Cheers n

Si

[Jamo]

Mine goes up to about 88 average then up to 90-92 then the fan kicks in.

Even on motorway runs it's in the high 80's.

I replaced the thermostat when i replaced the Rad last year (and i put a new short stat hose on).

[BRY]

I hhave a new water pump and a new thermostat and still read 70 in traffic and 90 in traffic

Cheers n

Si

So what does it read in traffic then?

[AAH!]

I was wondering if the slight variation in coolant hoses on the RS2 along with the faster pumping water pump was to help with maintaining constant temperatures. Maybe these where small modifications to help cooling on one of the final variations of the IL 5?

Also IIRC it was mentioned that if the expansion tank filler cap doesn't rattle it suggests that the pressure relief valve isn't working and therefore it should be replaced. Maybe this is another factor to include in the equation of the lack of a constant temperature .

Was there a reason for the 4 pins MFTS to be superceeded by the 3 pin the MFTS? I think I read somewhere that the later 3 pin MFTS give a tad cooler readings on the gauge. I Also seem to remember that a faulty MFTS can give high readings and can put you into limp home mode.

I suppose at the end of the day and what this is really all about is that I want to ensure is that the coolant is get up to a higher enough temperature for the temperature sensor (G62) to tell the ecu that the engine is warm enough to stop enriching the fuel mixture. At what temperature does this happen?

enough of the waffle ... Angus

[alg]

I was wondering if the slight variation in coolant hoses on the RS2 along with the faster pumping water pump was to help with maintaining constant temperatures. Maybe these where small modifications to help cooling on one of the final variations of the IL 5?

Also IIRC it was mentioned that if the expansion tank filler cap doesn't rattle it suggests that the pressure relief valve isn't working and therefore it should be replaced. Maybe this is another factor to include in the equation of the lack of a constant temperature .

Was there a reason for the 4 pins MFTS to be superceeded by the 3 pin the MFTS? I think I read somewhere that the later 3 pin MFTS give a tad cooler readings on the gauge. I Also seem to remember that a faulty MFTS can give high readings and can put you into limp home mode.

I suppose at the end of the day and what this is really all about is that I want to ensure is that the coolant is get up to a higher enough temperature for the temperature sensor (G62) to tell the ecu that the engine is warm enough to stop enriching the fuel mixture. At what temperature does this happen?

enough of the waffle ... Angus

Quality waffle Angus Do not think much difference between RS2 and S2 as temperature readings similar in 8 years of driving one then the other.
Might try a new MFTS when I can raise the effort.
Sorry to have missed the meet and your B&Q

[AAH!]

Quality waffle

Thank you, i do try and do my best.

I could have just asked:

"at what temp does the temperature sensor (G62) tell the ecu that the engine is warm enough to stop enriching the fuel mixture"

but it just not the same.

Still interested in the answer though.

[Sweeper]

Well i'm probably change my 80C VW VR6 thermostat to the original one , but first can anybody tell me :

1) How the original S2 thermostat works in hot weather enviroment , like 30C all day long with high town traffic ?

2) On track days , drag races and s.o ? As with 5XX HP engine is kind of important to not get hot =]

[maRS2]

would not be better to check the reading of the G62 (with vag com or aircon code) instead of looking to the reading of one sensore who as nothing to do with the ecu management exept for safe mode?

I mean even if the MFTS read 50° water doesn't mean you have 50° water and the only one who tell the ECU when to get reacher mixture is G62 so why not try to see what G62 is seeing

[Quattro_Vaassen]

Changed my thermostat at the garage meet with the following results.

Before: approx 65º (3.75 notches below 90º) at speed - 90º in town
After: approx 78º (1.75 notches below 90º) at speed - 90º in town

Temperatures based on 6 notches between 50º and 90º @ 6.66º per notch.

So an improvement.

hi,

got the same results when changing the thermostat.

i spoke to the previous owner of my S2 and he told me that the problem could also be in our dashboards......there should be a sort of voltage regulator, and if that one isn`t working correctly than we could just READ a wrong temperature!!!!! don`t ask me where it`s mounted, but it`s there....
he told me that one of a VW Golf (mark III) would be the same.

i saw above that i can read the coolant temp. by using the display of the aircon???
can anyone tell me how?

greetz Erik

[maRS2]

you can check it on chanel 51 on your aircon

Here is how to do it: http://www.audiworld.com/tech/int6.shtml

[maRS2]

I just made some test to see difference reading between dashboard and AC chanel 51

dash board ________ AC chanel 51
50 65
1 notche 71
2 notche 77
3 notche 85
4 notche 87
5 notche 89
90 90

Fan kick's in at 92° C on Chanel 51

It seams that the temperature difference in between notche's is not a constante value 6,66° but more decreasing value
like 6° on the lower and only 2 or 1° close to 90°

I will do some highway monitoring tonight

My car have new Thermostat and new water bottle and cap and no bleed in the water hose. This point is importante because old cap or water bleed will decrease pressure in pipes and theire for increase water temp.

[AAH!]

I've just looked through the workshop manual and confirmed that the normal operating temperature is between 85ºc and 105ºc. I also found out that the MFTS (F76) puts the car into low boost mode when the engine temperature reaches approximately 118ºc and puts in back into normal boost mode once the temperature drops to approximatley 113ºc.

This got me thinking about the 3 little dots on the water temperature gauge just below the notches (see photo below). The first dot after the 50ºc mark could represent 85ºc (i.e. bottom end of normal running temp) with each notch thereafter representing a 1ºc increment up to 90ºc. After the 90ºc mark each notch could represent 3.75ºc which would take you to the 120ºc mark. Using this scaling theory the second dot could represent 105ºc (i.e. top end of normal running temp) and the third dot 113ºc could indicate where the MFTS does its boost controlling thing.

If this is correct it is a very bizarre and un-german way of marking up a gauge.

Based on this theory, my new 87ºc thermostat sits at just over 88ºc at speed which sounds about right and hopefully it means that many cars are not running quite as low temps as originally thought.

Incidentally, I also found a comment in the RS2 workshop manual stating the reason for the modified coolant hoses that fixes to the thermostat in the in the RS2 was to provide an "additional outlet for coolant expansion"

Angus

Also: Manual confirms that expansion tank filler cap must have a functioning pressure relief valve that releases between 1.2-1.5bar.

[jubjub]

Quality waffle Angus

[QUOTE ahh]
Thank you, i do try and do my best.
I could have just asked:...........
[QUOTE]



Quality