PlasticMac
Member
Looks correct to me, but @Andrew has one to hand, to confirm it. It's the thermostat itself, and the connector for the heater plug.
Mac.
FSI Owners, Never Ignore An EML.
- Thread starter PlasticMac
- Start date
Mac.
I would say yes. The evidence suggests it is not Mahle replacing the original but Mahle was/is the original at least for a period.
Authentic VW/Audi
If you look carefully at the Mahle picture in your link you can just see the VW/Audi rings and part number have been scratched out.
A better picture, my Mahle thermostat
No problems in 4 years running this MAHLE thermostat, albeit not many miles
Andy
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That is the one I got.
MikeMiles
Member
Very interesting article... I'm a little paranoid about my Fsi and have the coolant temperature as the default display on my colour DIS so am always aware of it - but, after a service and a change to waterless coolant in an effort to reduce overall temps it now commonly runs at 110-112 and frequently hits 114-116 momentarily !!!! This with driving briskly but within speed limits and never pushing the car hard... No warning lights or EML.
Any thoughts what's happening here? Just for longevity I'd like the temperature lower, so all thoughts gratefully received.
Any thoughts what's happening here? Just for longevity I'd like the temperature lower, so all thoughts gratefully received.
PlasticMac
Member
Edit: Scan it first, (ASAP), you may have a failed thermostat heater. The symptoms you describe match an engine, the coolant temperature of which is being controlled by the mechanical element of the thermostat only. Hence you see +110C for a brief time, until the thermostat opens, at 110C, (as it should).
Are you sure your EML is fully functional?
Personally, I'd never put anything, other than a water/G12/13 mix, as the engine was designed for.
The size of the waterways, the thermostat, and, not least, the water pump were not designed for a coolant of a higher viscosity and density.
Flush the waterless stuff out, refill with the correct coolant, then see what temperatures you see, check the functionality of the whole system with VCDS, using the A2OC created FSI lbl file.
Mac.
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Mark Adams
Member
We've noticed that Rover V8 and Micra K11 engines with the waterless coolant tend to run 2-4°C hotter. We use Prestone in everything now, and have done for years.
PlasticMac
Member
The engine/coolant temperature is controlled by the ECU and, thermostat. Nothing, (other than a fault), will change that.
Around town, (low engine load), the engine, (well mine anyway), will run at 90 -100C, and the 110C thermostat will rarely open.
When driving briskly, (higher engine load), the ECU will activate the dual temperature thermostat, dropping the temperature at which the thermostat opens to 85C.
My guess is that a failed thermostat heater, and failure to act on the EML that results, has killed more FSIs than any inlet flap related failures.
Mac
PlasticMac
Member
The Evans ( waterless coolant manufacturer), website says:
"Water has superior heat transfer capabilities but water’s low boiling point is close to the operating temperature of an engine, and water can cause corrosion"
What they don't say, is that adding the correct coolant, at the recommended ratio, raises the boiling point of the mix, (as well as inhibiting corrosion), and because the coolant system runs at above atmospheric pressure, the boiling point is further raised.
The inferior heat transfer capabilities of waterless coolant probably explains the higher engine temperatures.
Mac.
MikeMiles
Member
Not that I notice - it starts and runs quite normally...
PlasticMac
Member
That's probably why you haven't got an EML telling you that you have a problem. Someone has, (probably), disabled the EML.
As I've suggested, get it scanned, and don't drive briskly until you have.
Mac.
Good Evening Mike,
The EML should light up briefly with others at start up, suggest you watch carefully.
Exactly what you should see is detailed here
New A2 owner few questions
Bought the little A2 about a week ago now it’s a 2003 1.6fsi with the sky roof not sure what colour it’s just looks like a light metallic green. The car has done 90,000 miles, I’m not sure how many miles people usually get out of a 1.6 as I’ve always had diesel cars so if anyone can shed light...
www.a2oc.net
Andy
MikeMiles
Member
Hi Andrew and Mac, yes the dash lights up correctly in the test phase and then extinguishes correctly when the engine fires - no lights on briefly otherwise, and then drives fine other than the high temperatures. I can scan it tomorrow and check for codes... Reading these replies, my suspicions go towards the thermostat heater element... Thankyou Gents 
Good. If the thermostat heating element is faulty it would be picked up by the ECU and the EML illuminated, no EML implies thermostat healthy and coolant temperature is normal, scan it anyway.Hi Andrew and Mac, yes the dash lights up correctly in the test phase and then extinguishes correctly when the engine fires - no lights on briefly otherwise, and then drives fine other than the high temperatures. I can scan it tomorrow and check for codes... Reading these replies, my suspicions go towards the thermostat heater element... Thankyou Gents
I am beginning to think you are over concerned about the coolant at 110℃, it is normal. Maybe for reassurance read the first two posts in my little thread, but it does take some scrutiny.
A Slightly Geekish Look At FSI Coolant Warm-up
Only read if interested! Currently I am involved in constructing a label file for the FSI ECU, a small portion of which is the coolant groups 130-137 and along with my contributions to Evros's current coolant thread I have have become intrigued with FSI coolant warm-up, how it behaves and what...
www.a2oc.net
If your ambition is run at a lower coolant temperature then I see two ways this can be achieved.
1. Remap the ECU, either use ProBoost or engage an expert to remap using 100℃ (or whatever you choose) for the coolant setpoint instead of 110℃ and bearing in mind other considerations.
2. Use a thermostat with a lower opening temperature somehow. Interestingly such a thermostat does exist by FAE on AutoDoc
but appears completely out of stock everywhere. Possibly a DIY wax change if such a change is viable but would need expertise and skill, but intent was shown by one member.
Andy
PlasticMac
Member
I have no knowledge of the CDIS, but if you are looking at the actual engine temperature, at the engine outflow, then @Andrew is right, monitoring it will only keep you awake at night, and around110C is perfectly normal for an FSI, unless the engine is under significant and continuous load.
The way to check if all is well, is to log engine temperature, coolant temperature, and engine load, over a varied drive.
As long as the drive includes a cruise at 70 ish, to check if the lower engine temperature is activated, as it should.
Tinkering with the engine temperatures is not a good idea, (imo). At best mpg will decrease, (if the engine doesn't reach expected temperature, the mixture will be kept rich).
If you really want to run the engine at a lower temperature, then go with ProBoost.
The FSI was designed to run at a higher temperature, for good reason, and yours, Andrew's and mine, have been doing so quite happily for nearly 20 years.
Mac.
The way to check if all is well, is to log engine temperature, coolant temperature, and engine load, over a varied drive.
As long as the drive includes a cruise at 70 ish, to check if the lower engine temperature is activated, as it should.
Tinkering with the engine temperatures is not a good idea, (imo). At best mpg will decrease, (if the engine doesn't reach expected temperature, the mixture will be kept rich).
If you really want to run the engine at a lower temperature, then go with ProBoost.
The FSI was designed to run at a higher temperature, for good reason, and yours, Andrew's and mine, have been doing so quite happily for nearly 20 years.
Mac.
Clackers
Member
it may or may not be of use to you, but I am currently breaking an fsi so any pipes etc that yo need I can remove. Be very careful around the thermostat housing, there is a pipe that comes off the housing pointing straight up that often shears off, thus meaning you will need a new housing.I have a couple on the shelf should this happen. It happened on my last fsi, and then the top rad pipe decided to shear by the rad...purely because all the plastics are getting old and brittle, thankfully my stash of fsi spares came to my rescue.
Phil_B
Member
I have ordered This from Ebay. Now to get it fitted, and bled....
Since @PlasticMac comment about spirited driving i have made sure I don't go above 4k RPM on a steady drive, and don't accelerate hard either.
Ideally I'd like to get my Coupe on the road before I do this, and fit a new OSF Wishbone as the ball joint is clonking now!!!
Clutch for the 800 Coupe is somewhere between my friends house in Kansas and my house in Surrey at present.
Since @PlasticMac comment about spirited driving i have made sure I don't go above 4k RPM on a steady drive, and don't accelerate hard either.
Ideally I'd like to get my Coupe on the road before I do this, and fit a new OSF Wishbone as the ball joint is clonking now!!!
Clutch for the 800 Coupe is somewhere between my friends house in Kansas and my house in Surrey at present.