New Member FSI colour Storm

[PlasticMac]

Keen to see if it would make any difference I got a new G83 sensor and fitted it. After a shortish drive the temp soared over 90 and the fan didn't seem to kick in.. bit frustrating. Taken a step back. It was at least usable before. If I unplug the replacement sensor would it in theory just put the fan on all the time?

Not sure what's going on. Failed G83 shouldn't cause the engine to overheat. A failed G83 should trigger the fan to run at low speed. If that doesn't get the engine temperature under control, the fan will runs at high speed.
But, (important But), this will only happen if the thermostat is opening, otherwise there is no flow through the radiator. Under light to medium load, the engine will run at around 110C, and the mechanical element of the thermostat will be in control of temperature.
We're guessing, which doesn't work. We don't even know if the engine is actually overheating.
The only accurate measure of engine temperature is via the OBD port. The engine temperature sensor is actually two sensor in one moulding. One sensor feeds the ECU, (and is in control), the other only feeds the dash cluster, which, in turn, drives the gauge.
You need a registered copy of VCDS Lite, and log some temperature data measuring blocks, to see what is really going on. Before, (engine outlet), and after, (radiator outlet), the radiator. Plus engine speed and load.
Are you fitting genuine VAG sensors? Aftermarket sensors can be less than perfect.
Even an engine scan with the free VCDS Lite would help. It will tell you if the G62 or G83 are dodgy
Mac.
Edit: A scan will flag a failed sensor, but not one that's inaccurate.
Mac.

 

[Andrew]

Keen to see if it would make any difference I got a new G83 sensor and fitted it. After a shortish drive the temp soared over 90 and the fan didn't seem to kick in.. bit frustrating. Taken a step back. It was at least usable before. If I unplug the replacement sensor would it in theory just put the fan on all the time?

Good Afternoon Richie,

Oh dear, there was me thinking a new G83 would tick that one off the list instead it has created a new problem.

I am surprised it exceeded 90℃ so quickly, (I assume this figure is from manual observation of the cluster gauge). It takes serious coolant overheating to push the gauge reading over 90℃, likely in excess of 115℃. By contrast today I would expect my FSI would struggle from cold to make FSI temperatures after 15 minutes of normal free running. (For anybody reading in the future the ambient temperature is barely reaching a daytime peak of 5℃ today).

Head problems spring naturally to mind but nothing has been posted about frequent coolant top ups or coolant being forced out of the coolant tank? Probably a sniff test is worth doing to rule it out (or in).

As Mac has said VCDS Lite is the way to go, even with the free unregistered Lite coolant temperature will be available. However the registered Lite (or full VCDS) will be needed to look at the coolant Groups that matter, namely 130,131 &132.

You are not that far away and if you can make across to me at least we can look and post these blocks and maybe a short drive to log coolant behaviour if temperatures not too high.

Andy

 

[Andrew]

Hi Andy,

Yes, replacing the inlet manifold made no difference. I did pin the arm whilst installing as I did some research before undertaking the work.
I wasn't aware of the flap adaptation. Is this something only a specialist will be able to do?
.......

Good Evening Richie,

Apologies for the indecent time it has taken to reply to your question but I am so busy at the moment.

Specialist not really needed just someone who has the software capable of of performing the flap adaptation such has VCDS (or similar). I understand flap adaptation is a calibration process of the flap potentiometer so the ECU knows what are the 'new' positions of flaps fully open and closed, which I assume it must do by opening and closing the flaps at least once during adaptation.

All I know, I am not an expert, is the Workshop Manual cites flap adaptation is required after manifold replacement. Now becomes unclear, Ross-Tech (the authors of VCDS) document the required procedure but members report it simply does not work. However there are reports that running Basic Settings works, thought I would investigate.

The relevant Measuring Block Group for manifold flaps is 142 as seen here, (ignition is on with engine off). My flaps are healthy, note the 'ADP. O.K.' In Block 4, yours may well say ERROR.

Information for the flap adaptation are listed in the .lbl file, basically need the engine running to ensure a vacuum to drive the flap vacuum actuator.

; Ignition ON,Engine ON (Idle)
; Activate Basic Setting
; Engine Idling > Field 4 = "Test ON"
; Wait Until Field 4 Displays "ADP ok"

I never saw a 'Test ON' but possibly of such short duration I missed it.

I found two ways of performing the adaptation that really amount to the same.

In the first way, when at the above Measuring Block screen click 'Switch To Basic Settings' at the bottom left to enter Basic Settings. It does not hang around, you do nothing, it immediately starts the adaptation, note the Block 4 now displays 'ADP. Run'

At this point like an idiot I remembered I need the engine on idle! I fired her up and within about 3 seconds the 'ADP. Run' changed to 'ADP. O.K.', checked back in Measuring Blocks and all had ended well.

The second way I found is more direct., click 'Basic Settings - 04' in the 'Open Controller' screen.

On entering the Basic Settings screen, same as above but the Group and Blocks are blank, a choice either enter 142, in the Group box and click 'GO' or select the input manifold line in the drop down menu 'Documented basic settings groups can be selected here' ( scroll down). As before the adaptation starts immediately with 'Adp. Run' and followed hopefully by 'Adp. O.K.'

If not done previously clear any fault codes and with luck the EML illumination will have not come back.

Andy

 

[PlasticMac]

Each time you switch the ignition on, and before the engine starts, the vacuum to the flap actuator is vented, to ensure the flap are in the down, (inlet fully open), position. As soon as the engine starts, vacuum is applied to the actuator, and the flaps rise, to the stratified position.
There is a potentiometer on the flap spindle, which tells the ECU the position of the flap spindle, and flaps.
Each time this happens, the ECU expects the voltage from the potentiometer to be the same as it was the last time Adaptation was run.
If the two do not match, a fault code will be stored,and the EML will illuminate. It takes three, (I think), consecutive errors, on one driving session, to trigger the EML. The error count is reset if the ignition is turned off.
If you don't get an error, then, in theory, you don't need to run the adaptation.
But, if the manifold has been worked on, it is very unlikely that when refitted, it is in exactly the same position as before. There is a small tolerance on the potentiometer voltage, so a small difference will not trigger an error immediately, but the tolerance may well be exhausted.
So it would be a very good idea to run it, to avoid errors in the near future. Prevention better than cure.
If you go for VCDS Lite, then you'll need the new label file.
If you send me a PM, Subject BADLite, I'll send you the file un reply.
Mac.

 

[Richie Mc]

So, left it alone for a bit while I was busy at work. But the car was struggling to start even from cold. Had similar symptoms on cars before and a fuel pump has been the culprit on several occasions. So fitted a new lift pump as they are relatively inexpensive and an easy job. Pretty quickly found a huge fuel leak..
Can we assume one of the injectors didn't seal properly?

 

[PlasticMac]

So, left it alone for a bit while I was busy at work. But the car was struggling to start even from cold. Had similar symptoms on cars before and a fuel pump has been the culprit on several occasions. So fitted a new lift pump as they are relatively inexpensive and an easy job. Pretty quickly found a huge fuel leak..
Can we assume one of the injectors didn't seal properly?

The lift pump is in the tank, where is the leak?
Was there no obvious leak before you fitted the new pump?
Are you thinking you've fixed the fuel pressure, and now it leaks, because you have decent fuel pressure?
Mac