Is my MAF on it's way out? (S3 8P 265)

Daveyonthemove

Daveyonthemove

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Recently I've been logging the MAF (using Torque and OBD Doctor) on my car as I've had a few things done to it and wanted to see if there was any change registered.
The car has been logged as it was the day I collected it and then after a fuel filter change, after a Carbon Clean on the engine, after new coil packs and spark plugs, and after a remap.
The maximum figure I have seen is 183 g/s. The lowest is 178.4 g/s (before all the work mentioned above).

After each item was replaced or the remap installed there has been a noticeable improvement, certainly with the remap, but the MAF readings don't indicate much of a change (if anything they are low even for a standard car).

The car is performing well, so I'm not sure why the readings are so far out. Anybody able to shed some light for me?
 
A few wise words if its not broken no need to fix
 
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Advice I have always believed in. But i'm trying to diagnose if it is broken. Then I can leave it or fix it accordingly ;)
 
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audi upgrades
If you are going to do it with IPA definitely worth using the spray one much easier.
Used spray IPA to clean my MAF. Just make sure its totally dry before putting it back on, mine wasn't particularly dirty when I laste cleaned it anyway. The throttle body on the other hand....
 
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I removed it today and gave it a clean. It had a layer of grime on it, but nothing too serious. I've cleaned it up now and the car starts and revs fine (it did anyway) so I will take it for a drive later and check all is well.
Thanks for the advice above, very much appreciated.
 
Daveyonthemove said:
I removed it today and gave it a clean. It had a layer of grime on it, but nothing too serious. I've cleaned it up now and the car starts and revs fine (it did anyway) so I will take it for a drive later and check all is well.
Thanks for the advice above, very much appreciated.
Click to expand...
Lets hope thats it all fixed and you dont find anymore probs cause we only do soloutions .:thumbs up::thumbs up::thumbs up:
 
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I haven't done a max MAF run yet as i've washed the car and it's been raining most of the afternoon.
I'll probably do one tomorrow morning and see if there is an improvement.
 
MAF Max run this morning, 186.2 g/s max reading.
Car seems to be driving perfectly fine, power doesn't feel lacking. Boost peaks at 13psi (with Bluefin stage 1).

Any thoughts?
 
Maybe you frightened it enough with doing all those tests that its gave up the Ghost , best mot to try and explain the unexplained .:thumbs up:
 
186 g/s on an S3 is way too low - that equates to 230 ish bhp. You should be reading around 250 g/s.

You have an issue - did you check your DV? Log block 115 (boost) and see if your actual matches your requested. Look for a big boost spike when the power comes in. If you see that, then you have a leak.
 
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I've tried a few times to log things with the OBD reader (Torque) but for some reason my bluetooth dongle refused to connect.
So I decided to spend 10 mins removing the DV and checking it, and discovered that it has split.




I've already ordered a replacement so that will be fitted as soon as it arrives. I'm actually quite glad it's the DV because it's cheap and easy to replace, and also means I will get more performance from an already quick car.
Good result.
 
Please no more Photobucket! Just upload the pics if possible.
 
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Daveyonthemove said:
I didn't expect PB to do that, sorry!
I'll try and attach them now.
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No worries. Unfortunately Photobucket turned to a member only paid model last year, causing millions of blogs, forums and other 3rd party sites to lose their image access over night.
 
Bit of a result there Davey, I think that might transform the car because when i fitted my DV+ it transformed mine which had the later version without the diaphragm and had been getting worse over a period of time.
 
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paddy said:
Bit of a result there Davey, I think that might transform the car because when i fitted my DV+ it transformed mine which had the later version without the diaphragm and had been getting worse over a period of time.
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Yeah, oddly I'm quite happy about it.
The MAF readings suggest a missing 60-70bhp (assuming it makes 300bhp on stage one) and I already thought this car was running well and assumed false readings.
It looks like readings are true (to a degree) meaning there is more power to be had for a meagre £30! for the sake of a small outlay and 10 mins of spannering, this is great news.
 
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A simple yet fairly accurate method of calculating hp from g/s is to divide the figure by 0.8.
183g/s equates to 229bhp which is way too low.
If running an aftermarket intake then that equation really depends on how accurate the maf scaling is. This can be checked by looking at the ltft or long term fuel trims with vcds as that shows how much the ecu is having to compensate the mixture using data from the lambda sensor.
If it's around 5 then it's close to oem and will be fairly accurate, but most intakes read over that and some are nearer 15. That means there is more air in the system than is being calculated by the maf and the ecu adds more fuel to the mixture. In this scenario the actual airflow is higher than what is being recorded by the maf.
When I had my APR'd 2+ S3 the ltft was around 2 and I regularly saw over 300g/s

God I miss that car!
 
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You can also run the car with the maf unplugged, if it runs better that's a good indication of a dodgy maf!
 
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"God I miss that car!"

Lucky for the rest of us you are still looking in on the 8P threads :)

Believe it of not i still miss my 3.2 but then they say your first love is the best ....
 
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paddy said:
"God I miss that car!"

Lucky for the rest of us you are still looking in on the 8P threads :)

Believe it of not i still miss my 3.2 but then they say your first love is the best ....
Click to expand...

I think I am on a slippery slope with mine, hope to get a few more good years out of her. Lots of fun to drive windows down listening to the roar but bark is worse than it bite with this one.
 
Tonight I replaced the DV while my GF's son replaced front disks and pads.
Obviously I'm taking my time in the car until the brakes bed in properly, but the difference is immediately apparent.
Much better throttle response, 6th gear now pulls like 4th gear and what I thought was a bit of turbo lag is obviously a result of the boost leak.
Gave it a little burst in 6th on a dual carriageway on the way home and noticed that clutch now slips!

So if anyone can recommend a decent clutch at a decent price, it would be appreciated. I'll remove the Bluefin for now to prolong it's life while I save up the money.
I've got to be due some good luck soon...
 
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Daveyonthemove said:
Tonight I replaced the DV while my GF's son replaced front disks and pads.
Obviously I'm taking my time in the car until the brakes bed in properly, but the difference is immediately apparent.
Much better throttle response, 6th gear now pulls like 4th gear and what I thought was a bit of turbo lag is obviously a result of the boost leak.
Gave it a little burst in 6th on a dual carriageway on the way home and noticed that clutch now slips!

So if anyone can recommend a decent clutch at a decent price, it would be appreciated. I'll remove the Bluefin for now to prolong it's life while I save up the money.
I've got to be due some good luck soon...
Click to expand...
Davey, what do you mean remove bluefin to prolong its life?
 
audis3UK said:
Davey, what do you mean remove bluefin to prolong its life?
Click to expand...
The Bluefin raised the BHP and Torque levels, so driving it around with more torque was adding more stress to a worn clutch.
Removing the Bluefin put the torque figure back to factory, and caused less stress on the clutch so I could still use it and find the time to get a clutch and fit it.

I did find one pretty quickly and fitted an uprated clutch and DMF so I could push for stage 2 at a later date.
 
How is you car doing on the stage 2 bluefin now? What bhp reading did you get? Have you ever got the bhp reading from an obd2 device?
 
audis3UK said:
How is you car doing on the stage 2 bluefin now? What bhp reading did you get? Have you ever got the bhp reading from an obd2 device?
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I had stage 2 for a while, but noticed more oil consumption so I reverted back to stage 1.
However, since reverting back I have found and replaced split PCV hoses and the consumption is less, but there difference between the two wasn't really worth going back to.

Using the MAF to get a base reading, BHP on stock map was 268bhp (from memory) so roughly where I would expect it to be.
Using the same method on stage 1 I am getting 300bhp.
Stage 2 saw 305bhp, but it did accelerate harder lower down but seemed to run out of power faster higher up the rev range.

This weekend I am planning to do a full service of all filters, plugs and oil plus haldex. It's not really needed, but I want to try a thicker oil and may put stage 2 back on for a short while, but my plans are to visit R-tech in the next month or two and get a custom map put on the car.
 
Daveyonthemove said:
I had stage 2 for a while, but noticed more oil consumption so I reverted back to stage 1.
However, since reverting back I have found and replaced split PCV hoses and the consumption is less, but there difference between the two wasn't really worth going back to.

Using the MAF to get a base reading, BHP on stock map was 268bhp (from memory) so roughly where I would expect it to be.
Using the same method on stage 1 I am getting 300bhp.
Stage 2 saw 305bhp, but it did accelerate harder lower down but seemed to run out of power faster higher up the rev range.

This weekend I am planning to do a full service of all filters, plugs and oil plus haldex. It's not really needed, but I want to try a thicker oil and may put stage 2 back on for a short while, but my plans are to visit R-tech in the next month or two and get a custom map put on the car.
Click to expand...

The Millers Nanodrive oil is highly recommended at 5W - 40 viscosity. In addition to using it in my S3 at stage 2+, I use it in my Mk 4 GTi 1.8T. This car has done 131,000 miles and the engine is super smooth and importantly, burns no oil.
If you can stretch to uprated fuel pump internals, the difference after an RTech remap will blow you away compared to Superchips
 
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I am currently using that oil and have topped up a litre over the last 10k or so.
I'm going slightly thicker this time. If it still consumes oil then I will start looking at removing the head and inspecting things. obviously it's cheaper to top up oil or try some different grades for now, so that is the short term plan.
If things don't improve then I won't be visiting R-tech until it's sorted.
 
I’m using 5w 40 from Penrite and it does seem to be burning oil quite a bit less than Castrol edge 5w30. I’ll try and do some bhp read outs from my obd this weekend
 
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Here is my readout seem I only have 244 hp with stage 2 bluefin
 

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audis3UK said:
Here is my readout seem I only have 244 hp with stage 2 bluefin
Click to expand...
Don't use the HP function on Torque, it's not accurate.
You need to take the Max MAF reading on a 3rd gear run up to the redline.
Then divide that figure by 0.80 and that will give you a BHP number.

Do it on stock map too as it will give you an idea of accuracy.
 
I’ll go back to stage 1 but I think that will throw a cel as I have decat and no cat fooler.

Thanks for the bhp calculation advice
 
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audis3UK said:
I’ll go back to stage 1 but I think that will throw a cel as I have decat and no cat fooler.

Thanks for the bhp calculation advice
Click to expand...

It will only be for one run so it should drive ok even with a CEL lit up.
Get a good base figure and then you can test the stage 2 and see if there is an improvement and it will probably feel a bit sharper as they tend to after being installed.

I'm reverting mine to stock map today, the Stage 2 on mine feels like it spikes boost too much and runs out of steam to early.
I've emailed SC and asked for my stage 1 file again, and will leave that on until I get to R-tech at some point this month.
 
Great ordered one of these so hopefully can go back to stock or stage one more easily. Found one on eBay for under £3

M18x1.5 Lambda Oxygen Sensor Bung
 
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