Hi guys, last w/e I went from Salisbury to Oxford and used half a tank and would normally use quarter, I was doing a steady 70mph and the trip computer was showing a poor 29-31 mpg. Someone has said to me it could the MAF sensor but it idel's fine and no starting problems is there anything else which could course my MPG to drop like it has?

Cheer's

Baz

You need to get a diagnostic done with VCDS. Could many things including the MAF.

MAF, Coolant temp sensor, Lambda to name but a few..!

Needs VCDS to be sure.

Thanks guy's, would the VCDS still flag something up even though it's not displaying any faults on the dash?

Binding rear calipers? I had an issue with my handbrake not releasing properly. If you can try and go for a slow drive somewhere and see if you slow down faster than you would expect. Or try going for a drive and not using the brakes. Pull over somewhere after 5 mins or so and carefully stick a finger on each disc and see if they're hot.

Cheer's Schern, i will give it go coz i have noticed a squeak coming from the rear brakes when slowing down.

I have a similar problem, if I drive slow around town I can get roughly 32 MPG, but on longer journeys its more like 29 MPG, which in itself is weird as surely it should be the other way around

Do I need a specialist to do the VCDS and if so can anyone recommend anywhere in the north-east

Check to see whether you have the old black coolant temp sensor fitted. It's located at the engine end of the top rad hose. It's one of the most common failures on VAG cars causing either the temp gauge to read wrongly or the ECU to fuel incorrectly. Replace with a genuine VAG CTS, & not cheap aftermaket version from ebay or motor factors.

sorry im not up to speed with this engine yet, am I in the right area

if so could you recommend somewhere I could pick up the correct CTS (or would it be direct from VAG ?

Is there a plug connected to the green sensor? Hard to tell.

yep that's the one. i replaced it early in the year as it stopped working.

sorry im not up to speed with this engine yet, am I in the right area

if so could you recommend somewhere I could pick up the correct CTS (or would it be direct from VAG ?

Yes that's it. You do in fact have a green CTS, but is it genuine VAG?

You also seem to have a lot of oil splatter around that area which may be down to a split vacuum or boost pipe. Or is it leaking coolant from a cracked CTS housing?

I do hope you haven't got a cone air filter on the end of that large silicone pipe connected to the MAF. If you do & it's in the engine bay that will be losing you 5/10 bhp due to heat soak.

Edited 22 October, 201213 yr by pauldazzle

thx, not sure if its genuine or not, is there anyway of telling, have only had the car a few months and there is no paper work about the CTS... the splatter did worry me aswell, coolant levels havent dropped but oil levels are a little less than when I 1st got the car,,

would i need to take it to a garage for them to check the vacuum and boost pipes ?

and yes I do have a HKS mushroom filter on the end of the silicone pipe, but its right up against the cold air feed, and I havent noticed any difference in power since fitting it, but I will be putting the original airbox back on, albeit modified so it blocks out most the heat..

The only way to tell if it's a genuine CTS is to remove it & look for a VAG emblem. If you know anyone with VCDS the CTS can be monitored which would show any discrepency.

You would really need to get a smoke test done to if you have a split in any of the vacuum & boost pipework.

CAI's work well, but personally I have stuck with the standard airbox with a decent panel filter, K&N Green Cotton etc. The first 1.8T VAG car I owned was fitted with a K&N cone down where the OEM box would be, & when I had it Revo'd on a Rolling Road it produced 8bhp less than running with the standard airbox with a new standard filter in!

Thx, I will bare it in mind, but car is plenty powerful enough for me,

I have some engine degreaser so I will clean it up as much as I can and keep an eye on it,

hopefully get it in a garage next month if the oil comes back