TDI poor MPG after cleaning TB!

Westy

Westy

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Anyone got any suggestion as to why I woul get poor mpg after cleaning the TB? I've just done 65 miles, changing gear at 2k revs and struggled to get 42mpg when I've been getting 50mpg with a fair few blasts!

I removed the TB and EGR delete section on Saturday for a clean. As you can see, it wasn't even that bad!

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I've checked all the bolts are tight and so is the inlet boost hose (after it blew off this morning!) and I've checked all electrical plugs were reconnected.

Any suggestions?
 
I'd hazard a guess at it being an air leak of some sort. Did you use new o rings? Mine were useless when I took mine off, flat and didn't create a decent seal on refitting so had to get new ones.

The anti shudder valve is always open when the engine is running, so it shouldn't be anything to do with the mechanical side of it, unless for some reason it now cannot open fully? It only closes when you kill the ignition, to aid stopping the engine.
 
Thanks smithy this was my guess too. I spoke to Audi yesterday and they said there should be a paper gasket as well as two o rings but I don't have the gasket on mine. I've ordered all 3 parts but they won't be in till Wednesday and I've got a good 160 miles to cover in that time!
 
A little better this morning. Just drive 50 miles like an old woman as economically as possible and managed 46.5mpg. Good but not normal. Only difference between this mornings drive and last nights was that this morning was mainly a-roads 40-60mph and last night was all 70ish on a dual carriageway. So maybe the air leak is more prominent the higher the revs. Hopefully these new seals will do the trick.

Can anyone tell me if there's meant to be a seal on the inlet hose or does the metal collar just slide into the EGR and lock in with the circlip?!
 
Just called Audi back to order the seal for the hose and the fella seems to think its a paper gasket! Doesn't sound right to me but I can't check ETKA till I get home.

I've ordered the following:

O-ring £5.30
O-ring £3.94
Gasket £3.26

I've no idea which o-ring is which as there's one that goes between TB and inlet mani and one between TB and EGR.
 
The paper gasket goes on the end of the EGR pipe that you no longer have as you have the delete pipe, so you won't need it.

There are 2 o rings like you said, and a rubber seal on the end of the inlet boost hose which id replace. Hope this helps!
 
SmithyAG said:
The paper gasket goes on the end of the EGR pipe that you no longer have as you have the delete pipe, so you won't need it.

There are 2 o rings like you said, and a rubber seal on the end of the inlet boost hose which id replace. Hope this helps!
Click to expand...

Cheers. Stupid tit at Audi can't find anything on his system. I'll get on ETKA when I get home and find the part number.
 
No worries mate. If I remember correctly they are on different diagrams on etka, the o rings are on the EGR diagram and the seal on the 'charge cooler' diagram.
 
SmithyAG said:
No worries mate. If I remember correctly they are on different diagrams on etka, the o rings are on the EGR diagram and the seal on the 'charge cooler' diagram.
Click to expand...

I've been looking on vagcat but can't find the seal on the charge cooler diagram. It does list all te other seals but they are all different sizes. I cans find an EGR diagram at all on vagcat.
 
I'd look it up for you but I'm in scotland with just my phone until Saturday! Sorry pal!
 
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I've been looking at those two diagrams on VAGCAT but it's still not particularly clear as the inlet hose doesn't look the same as the real thing. Just need to work out which end of the system is coming from the turbo and which end is going into the EGR valve. :think:
 
After closer inspection I do have a seal on the inlet hose.

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Is it possible to not seat the hose properly so it could leak?!

I'm getting my exhaust looked at on Friday as its getting quite noisey. I know an exhaust leak can effect MPG.
 
The inlet hose is a poor fit at the best of times, I think the lugs on mine are past it as it doesn't matter what I do it always sits about 2-3mm out.
 
New seals on:

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Fingers crossed it'll help. I now see why everyone moans about these seals and the boost hose clip connections! I could see the bottom of the inlet hose where it connects to the next hose and there is oil all round it where its obviously been blowing. Might have to go back to Audi for some more seals! Maybe a Easter weekend job. At £6.12 a seal it could work out quite expensive to do the whole lot :faint:
 
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