MPG has just fallen of a cliff after service

[Mooncat]

I'll give the garage the benefit of doubt and say it was just coincidence.

They might have disconnected it when replacing the air filter and not plugged it back together properly. This is something you can check very quickly yourself and is where @Spaghetti describes above. Disconnecting the MAF makes the engine operate on a different 'map' and has reduced functioning of the EGR etc but is a very good trick as a 'get me home repair' and unscrupulous dealers have been known to do this to hide other engine faults as it usually doesn't throw up an engine warning light.

 

[JOG]

Well, it was back in the garage today, brakes are fine but a fault code came up, possibly an air flow meter/ sensor. Big job?

Did this fix the issue?

 

[Scruffy]

The van goes back on Monday morning to be properly looked at. If it stops absolutely hammering down, I will have a look for the sensor and check if it has been put back correctly. Problem is where should I be looking?

 

[Scruffy]

Sorted! It was the Manifold Pressure Sensor (G71) It was showing an intermittent fault code, but after it was replaced, all's well, hopefully.

 

[Scruffy]

Hmmm, I'm not entirely sure the problem is solved. I'm yet to do a "easy" motorway run where I would expect 40+, but I've done a lot of mixed runs, headwinds, traffic, etc and I'm not getting what I would normally see. I've a few journeys coming up this weekend that should prove or not the fix.

 

[JOG]

Hmmm, I'm not entirely sure the problem is solved. I'm yet to do a "easy" motorway run where I would expect 40+, but I've done a lot of mixed runs, headwinds, traffic, etc and I'm not getting what I would normally see. I've a few journeys coming up this weekend that should prove or not the fix.

Oh, that’s disappointing. Keep us posted, please.

 

[Kind of Blue]

Hmmm, I'm not entirely sure the problem is solved. I'm yet to do a "easy" motorway run where I would expect 40+, but I've done a lot of mixed runs, headwinds, traffic, etc and I'm not getting what I would normally see. I've a few journeys coming up this weekend that should prove or not the fix.

I hope that it is, sorted. Let us hope that your run is fruitful.

 

[Scruffy]

Well, I’ve had three good trips up and down the motorway over the last few days and the mpg is way down on where it should be. I’m going to give the garage a call tomorrow and get it in again, but if the computer says no, where do we go from there?

 

[Scruffy]

Thanks to the Carista app I can now see that the van is doing a lot of regen, certainly more than one every 400 miles.I’ve done Leeds to Sheffield twice and leeds to Barnsley over the last 4 days, and the van has done a regen on some part of each journey. Any thoughts on what could fool the van into doing this? or any reason why the van suddenly needs to do this?

 

[Scruffy]

Well, sorted, finally. The rear brake callipers had failed and basically the handbrake was sticking on. They have now been replaced and I'm back to getting good mpg. The fact that the van went in for it's service performing perfectly fine, but came out with a 30% drop in mpg still is an issue which I now have to address. I'm afraid I don't believe in coincidence, the brakes were not touched by human hands since it left the factory until the discs and pads were changed on the day of the service. Something in the way the callipers were handled caused them to stop functioning correctly, and led to the problem. The initial reaction from the garage was indifference, but I'm yet to speak to the owner who did the work, so I'll let you know how I get on. If I don't get anything slightly positive from them, I will be posting on here their name, and anywhere else I can find.

 

[DaveD]

Are the brakes binding? Go for a ten minute drive then feel each wheel as close to the hub as you can. See if one feels hotter than the others?

That'll be a yes, then!

 

[Scruffy]

When I first took it in I said it feels like the brakes are on, I’ve even checked to see if the handbrake wasn’t on. Maybe I wasn’t clear enough?

 

[DaveD]

When I first took it in I said it feels like the brakes are on, I’ve even checked to see if the handbrake wasn’t on. Maybe I wasn’t clear enough?

What you said to them should have immediately made them check, I mean it's easy enough!!!
Lift each wheel in turn and see if it rotates freely, or go for a short drive as you had told them that the sensation suggested brakes sticking, you'd done half their job!
Remember, it's their job to diagnose, you pay for that expertise. You'd told them the symptoms, it wasn't rocket science.
Binding brakes was my first thought and I'm not a mechanic or expert, I think that says it all.

 

[DXX]

Any mechanic good or bad would check wheel rotation resistance after changing brake pads.
It’s possible that they didn’t adjust the hand brake correctly after renewing the rear pads.

 

[Scruffy]

Any mechanic good or bad would check wheel rotation resistance after changing brake pads.
It’s possible that they didn’t adjust the hand brake correctly after renewing the rear pads.

View attachment 94997

Funnily enough the handbrake now feels completely different to pre new callipers ( like its been adjusted correctly) .

If you were to be composing a "strongly worded" email to said garage, what questions in particular would you be asking?

 

[DXX]

Funnily enough the handbrake now feels completely different to pre new callipers ( like its been adjusted correctly) .

If you were to be composing a "strongly worded" email to said garage, what questions in particular would you be asking?

I’m not much of a diplomat, you’re asking the wrong person.
You mention new calipers, I guess the originals cooked and they thought it wise to renew, hopefully they paid.

 

[Scruffy]

Nope. £370 later, plus £130 for a air flow sensor that was faulty, apparently.

 

[Broadside]

Nope. £370 later, plus £130 for a air flow sensor that was faulty, apparently.

Personally I wouldn’t do this by email and would go in to see them to discuss it but make it very clear how annoyed I am.

9-Nov van went in with working brakes that then got replaced by them
11-Nov they checked the brakes and confirmed no issues

Late November they checked it properly and found an issue with the brakes. The excessive heat build up has probably now cooked the callipers and I expect your pads and discs are now fried as well. You told them very quickly after they screwed the brakes up, offered them the chance to correct it which they failed to do and now there’s an expensive repair.

I wouldn’t leave their office until they agree to pay for all of it. You can’t do that last bit by email.

 

[DXX]

Nope. £370 later, plus £130 for a air flow sensor that was faulty, apparently.

The Bosch MAF is 58 quid inc vat from auto doc and a few minutes to fit, I think they are taking the piss.

 

[DaveD]

The Bosch MAF is 58 quid inc vat from auto doc and a few minutes to fit, I think they are taking the piss.

You beat me to that comment.
I think the whole sorry saga suggests that this garage is one to avoid.