Volkswagen Mark IV Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
60 Posts
Discussion Starter · #1 ·
Hello all, having been an owner of a Toyota Corolla T-Sport for the last 3 years, changing to a new job means long distance commuting. I had to say goodbye to the CTS and now I'm an owner of an 53' reg Golf TDI PD with 71K miles I bought from a VW dealer. I made sure it had the timing belt changed before I picked it up last week. That's when my first encounter with trouble began. I thought the economy returned would be around the 55mpg region having seen some posts in the forum. Unfortunately, I'm getting 45mpg and if I drive like a granny, just hit 50mpg.... I've searched the posts and it appears that the MAF maybe the culprit. And so, I rang the dealer and got it booked in for a check and diagnostic next week. When I mentioned that the MAF could be faulty, it was dismissed without any hesitation by the service chap!!! He just said that there's VW has no such problems!!?? Now I'm really confused and was considering getting a MAF replacement and also having it re-mapped/chipped by chipped UK. Do you think these would help improve the fuel economy?? Thanks in advance!!
 

·
Registered
Joined
·
43 Posts
To be honest, 45mpg sounds pretty normal to me - thats about what i get. You could get 55mpg on a run, or if you drove at 56mph all the time, but surely there's more to life [:D]

Suppose you could try changing the MAF (and yes they are a common problem), but i don't see the big problem with 45mpg
 

·
Registered
Joined
·
8,293 Posts
Absolutely no way, not in a million years have you got a faulty MAF with that mpg. A faulty MAF gets you about 25mpg if your lucky.

Baz
 

·
Registered
Joined
·
4,743 Posts
Hang on though, I've read posts on here saying that the maf can go slowly over time so you don't notice it so much. What if that's the case here. Don't worry about VW service mate, they're a bunch of fools (whenever you go in, be as polite to them as they are to you, read your warranty carefully and stick to your guns!), they know the maf is a common problem, but they are trying to save the expense of changing it. There is a way to check the maf using the vag-com computer program - you could check the section oin this site to see if anyone's near you with it and willing t help.

Do you have any flat spots, or hesitations whilst accelerating? That would be a more definite indication of a maf problem.

Be aware that chipping the car may invalidate vw's warranty, though I don't think chippeduk remaps are traceable anyway, though I could be wrong about this!
 

·
Registered
Joined
·
8,293 Posts
There is absolutely nothing wrong with that MAF. And a hesitation during acceleration would more likely be an EGR issue.

Baz
 

·
Registered
Joined
·
3,956 Posts
There is absolutely nothing wrong with that MAF. And a hesitation during acceleration would more likely be an EGR issue.

Baz
Thats a very bold statement there. Please enlighten me what EGR issue would cause hesitation ?

There could well be something wrong with the MAF. They can and do fail very gradually. Mine did.

Unfortunately it is very difficult to prove to the dealer that the MAF is faulty. There is / are other current thread(s) on here discussing this, search under a forum member called Arin who is having exactly the same problem, just got car and the dealer doesn't seem to be interested.

Tricky one, especially as you've just got your car(s) You and Arin and are having these problems. The last thing you would want to do is to fork out yet more cash. However for the sake of ?70(ish) you could get an exchange MAF from VW and then at least have piece of mind.
 

·
Registered
Joined
·
8,293 Posts
The EGR valve is a butterfly valve. It's controlled by a solenoid. When the solenoid sticks it can suddenly make a jerky movement instead of a smooth one. So it'll effectively slam the valve open (or shut in some cases) causing a sudden change in air pressure. Been there and had that problem and it's playing up again at the minute. I need to get it took out and have a look at the solenoid.

The MAF can go over time which is normal in all cars, but 45mpg is normal as well. If you are in any doubt give the platinum wire a clean with isopropyl and a cotton bud and it should take any dirt or grime off it and it'll be as good as new.

Baz
 

·
Registered
Joined
·
244 Posts
Iv got the PD150 and I get anout 44mpg going back and forward to work and about 55mpg ish on a run I olso tried 1 of them ?30 plug and play chips off ebay the mpg went to 65mpg going to work and back then 57mpg on a run but was realy realy smokey when cold so I took it off and could possibly be putting it back on in the summer unless some 1 says it will fcuk up the belovid pd150
 

·
Registered
Joined
·
3,956 Posts
The EGR valve is a butterfly valve. It's controlled by a solenoid. When the solenoid sticks it can suddenly make a jerky movement instead of a smooth one. So it'll effectively slam the valve open (or shut in some cases) causing a sudden change in air pressure. Been there and had that problem and it's playing up again at the minute. I need to get it took out and have a look at the solenoid.

The MAF can go over time which is normal in all cars, but 45mpg is normal as well. If you are in any doubt give the platinum wire a clean with isopropyl and a cotton bud and it should take any dirt or grime off it and it'll be as good as new.

Baz
The EGR isn't a butterfly valve, it is more like a piston valve. It cannot fly open and shut. Perhaps you are mistaking this for the anti shudder shutdown valve, which is a butterfly type valve.

Both valves, the EGR and anti-shudder are vacuum actuated and there default states are open for the anti-shudder and closed for the egr.

Also with regard to maf cleaning, I did this every in the belief it would help, I even wrote a how-to on it. The fact is, it does nothing, whatever happens when you clean a maf is a placebo effect whereby you believe things are better. They won't be.
 

·
Registered
Joined
·
8,293 Posts
The EGR valve is a butterfly valve. It's controlled by a solenoid. When the solenoid sticks it can suddenly make a jerky movement instead of a smooth one. So it'll effectively slam the valve open (or shut in some cases) causing a sudden change in air pressure. Been there and had that problem and it's playing up again at the minute. I need to get it took out and have a look at the solenoid.

The MAF can go over time which is normal in all cars, but 45mpg is normal as well. If you are in any doubt give the platinum wire a clean with isopropyl and a cotton bud and it should take any dirt or grime off it and it'll be as good as new.

Baz
The EGR isn't a butterfly valve, it is more like a piston valve. It cannot fly open and shut. Perhaps you are mistaking this for the anti shudder shutdown valve, which is a butterfly type valve.

Both valves, the EGR and anti-shudder are vacuum actuated and there default states are open for the anti-shudder and closed for the egr.

Also with regard to maf cleaning, I did this every in the belief it would help, I even wrote a how-to on it. The fact is, it does nothing, whatever happens when you clean a maf is a placebo effect whereby you believe things are better. They won't be.
I see what your saying - sometimes cleaning it helps and other times it's just too far on.

As for the EGR - www.TDICLUB.com Go to the TDI FAQ and look for trouble shooting and go to the part where it mentions shuddering and jerky behavior. The EGR valve is basically the same type of flap as a throttle body. I'm thinking of ditching mine for a straight piece of pipe as it's function is unnoticable anyway.

Baz
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #14 ·
Thanks guys for your helpful input. My car is booked in today as we speak for an inspection and diagnostic checks. As a matter of fact, I refilled this morning with Shell V-Power Diesel and noticed improve economy and performance. I suspect the injectors may have been clogged with muck over the last 71K miles before I got it. Will keep you guys updated on the progress.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #15 ·
Well, got my car back today from the dealer. I must admit that I was really disappointed!! They don't even give a hoot about the problem at all, just saying that they've reset the electronics and test drove under hard acceleration and the returned economy was 50mpg!! What a load of bull!! When I got into my car whilst at the dealer, I checked the trip computer and it gave like 43mpg for a 6 mile test drive. Absolutely utter disappointment. So here's my verdict on the Vindis VW in Cambridge, avoid them at all cost!! I've also had some suggestions from colleagues at work and they suggested adding additives to clean up the injectors. And so I'll have a go at them this weekend and see what turns up...
 

·
Registered
Joined
·
158 Posts
I don't think you've got a MAF problem either. I've got a 130 PD Bora and it averaged 52mpg combined driving, until the weather turned cold. Then average mpg dropped to 45-46mpg. On a longer run at an average of 70 mph (I never exceed 70, honest!) it usually averages about 60mpg and this is corroborated with fill ups.

With the mild weather we've had over the last couple of days I checked again,and it returned 53 mpg today on the trip home (22 miles combined driving).

The MAF in my car has done nearly 97K.

One of the most obvious signs of a faulty MAF is a drop in performance, either throughout the rev range or it might just get to say, 3000 rpm and then not want to go any further, this is usually coupled with poorer mpg. If the stealer drove it for 6 miles under hard acceleration and got 43mpg average, I'd say your car is pretty damned good!

Hope this helps.
 

·
Registered
Joined
·
1,884 Posts
hi i have a gt tdi 115 golf i drive 24 miles to work and 24 miles bk. im currently averaging around 42-44 mpg. the roads are mainly back roads. and normally only get to abput 65 mph. i thoguht it might have been better as i dont rag me car about. do i have a problem with my maf or not?

thanks rob
 

·
Registered
Joined
·
8,293 Posts
I've said it already (more than once) - there is nothing wrong with your MAF or mileage.

Baz
 

·
Registered
Joined
·
8,293 Posts
hey, that was my first post in this thread someone had a similar post baz ok lol
Hi rob, I should have made it clearer - my response was aimed at the OP.

Cheers

Baz
 
1 - 20 of 25 Posts
Top