VW Golf Onboard computer reads low (Golf TDI mk4)

On my Mk4 VW Golf TDI PD150 I've noticed that the onboard computer fuel economy (MPG) is showing very low on the dashboard as part of the multi-function display. The dashboard seems to generally be showing around 15MPG lower than the actual fuel consumption.

Measuring the fuel economy by calculating miles travelled for fuel used gives a much better MPG compared to the computer reading low. The maximum MPG on the computer is around 40mpg yet the calculation from fill ups gives over 50mpg tank to tank.

Initially I thought that there was a problem with the car and that the TDI was using much more fuel than I was expecting. However after a fill up it appears that the MPG fuel consumption is around the expected amount and the onboard display is wrong.


VW Golf Onboard computer reads low (Golf TDI mk4)

I've not yet worked out where the MPG figure is calculated from but the good news is that the car appears to be returning the expected good miles per gallon that I've seen in previous VW Golf TDI cars.

How To: Removing Seat Covers from VW Golf Mk4 for Cleaning/Washing



The rear bench seats in my VW Golf Mk4 TDI were getting rather dirty so I decided it was time to give them a proper clean.  It is a similar process to remove the headrest covers for washing as shown in the video below:

Removing the seats from the car is quite easy with 2 hook clips under each seat that need to be unclipped to release the seat.

Once done the seat base can easily be removed from the car.

You can see the hook clips on the base of the seat in the photo above. To remove the seat cover you need to remove the plastic clips that hold the cover onto the metal frame. If you feel underneath the edge of the seat material you will feel a plastic rod that needs to be pulled out from under the metal frame.

Repeat this process around all sides of the frame and the main part of the cover will come off in one piece.

The seat cover above is almost off and is just retained by 4 metal rods clipped into the foam.

The metal rods clip in at each end via a hook of metal. If you unclip one end the entire rod can be removed. The rod threads through a pocket in the fabric and can be slide out of that pocket so the seat cover has no metal retainers left in it.

Repeat this process with the other 3 metal rods and the seat cover fabric can then be removed from the foam base. With the larger wider bench seat there is an additional rod which also needs to be removed.

Once the metal rods are removed from the seat fabric you will be left with the cover and the seat base with metal frame and thin black foam liner as in the photo above.

The seat base with the fabric cover removed. You can see one of the metal rods removed showing on the left hand side of the foam base.

What temperature do car seats need to be washed at?

The seat covers can then be washed in a normal washing machine at 40 degrees with detergent. They come up brilliantly afterwards and look like new - much better than trying to Vax them insitu.

To refit the covers is the reverse of the procedure above. Reclipping the metal rods can be a little tricky but is easier with a second pair of hands to assist.

VW Golf Mk4 - Where are the Seat Airbag Connector Locations?

VW Golf Mk4 - Where are the Seat Airbag Connector Locations?

The connections for the front seat are located beneath each seat base and can be accessed by removing the seat. This can be done by unscrewing the rails, moving the seats back and the unbolting the seat using the bolt located at the front centre of each seat base.

Depending on the age of your VW Golf the seat airbag connectors may be different as can be seen from the photos below.

VW Golf Mk4 - Where are the Seat Airbag Connector Locations?

VW Golf Mk4 - How to find Seat Airbag Connector Locations?

VW Golf Wheel Arch Liner Replacement

When replacing the shock absorbers on my VW Golf I found that the wheel arch liner was damaged so ordered a replacement from Ebay to fix it.

Having removed the liner I was amazed to find out how much debris had accumulated behind it! Once the liner was completely off I scraped out the mud and dirt which was a considerable pile in the washing up bowl once I had finished. The dirt was very damp so hopefully removing it will stop that developing into rust and corrosion on the bodywork.

VW Golf Wheel Arch debris behind Liner

VW Golf Wheel Arch Liner Replacement

VW Golf Wheel Arch Liner - Replacement waiting to be fitted

Mud from behind the wheel arch liner on VW Golf

VW Golf Wheel Arch Liner once debris cleaned out

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VW Golf TDI N75 Boost Pressure Control Valve Replacement

I have been having some problems with the VW Golf TDI PD150 being a little sluggish at lower revs. As the car has well over 200,000 miles on it I decided that it would be worth doing a N75 Boost Pressure Control Valve replacement to see if it improved the situation - with that kind of mileage I figured the valve could benefit from replacement anyway.




The N75 boost pressure control valve is situated to the rear of the engine bay bolted to the bulkhead. There are two bolts that need to be released to remove the N75 valve.

VW Golf TDI N75 Boost Pressure Control Valve Removal

VW Golf TDI N75 Boost Pressure Control Valve Replacement

 Once the bolts are undone the N75 Boost Pressure Control Valve can be removed, the hoses uncoupled and the replacement fitted. Securing the replacement is the reverse procedure.

Close up photo of VW Golf TDI N75 Boost Pressure Control Valve Replacement

Once fitted the sluggish performance had not been resolved but the throttle response seemed much sharper and the acceleration more responsive. Next step is checking the vacuum lines for any leaks.

VW Golf TDI Real World Fuel Economy - What MPG can you get from PD150 TDI?

There are often comments that the advertised fuel economy for cars doesn't match the real world economy that drivers get on every day routes. There is also the suggestion that you need to by Eco cars or ones like the Toyota Prius in order to get good fuel economy.

 

In some cases that may be true but the real world fuel economy from the VW Golf TDI Mark4 is exceptional and beats most so called Eco cars yet at a fraction of the cost. As you can see from the dashboard shot below my VW Golf TDI with 239,228 miles on the clock is still returning excellent fuel economy. The car has done 336 miles on just under half a tank which will equate to almost 55MPG for the full tank getting over 600 miles on around 50 litres of fuel.

 

The VW Golf Mk4 TDI PD150 and PD130 are understandably considered a fantastic car with longevity as well as great fuel economy & Miles per Gallon.

 

What is the real world fuel economy for the VW Golf TDI?

VW Golf GT TDI GTI Badges - What do the Red I Badging colours mean?

There is a lot of confusion over the badges that appear on VW Golf mk4 TDI cars as there is so much variation. What do the colouors on the badges on the VW Golf Mk4 TDI signify?

My car is a VW Golf Mk4 with 150 bhp GT TDI PD engine and the badge on the back is purely GTI as below:

 mk4 gt tdi badging

Yet most expectations are that GTI only appears on a PETROL VW Golf not a diesel. On a petrol GTI the red I signifies that it is the turbo charged version.

For the Golf Mk IV TDI models the 150PD can also appear with the badge showing GT TDI or TDI all in red - there doesn't seem to be any pattern!

TDI - all in silver 90/100bhp

TDI - 110 bhp

TDI - red DI PD 115 or PD 130bhp

TDI - red TDI PD 150bhp

GT TDI - PD 150 bhp

GTI - red I, either 150 bhp petrol or 150bhp diesel TDI PD