Technical New JTD diesel fuel filter improves economy?

[Argonought]

There's been a recent post to suggest that changing the fuel filter has made quite significant improvements to mpg on a JTD

Now, I can easily understand how performance might be improved but I simply can't work out how a new filter might improve economy. There doesn't seem to be any supporting evidence on the web either.

On the hand if there's any truth in it then it's a very cheap option :idea:

Anyone have any experience or opinions of this?

 

[OzMoSiS]

my economy was on a slump so i was hoping that a full service would cure it.

an air, oil, fuel filter later..........







no change

 

[PNL]

my economy was on a slump so i was hoping that a full service would cure it.

an air, oil, fuel filter later..........







no change

Alway the case when you have a heavy right foot..

 

[john55]

It can make a difference on some cars. I know on derv Nissan Terano's and mavericks, clean the fuel filter is the usal way to stop smoking/ poor economy and low power. These do however have a mechanical pump and are not common rail. It is something to do with a slight imballance in pressure between the feed and return diesel pipes from the tank upsets the pump.
My stilo is giving slightly lower MPG than I think it should (41mpg average ) so I am going to change the filter just incase and see what happens.

 

[Argonought]

My stilo is giving slightly lower MPG than I think it should (41mpg average ) so I am going to change the filter just incase and see what happens.

Well done

I'm sure you'll find a cheaper filter than me too

 

[john55]

Well done

I'm sure you'll find a cheaper filter than me too

Back round the corner to the motor factors at lunch time. They probably wont have one in stock, but will find one and have it for me by the end of the day. They are a small local company, give very good service and have good prices too.

 

[stilosporting]

my fuel filter was changed 9000 miles ago and im still getting at least 47pmg average according to the trip computer?

 

[OzMoSiS]

my fuel filter was changed 9000 miles ago and im still getting at least 47pmg average according to the trip computer?

i take it you only coast in your car then!

 

[stilosporting]

i would call it mixed driving

although being honest i drive more aggressively than the average joe so im impressed with the return.

 

[pieandapint]

How do you go about changing the fuel filter in a JTD? Am I right in thinking fuel pressure has to be released before unscrewing the old filter?

How would I release the pressure? Start the engine and pull out the fuel filter relay/fuse?

Regards
Dave

 

[Hellcat]

Fuel filter in on the low-pressure system. Just unscrew it.

 

[john55]

Fuel filter in on the low-pressure system. Just unscrew it.

No pressure to release. It is a messy job and you will spill diesel everywhere. I found it easier to disconnect the pipes, undo the 2 bolts and take the filter mounting off with the filter, then separate them out of the car. The water sensor on the bottom of the filter is much easier to get on/ off with the whole thing lifted out.

 

[pieandapint]

And what about clearing any air in the fuel system? Is that bled using the drain plug on the base of the filter?

Regards
Dave

 

[john55]

And what about clearing any air in the fuel system? Is that bled using the drain plug on the base of the filter?

Regards
Dave

No, just leave the key on for a minute before starting. The pump should clear any air out and refill the filter. you may get a couple of rough starts or it may stop after starting due to an air bubble but it soon clears.

 

[pieandapint]

No, just leave the key on for a minute before starting. The pump should clear any air out and refill the filter. you may get a couple of rough starts or it may stop after starting due to an air bubble but it soon clears.

OK, thanks for that. I'll let you know how I get on

Dave

 

[nidza]

This is so unlogical that filter changes mpg at all... It might cause issues, but I'm not sure that it can improve anything.

 

[stilosporting]

No pressure to release. It is a messy job and you will spill diesel everywhere. I found it easier to disconnect the pipes, undo the 2 bolts and take the filter mounting off with the filter, then separate them out of the car. The water sensor on the bottom of the filter is much easier to get on/ off with the whole thing lifted out.

this is what the garage did when they replaced mine.

 

[Argonought]

Doing it that way is the Fiat recommended procedure (from eLearn)

It might look long winded but sounds like it works out easier in practice