Spark Plugs! N52

[Reamesy]

So since ownership I have been getting an average of 37.1 MPG on my runs to and from work which is 10 miles of B roads and the rest motorway. Its 165 miles so gets a good run. I use cruise control and set it to 70 once on the motorway.

Over the last two months my MPG has dropped to an average of 36.6 which I attributed to the cold weather. During lockdown I have replaced the oil cooler housing gaskets, CCV system including pipes. Two oil changes and changed the air filter.

So today I decided to change the spark plugs and coil packs as a maintenance procedure as I thought all was well. I used the Bosch FR7NPP332 with pre gap of 1.0mm.

The coil packs were the originals all but one and were the Bosch type. The replacement was Bosch grey colour and all original were a dark black/grey.

I have ordered Delphi part number 12138616153 from AutoDoc at £142.85 with delivery. These are still on route.

On my drive back up north ready for work tomorrow I averaged 39.6MPG at the same driving speed and conditions. Same fuel, same temperature, same tyre pressure.

So , don't underestimate the power of a good spark

I have beed driving diesels for the last ten years so I overlooked the importance of basics and I do know better but failed to recognise it.

 

[coupe159]

which brand did you use for the oil cooler gaskets? I need to do change mine soon too

 

[Scooba_Steve]

which brand did you use for the oil cooler gaskets? I need to do change mine soon too

Just go for BMW, £25 each or so. While you're there you might want to do the tensioner and belt.

If you won't want to take the manifold off you'll need a teeny UJ, I used this: https://smile.amazon.co.uk/gp/product/B000LFS0LU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

And a 1/4" E10.

After I did a full coolant flush (easier on the N52 with the elec pump to circulate it a few times) to ensure no oil present then changed coolant, did an oil flush and change to be sure as well.

I found a long bar for the tensioner was useful when doing it yourself, you'll need a pin if you want to lock it. A new one will come with one.

 

[Reamesy]

which brand did you use for the oil cooler gaskets? I need to do change mine soon too

I used AutoDoc website and went with Elring. £26.78 with delivery.

Or go with genuine. I changed mine due to an external oil leak. No cross contamination to note and both oil and coolant nice and clean.

 

[coupe159]

I was thinking the elring ones from auto doc too, have them in my basket currently.

 

[Scooba_Steve]

I was thinking the elring ones from auto doc too, have them in my basket currently.

Elring are probably the OEM, they certainly are for the throttle body gasket (only an example).

 

[coupe159]

I not long ago changed the tb gasket with an elring one, it did look and feel slightly different to the original. The original looked completely fine to be honest and didn't need changing really

 

[E86]

That's a long commute!

How many miles were on your plugs? Suggested service interval for plugs is 100k on the N52. The economy improvement you've seen will soon pay for a set of plugs

 

[Reamesy]

That's a long commute!

How many miles were on your plugs? Suggested service interval for plugs is 100k on the N52. The economy improvement you've seen will soon pay for a set of plugs

Been doing that commute for 10 years now. Only twice a week though as I do four on four off.

The was serviced regularly by the previous owner but not much on record keeping for items included so I just went on the side of caution. Im still waiting on my coil packs

 

[GTwice]

I've seen in the past in my cars - changing old spark plug would result in 3-4 MPG improvement.

 

[skelters]

Sounds as if you're on top of it but...

Have you checked the tyre pressure?

Throttle reset....
https://z4-forum.com/forum/viewtopic.php?f=32&t=195&p=340346&hilit=throttle+reset#p2221

Have you used different fuel at all or at least changed every few months to a tank of something else?

I do 10 miles to work, 24 - 26 mpg. Most I've had is 41.1 mpg on the motorway, new tyres, roof down, 70mph too.

 

[yipikayee]

used the Bosch FR7NPP332 with pre gap of 1.0mm.

i was looking at spark plugs on autodoc today. so the correct one for the n52 is 1mm gap? doc showing .75 gap too
in the spec both of them kinds showing compalibility with my 3.0i engine. what is the difference then?