940 spark plug preference on turbo? Standard or uprated?

[ukvolvo]

I have ordered a set of twin electrode iridium denso plugs for the 940...And im having second thoughts after reading about so many people using standard.

Im sure this is a well researched area so what's peoples thoughts?

Mick

[griston64]

Originally Posted by ukvolvo

I have ordered a set of twin electrode iridium denso plugs for the 940...And im having second thoughts after reading about so many people using standard.

Im sure this is a well researched area so what's peoples thoughts?

Mick

Volvo genuine or NGK. It won't like those Carlos Fandango plugs

[Jebus]

Volvo Genuine work the best, are not expensive either unless you have very specific need to change them with how it is tuned etc save the money for other bits

[Laird Scooby]

What Mark said ^^^^^

Unless the engine is pretty modern and designed for mutil-electrode plugs, they're of no real benefit.

Iridium plugs tend to be 3-4 times the cost of standard plugs and although they last longer in service, won't last 3-4 times longer in a red block or any contemporary engine.

As such, for a red block or similar, a waste of money.

Same applies for LPG plugs for the red block and similar aged engines, mainly because most LPG rated plugs are generally Iridium but have a couple of other minor tweaks to justify "enhancing" the price a bit.

With so many "genuine" Volvo parts being out-sourced (red block water pumps are a good example) to cheap, Chinese made sources, i tend to avoid Volvo genuine for a lot of things. For spark plugs i'd always go for NGK as i've never had a problem with an NGK plug.

Volvo genuine oil filters are still good though!

[360beast]

Ngk bpr6es

[classicswede]

NGK are good dependable plugs. BPR6ES is good for most cases. If you are running a over 1 bar boost you could think about going to BPR7E or you can use BKR7E if you want the smaller head.

Genuine Volvo plugs are good. They are made by Bosch but to Volvo spec. I know when you read that the Volvo part is not the same as the part offered by the company that makes it that the statement comes over as BS but in this case that is true.

I prefer to always keep to a single prong plug, this can be important if re gapping is needed

KISS - Keep It Simple Stupid is often best

[Forrest]

The last set of plugs I put in my B200FT were Bosch WR6DC. I chose these because that is what the owner’s manual said to use and I was having trouble with it at the time. They are still running well a year on.

Volvo OEM equivalent to the above are 270747, now superseded by 272464.

Volvo 270746 are also sometimes listed as suitable for these engines. These are still available and are equivalent to Bosch WR7DC, a hotter plug than the WR6DC.

[Clan]

Originally Posted by ukvolvo

I have ordered a set of twin electrode iridium denso plugs for the 940...And im having second thoughts after reading about so many people using standard.

Im sure this is a well researched area so what's peoples thoughts?

Mick

you wont get a better spark plug than the volvo ones ..

[Laird Scooby]

Originally Posted by Clan

you wont get a better spark plug than the volvo ones ..

Once upon a time i would have agreed with you but as noted elsewhere in the thread, they're made by Bosch, albeit to (allegedly) better standards than the rest of what Bosch make.
I've noticed in general Bosch have been getting poorer in quality in recent times and in fact, i recently bought a NOS Bosch rotor arm (and dizzy cap) on ebay for my beast. I was astonished at the amount of flashing on the moulding, all of which needed cleaning off (came off easily enough, should have been done at the factory though) or it would have prevented the rotor arm mounting properly on the dizzy shaft. Someone else may not have noticed or worried about this and potentially had problems as a result. The point is, if there QC is letting things through with excess flashing, what else are they letting through?

In recent times (past 8-10 years) i've noticed a lot more misfiring Bosch plugs, even with correctly set gaps.

I've only found 4 misfiring NGK plugs and the gaps were ~1.3mm, representing 60-70k miles since they were last changed. Cleaned and regapped and the misfire was gone - they've since been renewed though.

I think they had every right to be misfiring a bit when they were that far past their useful life so even those 4 can't really be counted.

Also i later found an invoice from the plugs being supplied and fitted at ~60k miles (and 10 years!) previously which substantiated my theoretical 60-70k miles that they'd been in. As the receipt was from a relatively local Volvo "specialist" it would be nice to think they set the gaps correctly and didn't just leave them at the NGK factory-0.9mm gap.

Interesting to note though that an independent Volvo specialist was fitting NGKs in preference to Volvo plugs 15 years ago though.

[griston64]

Originally Posted by Laird Scooby

Once upon a time i would have agreed with you but as noted elsewhere in the thread, they're made by Bosch, albeit to (allegedly) better standards than the rest of what Bosch make.
I've noticed in general Bosch have been getting poorer in quality in recent times and in fact, i recently bought a NOS Bosch rotor arm (and dizzy cap) on ebay for my beast. I was astonished at the amount of flashing on the moulding, all of which needed cleaning off (came off easily enough, should have been done at the factory though) or it would have prevented the rotor arm mounting properly on the dizzy shaft. Someone else may not have noticed or worried about this and potentially had problems as a result. The point is, if there QC is letting things through with excess flashing, what else are they letting through?

In recent times (past 8-10 years) i've noticed a lot more misfiring Bosch plugs, even with correctly set gaps.

I've only found 4 misfiring NGK plugs and the gaps were ~1.3mm, representing 60-70k miles since they were last changed. Cleaned and regapped and the misfire was gone - they've since been renewed though.

I think they had every right to be misfiring a bit when they were that far past their useful life so even those 4 can't really be counted.

Also i later found an invoice from the plugs being supplied and fitted at ~60k miles (and 10 years!) previously which substantiated my theoretical 60-70k miles that they'd been in. As the receipt was from a relatively local Volvo "specialist" it would be nice to think they set the gaps correctly and didn't just leave them at the NGK factory-0.9mm gap.

Interesting to note though that an independent Volvo specialist was fitting NGKs in preference to Volvo plugs 15 years ago though.

My nearest Volvo independent doesn't use any genuine Volvo parts

I think it's more down to price than quality though