Kristopher

I'm curious as to the potential consequences of using a spark plug recommended for the BEL engine code on the APB.

www.ngk.com
BEL selection http://www.ngk.com/results_app.asp?aaia=1423460
APB choices http://www.ngk.com/results_app.asp?AAIA=1383038

I've heard the BEL has the POS integrated into the coil.
For what it's worth, my particular application has had both POS units replaced with BERU. The resistance of these measured differently than the Bosch units but they're apparently fine to run.

Would the BKR6E(S) plugs be a completely bad idea in the APB from an electrical engineer's perspective?

Kristopher

I just checked ETKA which seems to suggest the POS are the same between the 2002 and 2004. Both references were for the APB, mind you. I didn't see a spark plug or POS reference for the BEL.

Kristopher

For what it's worth I thought I'd reply to myself in case I never come back to this thread.

I finished installing NGK BKR6ES plugs (standard copper electrode) along with a BERU POS (to eliminate a P0300/P0301) and so far so good. The BERU cured the misfire and I did the plugs because there were BKR7E installed before. The car is stock.

In all, it doesn't appear the plugs are causing any immediate codes. I never really expected them to. If they fail I'll post back. Gap is .032"

edit: oh, and only one casualty...my last 10mm socket.

allroaddave

Maybe if you didn't use so many acronyms we'd understand what the heck you were talking about?

Me - I don't know BEL from APB, but I always assume the mfr knows what they're doing when they spec a sparkplug for their car, and tend to use what the mfr suggests - especially if it's an unmodified car.

I think what you're saying is that your coil packs were changed to a different brand and you wondered if going to a different brand or number (heat range?) on the spark plugs would be OK?

I've never been a big fan of BERU plugs, since the days when they used to come OEM on BMW's and we'd have to change them to get the car to start so we could unload them off the truck. I'm sure they're better now, but old prejudices are hard to break!

Bottom line, is the plug you used a different heat range than what was originally specc'd, or just a different brand?

Kristopher

haha Sorry,

I guess what it boils down to is the mfr recommended plug was a platinum. NGK makes several varieties, yet for 2002 (APB engine code) only one is 'recommended' being the platinum.

If you look at NGK's site you'll notice that in 2004 (BEL engine code) there are several choices. Two being the BKR6E and BKR6ES which are your basic copper electrode plugs.

Now that that's straight, the only differences I could find between the two engine codes were the BEL used a different coil and POS (power output stage aka ignitor / amplifier / ignition module...) than the APB.

Was it just a case of ignition system resistance that was the deciding factor on the spark plug recommendation?

To add to the confusion, the BERU replacement POS units have a different resistance to the Bosch, yet both are perfectly suitable for both the APB and BEL designs.

Just supposing that it won't matter in practice, but I'm curious as to why the basic BKR6E & ES plugs weren't an 'option' for the earlier 2.7T.

(The reference to the heat range was simply that it was the plug that I removed. For whatever reason the previous owner used a 7 instead of the 6)

allroaddave

OK, I think what you're asking is it OK to use the copper (cheaper I assume) plugs in an engine that originally called for the Platinums?

Again, I tend to go with what the OEM called for.....

That said, if you don't mind changing them again if you get a miss or poor performance/short life, what can it hurt, assuming they're approximately the same heat range......

Kristopher

Just a small update. The P0300 and P0301 is gone with the copper plugs. The different POS/ICM/ICU didn't seem to make a difference neither did the 'non-spec' plugs. The slight hesitation at part throttle is gone as well and overall power seems to be restored.

Kristopher

I'm going to change the plugs sometime this summer and came back to this thread to remind myself which plugs I used.

So far I've had no issues with the copper NGK BKR6ES units.
And although the links I quoted above showed differing plugs for the two different engine codes in the allroad, I just found http://www.ngksparkplugs.ca/part-finder.cfm that shows the engine codes don't matter. Where the ngk.com site offers the option of the standard BKR6ES the canadian one does not.

Depending on how well these plugs have survived I may replace them with the same number or try some of the pricier platinum, dbl plat, or iridium plugs.