1999 V70 T5 measured spark plug gap wear

Post by **abscate** » 15 Jul 2015, 04:15

Running NGK Cu plugs with 27000 miles on them. Car was running well, but gap had grown to over 0.040 inches. Spec in manual is 0.030 inches and many here recommend 0.028.

I regapped to a tight 0.030" fit.

Thinking back I'm not sure I checked gap on plugs out of box, but that was in a long since overwritten piece of RAM.

Post by **Ozark Lee** » 15 Jul 2015, 07:46

My Bosch coppers tend to grow the gap to the 0.040 to 0.045 range after about 30,000 miles. They may do it quicker than that but I try to remember to check and re-gap them at that interval.

I have a theory about it. I think it may be a "memory" problem with the steel since the gap seems to grow back to the same point where it came out of the box, before I tightened it up when they were installed.

...Lee

Post by **cn90** » 15 Jul 2015, 09:32

Or switch to NGK BKR6EIX (Iridium) and forget about it for the next 80K-100K.
I use a bit of antiseize to prevent galling at the next change.

I installed the NGK BKR6EIX (Iridium), about $7/each at local parts store, and the car loves it.

Post by **abscate** » 03 Aug 2015, 14:18

I pull mine every 2 years or so for compression tests so gapping the cheap ones works out better on my pocketbook. At my run rate 100000 miles would be 2025

Post by **RussB** » 06 Aug 2015, 17:59

I install new Bosch coppers every spring. 10,000 or so miles

Post by **j-dawg** » 07 Aug 2015, 21:04

I regapped my NGKs from around .038 to .028. Made no noticeable difference to performance or fuel consumption.

Noooo idea how many miles were on them. Probably a billion.

Post by **erikv11** » 08 Aug 2015, 11:05

I have over two billion on a set of OEM plugs right now. So far.

Post by **abscate** » 08 Aug 2015, 13:43

No doubt zip tied in....

Sommerfeldt · Post by **Sommerfeldt** » 08 Aug 2015, 14:42

I just changed my plugs and put in a set of Volvo OEMs. Had a quick chat with the guy at the stealership, to confirm a gap of 0.03"-ish (0.75 mm). He looked bewildered and said he thought the gap was supposed to be 0.4 mm (0.015").

So I just chucked them in straight out of the box, since the dude assured me they were pre gapped.

F it. Car runs great.

- S

Post by **abscate** » 08 Aug 2015, 17:52

The North American user manual says 0.030 inches (0.75mm)

Its not confidence building when the dealer people don't know their stuff, is it? I could see a cold weather adjustment of a small amount, but not 1/2 the gap for you guys in Scandinavia