Hi, this is my first post here. I just bought a ‘95 850 Turbo wagon, to replace my 84 DL. In getting oriented to my “new” car, I’ve explored 4 or 5 Volvo forum sites. Just this once, I’m cross-posting this message to two of ‘em, Brickboard and Matthew’s, to gauge which site I might like to hang out at more often. ;-)

The question in brief: is it possible that the presence of water in a single plug well could indicate that condensation is somehow occurring? If so, could such condensation be somehow related to the plug gap being too wide?

More detail: When I bought the 850 Turbo, it felt like it was missing on one cylinder and the Check Engine Light was on (not a deal breaker, when the deal was $1200 for a ‘95 with 140k miles, otherwise in pretty nice shape). This being my first-ever car with any sort of onboard computer, I had fun figuring out how to read codes -- which indicated a misfire on cylinder #4. Indeed, when I lifted up the boots on each of the plugs, the #4 plug well was full of water; the other four were all dry. All boots appear to seal fine, giving me the sense that the water had somehow condensed inside. (It wasn’t gas.)

After wicking out the water, I pulled plug #4. It looked fairly new, but the gap measured .040 (in). I re-gapped it to .028, dabbed on a bit of anti-seize, and put it back in.

The car started and idled fine, no missing. So I reset the A2 codes, clearing the CEL. I’ve since driven it a few miles and it’s purring fine. I’ll put some silicone grease on that boot #4 soon, before the next rain anyway, just to rule out that possible source of water.

So where did that water come from? Is it possible that a plug gapped too wide (.040) could create conditions producing condensation? Is there some physics in these newfangled Volvos that I don’t yet understand? Or am I hot on the heels of discovering the elusive secret of Cold Fusion? ;-)

Otherwise, why would there be water in only one of five wells?

Meanwhile, a few incidental comments: Before doing the above, I tried to buy new plugs at two different parts stores (both reputable). Neither was sure which plugs I should be using; neither had Volvo OEM, and it seems Bosch is in the process of changing its numbering system(?) So I came home with two sets, representing the two shops’ best guesses: Bosch Superplus 7955 and Champion Copper Plus 344 RC9YC. It turned out the currently installed plugs are NGK, labeled R BKRGE. Any comment on whether either of the new sets would be an appropriate replacement?

Incidentally, there’s a code list appearing in various forms on several websites/forums that doesn’t seem to be entirely accurate, when compared to Volvo’s Pocket Data Booklet. For instance, it presents three sets of codes for different systems (Phoenix, etc.), but attributes the wrong set of codes to the 850 Turbo. Other who are just learning about codes (like me) would do well to track down the Pocket Data Booklet.

Thanks for any and all comment,

Kraig