I had began to notice unusual engine vibrations. After first start of the day, it would act like it was going to shut off while backing out. But ran ok for the rest of the day.

Then a few days ago started having trouble getting my car to start. Had spark(per timing light), had fuel(40, per guage),timing marks good, injectors pulsing. No codes. No start!

It started after awhile, and sputtered and acted like it was running on less that four clyinders, then smoothed out a bit.

Changed spark plugs, using ngk BPR6ES. Problem appears to be gone. Car running stronger that it has in awhile.

I have lurking in my mind that this could still be some kind of intermittent freak, but, for a couple of days I had this problem, especially on the cold wet morning(sacramento, 4 days of rain), now it starts right up and runs like a banshee.

The tips of the bosch platinums(27,000mi) that I took out were not fouled. A bit on the dark side, but not far from normal looking. (I gotta get that camera). They were, however, hard to get out. Did I use thread lock by mistake, instead of the copper anti sieze that I usually use? I dont know. But it was a tussle.
Didnt hurt the threads.

Thanks you All

1990 volvo 240 non turbo 207,048 miles

Bosch platinums are garbage because of the design with that tiny little nub of platinum.
NGK platinums may be better, but NGK coppers are just downright fantastic.

With all the high mileage Volvos that we read about and own, an awful lot run on plugs installed by a dealer tech. These plugs say Volvo on them (or Ford, like the original plugs in our '08 XC70)

I'll bet that Irv Gordon uses Volvo plugs! (I'll ask him the next time I see him)

Volvo could use any plugs that they please - their reputation relies on them!

And yet, people try to second guess Volvo all the time.

Did you look at the spark of the worst looking plug outside the car?

Darkness could be fouling - put an Ohm meter on them? If the plugs got hot enough, they could have metal deposits on them.

If you have access to a plug blaster, you might clean them to see if the car runs better after cleaning - an old-time shop might clean them for a small fee.

I hear you.
I never did eyeball the spark. The timing light told me that ignition was working. At that point I pulled all the plugs just to get an idea of what was going on. I broke one getting it out. So, looking for the easy solution,I installed the ngks. Car is now starting and running very well. My fear of an intermittent situation has been disproven. Something was wrong with the plugs.

Your idea of have the plugs cleaned and tested is a good one. I will look into that.

Thanks for the response and input.

Thanks brickboard.

Larue

Hello,

I have similar issues for Bosch platinum plugs. They installed great runs great but didn't last according to advertised claims. My take is that the platinum electrode is fitted flush with the porcelain centre part. The platinum tip is very small in diameter, about half a millimetre or less. Slight fouling on the tip would obscure that part causing weak spark performance. Some engines runs great with platinums but not our redblocks.

If you prefer high performance plugs, choose the ones with exposed metal electrodes such as the Iridiums and others similar. For me I would stick to copper plugs all the time.

Thread locking compounds are not commonly used during plugs installation. It may hinder the electrical grounding contacts for the plugs. Anti-seize is occasionally used instead but you must ease up a bit on the torque as anti-seize lubricates the plug threads. Anti-seize contains some copper and aluminium flakes which didn't interfere with electrical contacts as much. The best is to install the plugs dry.

Regards,

Amarin.

i'm a pro and have run into this all the time, and not just Volvo's. I love bosch coppers but why they insist the plats are better, i'll never know. never use ANY plats in anything. best thing I install them into is the trash can. good luck, chck.

I have no idea why, but in the 14 years reading this board I hear over and over to avoid the platinum plugs. No problem for me -- the only platinum I own is in my cat. Copper NGKs recommended ad infinitum.
--
Art Benstein near Baltimore

Beauty is only a light switch away.

I have read here the platinum plugs and red blocks don't get along.
Dan