LFA951

I was using the Bosch Super Copper Plugs WRC7's and I pulled them out and they were black, this is probably why it was backfiring. I bought some NGK BPR6ES and immediately noticed a difference, it runs a lot smoother and no more backfiring, however, I noticed that the temperature gets hotter, almost up to the top white line when at a light. I was reading up on the threads here and alot of you guys use the 7's. I use my car for the street, it's not a daily driver and it's driven mostly on the weekends. My question is, should I switch to the 7's or keep the 6's? I have a MAF by Pro Flow Tech and the MBC boost is set to 12 psi with a 3 bar FPR and 3" exhaust with Borla muffler.

lart951

Try NGK BPR7ES , one range colder.

testarossa_td

^^^^^What he said.

Porschefile

Ditto. 7's. Running 1bar with and without a maf I used to see a bit of misfiring on the top-end with the 6's occasionally. There isn't any reason why the difference in heat range between 6's and 7's should cause your car to run that much hotter, so I think you might want to check out your cooling system to see if you have any issues there.

streckfu's

What he said.

One range on the plug won't make a difference in how hot your car runs. 'Hotter' refers to spark energy not an actual temperature.

LFA951

I have no coolant leak issues, had one two months ago, but Bar's stop leak fixed it...

streckfu's

Is that a liquid you poured into the coolant to stop leaks? If so, I bet that is your problem.

Those liquids will coat and clog the coolant passages as well as the inside of the radiator greatly reducing efficiency.

toddk911

Yep! Those pour in's are meant to be a temp fix.

Flush and drain and then find and fix the leak.

If this does not get addressed you can blow your head gasket with an overheating system.

streckfu's

It may be too late late for a flush. Once those stop-leak liquids harden, you can't clean them with a flush.

Have you seen coolant passages fof an engine that have been that crap? They look like cross section of a blocked artery; filled with a yellow-while calcium like deposits.

Bri Bro

Well not quite, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber.

eclou

Second that. Otherwise, there would be little reason with modern ignition systems to use but a single heat range. Colder plugs reduce the tendency to ping and detonate. Another trick to use is narrowing the plug gap down to .026" .

Porschefile

Sweet mother of God! I just noticed you have over 17,000 posts! Awesome. Looks like you have some catching up to do Todd!

LFA951

The temperature was fine when I had the Bosch Super WRC7's, it only chqanged when I switched to the NGK's...

Porschefile

There is absolutely no way that a spark plug can cause drastic changes in coolant temperature like that. Trust me, your problem is elsewhere and likely a very subtle one if you haven't already noticed it. My last coolant issue was so subtle that it was a pin ***** in the heater valve coolant line at the back of the block. For the longest time I thought it was my rear main leaking, though it turned out to be coolant. There are only a million other hard to find spots where these cars can leak from, so do a thorough check over the entire car. Also, are you sure your fans are coming on? Have you tried flushing the coolant system, replacing the thermo switch for the fans, etc?

hosrom_951

The factory recommends the 7 range (cold), never go to a hot range (6 and below).


BPR7ES works great, even in the hottest of climates IIRC, better than that WR7DC from Bosch.