After Dynoing the car several times and always getting low low numbers decided to change spark plugs to see if there were any problems there.
Well the old ones were fould, they where almost black.... what does that mean?
Also I had some oil leak there from the valve cover gasket... spark plugs where dirty in oil when we took them out, Could that be the reason why the spark plugs where black?
Changed the plugs for Denzo Iridium Plugs, and wow! The car feels totally different (I hope its not only my imagination) feels way smoother and way more powerful. I will dyno soon again to see if we solve the problem.
After Dynoing the car several times and always getting low low numbers decided to change spark plugs to see if there were any problems there.
Well the old ones were fould, they where almost black.... what does that mean?
Also I had some oil leak there from the valve cover gasket... spark plugs where dirty in oil when we took them out, Could that be the reason why the spark plugs where black?
Changed the plugs for Denzo Iridium Plugs, and wow! The car feels totally different (I hope its not only my imagination) feels way smoother and way more powerful. I will dyno soon again to see if we solve the problem.
Sounds like oil fouled your plugs. Black and wet is usually oik, if black and dry, usually too rich, white indicates too lean. You want a nice light brown/tan color. Car prob feels better because you do have new plugs, but if they are not factory, can't tell if any benefit. If you buy some OEM plugs, you can dyno back to back and then see if there is any difference.
Regards,
Jerry
the Denso's will make little difference with a N/A application in the M5 but do help a little with idle quality and off idle throttle response. Where you will see big differences is in a fully prepped engine. I have also heard some people say that they gain about 1% better gas mileage with them in as well.
The reason that you see such a huge difference in power is due to the fact that you just have new plugs in the car. Glad to hear that you car is back to its starting point.
its possible that the oil leak could have been shorting out a plug (or more). When I took mine out, they had a brownish, kind of mocha color to them. I posted pics here, if you want to compare. My local shop said they looked perfect.
Look forward to dyno results. Have you tried to clean your MAFS yet?
Mike
its possible that the oil leak could have been shorting out a plug (or more). When I took mine out, they had a brownish, kind of mocha color to them. I posted pics here, if you want to compare. My local shop said they looked perfect.
Look forward to dyno results. Have you tried to clean your MAFS yet?
Mike
havent cleaned the mafs yet, I havent gotten any codes since clearing them last time, wonder how long will it take to clean the mafs, if I can do it quickly then, I can do it b4 the dyno. Gordon wanted me to bring the car at lunch time to dyno it. Do you guys think that I should let the car adapt to the plugs? or is not necessary?
This is a pretty informative web page on spark plugs. http://www.centuryperformance.com/spark.asp There is a second page as well that has some images on it for "reading" spark plugs.
I'm going to change mine this weekend and see what they look like. I'm using NGK.
I just hit 55k, From what I heard from Samir (Im sure you know who Im talking about) , he told me to go witht he denso he said those were the best barnone. He said they use the denso on all their cars and all teh supercharged cars too.
I just hit 55k, From what I heard from Samir (Im sure you know who Im talking about) , he told me to go witht he denso he said those were the best barnone. He said they use the denso on all their cars and all teh supercharged cars too.
After Dynoing the car several times and always getting low low numbers decided to change spark plugs to see if there were any problems there.
Well the old ones were fould, they where almost black.... what does that mean?
Also I had some oil leak there from the valve cover gasket... spark plugs where dirty in oil when we took them out, Could that be the reason why the spark plugs where black?
Changed the plugs for Denzo Iridium Plugs, and wow! The car feels totally different (I hope its not only my imagination) feels way smoother and way more powerful. I will dyno soon again to see if we solve the problem.
The oil on the outside of the plugs will not help, especially if it has seeped into the insulating boot and is allowing an alternate path for the electric spark. I had this situation on my 525 where the plug tube was "filled" with oil. Replaced valave cover inner gasket.
As far as the plugs being black, I don't have enough experience to tell, but if the cylinder was misfiring, or partially firing, that could explain it.
Dunno if the M5 suffers this prob but on each of my e36 M3s I would have needed to replace the plugs every 1500/2000 miles as each car developed a very slight miss at low RPM. I contacted a respected tuner (Bexely motor works) and they informed me that this was quite common on M cars and that I should be glad I didnt have an Evo model as the coil packs do the same on them
Dyno'ed.... better numbers but still low... 320whp... the graph doesnt look as choppy... not sure if the coils are ok... will have the coils checked at the dealer next week.... will also check all the sensors.... this is so frustrating....
As for the plugs...the car feels great def an improvement from before, car feels stronger and has a better iddle.
Denso Iridium I think are still made in Japan. The NGK Iridium are made in California.
Platium is twice the money for twice the life, never seen any performance increase. I've used NGK V-power for the longest time and still do on some engines.
I am impressed with the Iridium plugs strong lasting fine wire, this should give long strong life.
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