spark plugs SHOT...oil too...humm

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digitaldrifter91

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hey there well i finally got around checking my spark plugs. i wonderd why my gas milage went from 320 to 220 miles a tank.

i took out the spark plug and really...wow. the top thing that shoots down current is worn, kinda corroaded but more of rust. the electrode cannot be found, and it has a little black stuff on the ring of the base of the plug.

these are bosch platnum's and been in my car for 2 years, about 25to 30k on them.

also on #2 i have oil on the spark plug itself. i always saw oil in the spark plug hole but never thought it would be on the plug itself. i know its my little valve cover o-ring i really hope thats the problem, imma seal it with rtv this time.

i will be going NGK for once to hope to see everything go better than when these plugs were new.

i looked at spark plug pictures, and it seems it is worn, its running too hot, and has carbon deposits. my car ran great though...aside from MPG. no wonder i notice a stutter at times when its idling.

dunno.gif
 
I think if you change the plugs you will cure your problem. sounds like the platinums are just worn out. Some engines just don't work well with these plugs.
 
I'm working from memory, but I think rust-colored deposits on plugs indicates MMT fouling.

I agree with staying away from platinum plugs unless they're specified for your engine.
 
Be sure you do not have a water leak into the cylinder. This can clean the electrodes right off the plug. In fact, it cleans everything else off the cylinder, which is how you know you have a leak in that cylinder; the cylinder will have no carbon deposits. Also, an undertorqued plug can seep oil aroung the base, as well as overheat, causing a burned appearance of the electrode. Find the original equipment plug type from the owners' or shop manual and use only those plugs. Finally, gap the plugs, torque them to spec, using a little graphite anti-sieze, not the aluminum-powder kind, and hope for 100K this time.
 
quote:
Originally posted by digitaldrifter91:
hey there well i finally got around checking my spark plugs. i wonderd why my gas milage went from 320 to 220 miles a tank.

i took out the spark plug and really...wow. the top thing that shoots down current is worn, kinda corroaded but more of rust. the electrode cannot be found, and it has a little black stuff on the ring of the base of the plug.

these are bosch platnum's and been in my car for 2 years, about 25to 30k on them.

also on #2 i have oil on the spark plug itself. i always saw oil in the spark plug hole but never thought it would be on the plug itself. i know its my little valve cover o-ring i really hope thats the problem, imma seal it with rtv this time.

i will be going NGK for once to hope to see everything go better than when these plugs were new.

i looked at spark plug pictures, and it seems it is worn, its running too hot, and has carbon deposits. my car ran great though...aside from MPG. no wonder i notice a stutter at times when its idling.

dunno.gif

Click to expand...
wow, dude. I'm in the same boat as you. I've got bosch platinum in my car for the past three eyars and 20k miles. my gas mileage has gone down the tank from 360 miles to 270 miles. It's gotten about 240 miles in the winter. I thought maybe my oxygen sensor was getting lazy, but now I think I should check the plugs! my car runs good though ,I did have an idle problem that I solved by cleaning the throttle plate with carb cleaner.
 
Does your can have a DIS? Bosch platniums have a pure platnium electrode which is known to wear down very quickly with high power ignition systems, like GM uses. You'd be lucky getting 10,000 out of them.

Try a good planium plug like AC delcos. Bosch platniums are junk.

-T
 
wow thanks for the replies dudes. whats DIS?

my car is a I4 engine...fuel inejcted of course =).

well i should try and take a pic later of the plugs. for now i bought some OEM ngk at kregan. honda wanted the same one for 3 bucks more...!!

im wondering about that oil on that one plug...did the oil get sprayed on there or the oil from the top that was in the hole just coverd it when i took it out....

it was pretty clean oil though.

i wonder if i service that ring and put RTV..should i replace them all incliding the seal for the valve cover or can i re-use it? i really dont feel like buying anything any more haha.
 
i changed the plug for now. what a difference in acceleration on WOT. it idles quiet...and doesnt have that "bogg"

next week ill take it out again and possibly seal the valve cover better.

what torque settings should i use? i used a wrench and made it slightly tight, then just a little more...o and i put anti seis on the threads.
 
Just an experience note. Bosch plugs and Japan design motors don't mix.
The first thing we looked for in our shop when having trouble was Bosch and Splitfire plugs.
Splitfire really seem to be bad in GM engines.
Just 2cents worth
Smoky
 
DIS= distributorless ignition system. GM started it in the early 80s, most GM cars had it by the late 80s. Other makes started a bit later, but most on the market today have it. Bosch plugs wear down quickly with high power ignition systems and should be avoided all together. The only worse plug I've seen are Champions. AC and NGK are always a good bet.

-T
 
quote:
Originally posted by Smoky14:
Bosch plugs and Japan design motors don't mix.
Click to expand...
Uh, maybe that statement is just a bit too general. I care for 5 Subarus, 7 if you count the 2 we've sold. In 5 of those 7, when it was time to replace the OE plugs, I replace them with Bosch +4 plugs. On one '97 (the one that's had them the longest, 59,000 miles so far) the car is STILL telling me that when I decide to replace these plugs, it wants the same flavor! The others like them just as much, just not as many miles on them (average 25,000 to 35,000).

Dave
 
quote:
Originally posted by n8wvi:

quote:
Originally posted by Smoky14:
Bosch plugs and Japan design motors don't mix.
Click to expand...
Uh, maybe that statement is just a bit too general. I care for 5 Subarus, 7 if you count the 2 we've sold. In 5 of those 7, when it was time to replace the OE plugs, I replace them with Bosch +4 plugs. On one '97 (the one that's had them the longest, 59,000 miles so far) the car is STILL telling me that when I decide to replace these plugs, it wants the same flavor! The others like them just as much, just not as many miles on them (average 25,000 to 35,000).

Dave
Click to expand...
It's obviously brand dependant. There are a lot of reports of Bosch platinums giving a check engine light on late model Toyotas after a few hundred to a few thousand miles. Going back to the stock ND or NGK plugs always cures the problem.

Over the years I've found in unmodified engines the factory brand and heat range of plug seems to work best long term. My Ford gets Motorcraft, Toyotas and Nissans get NGK or ND, etc...
 
Bosch single (not +4) platinums have given me excellent service in Ford and GM big-bore, low-rpm truck engines. Autolite platinums give up early. Just my experience.

High rpm European and Japanese engines are a lot more picky and OEM design plugs are a must. My BMW likes NGK, but it is the special design for that car, dual side-electrode, similar to some Mazda and Toyota designs.
 
I've run the ND and Bosch Plat +4's in my 2.4L tacoma engine and just put in a set of NGK, "V-Groove" plugs that are OEM approved.

I'd stick with the NGK's ...I didn't like the way the bosch plugs looked after 35,000 miles, compared to the ND's. The antisieze is very important, as it's also a thread sealant and keeps combustion gases from gradually loosening the plug. The two plugs on my engine closest to the firewall had both loosened up to just past finger tight, and I was getting sooting on the spark plug leads.
frown.gif
This is the noise I thought was coming from the solid lifters, which are now as quiet as ever. No wonder my fuel efficiency had dropped by about 10%! Yeah, yeah, I should have known better ....

You can use a torque wrench, but the antisieze with affect how easily the plug turns. I prefer the hand tightening method, then 1/2-2/3 turn with a small socket wrench. Go slow and you can feel when the plug gasket has the right degree of compression. It's very close to 1/2 turn w/ my toyota engine ....

Tooslick
 
when i tightened it...it was weird. like ill tighten it by hand..it will stop..then i use my wrench but it would still be going...so i turned it like an oil filter, slowly until its snugg...

after i took it off to see how hard it would be, it took little effort...is this ok?

i say i turned it at least 3 or 4 times before it was snug. if i were to use a torque wrench it would of been near the same.
 
4 to 5 turns? Are the threads stripped?
shocked.gif


Bosch Plus 4 didn't work well in my Audi engine either. I had no problems with the OEM NGK three prong plugs. The Bosch Plus 4 have a tiny platinum electrode that just fries away. There's a reason why Bosch does not list this plug for my car. Maybe it's similar with the Honda.

[ February 19, 2004, 08:20 PM: Message edited by: moribundman ]
 
they dont seemed stripped...i took one out...

i think cause when i hand tighten it...its not tightening all the way but let me try a torque wrench now.

i have the torque spec in my book.
 
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