[chad67chev]

I have a miss fire on cylinder 5.. went to change spark plug.. had oil all over it... what does this mean?

 

[basscatt]

Re: oil on spark plug..

I have a miss fire on cylinder 5.. went to change spark plug.. had oil all over it... what does this mean?

----------------
that means the seal is weeping a little -
not unusual - and usually not a problem

 

[Submariner409]

Re: oil on spark plug..

Yep ^^^^ The plug wells are sealed with O-rings in the cam covers. Over time they tend to weep. Oil is an insulator, so if the metal shell and up the boot is slimy it's not usually a problem - and how many miles did it take for you to discover the oil ? :lildevil:

I got anal and did the plugs in my 2002 at about 60,000 - two plugs were a little oily. Oh, well .............. it runs just fine.

What car, year, engine, mileage ???? Please update your profile - it helps with diagnosis, and the info DOES make a big difference.

 

[chad67chev]

Well i just got the car... it has 152,000 mi on the car... the top part and ceramic part didn't have oil... the threads and diode had oil on it.... where the spark plug sparks had oil on it as well... i don't know how it would be able to make a spark covered in oil like that.... as far as i know that is the only cylinder like that.... can i replace the o- ring...... how do i know it's not the piston ring or valve guide?

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Its a 2000 deville dts. 152,000... i don't have any history info on it...i know it shows a miss fire on cyl 5 in my scanner... it just look like to much oil on the plug

 

[MoistCabbage]

The oil was on the plug, in the well, above where it seals against the head. When you removed the plug, the oil dripped down onto the rest of the plug.

 

[Ranger]

Remember, it took 13 years to accumulate that oil in the plug well. If you are really worried about it (I wouldn't be), pull 'em every couple of years ans clean 'em out.

 

[chad67chev]

Oh ok... that makes sense...i replaced the plug and boot.. still miss firing.. any ideas

 

[Ranger]

Please update your profile to show your year so we don't have to ask or search. I see from post #4 it's a 2000 (COP ignition). Might be a bad ignition coil, but that's in the ignition cassette and is not serviceable. You'd have to replace the cassette, but first try a good TB cleaning.

 

[MoistCabbage]

Is it still misfiring after the plug change?

Did you clean or replace the plug boots?

 

[basscatt]

Oh ok... that makes sense...i replaced the plug and boot.. still miss firing.. any ideas

----------------------
you said you have a misfire on #5 -
I assume you had a P0305 code - correct?

with the new spark plug and boot -
we can take those out of the equation -

that leaves a failed fuel injector - or failed ignition coil -

to rule out the injector - use a stethoscope -
or a long handle screwdriver directly on the injector -
with the engine running - you should hear the injector clicking -

to be sure the problem is the ignition cassette -
swap the front and rear cassettes -
YES - they are identical - except for the color -

if the misfire changes to #4 - the problem MUST be the coil -

 

[chad67chev]

Wow ok.. thanks for all the info i will take a look tonight and see what i can find out

 

[chad67chev]

Ok so i used the screw driver method on the fuel injectors...they all make that consistent ticking noise so i think they are all working...im starting to think its my coil...

 

[Ranger]

im starting to think its my coil...

Probably so, but don't overlook a good TB cleaning first. That's free and believe it or not, can cause a rough idle.

 

[chad67chev]

I actually cleaned the tb today. Still same problem...i seen coils on ebay for 100.00 and up.. compared to oriellys 300.00........ are they the same? Id rather spend less money...

 

[basscatt]

I actually cleaned the tb today. Still same problem...i seen coils on ebay for 100.00 and up.. compared to oriellys 300.00........ are they the same? Id rather spend less money...

-----------------------------
Deville - Seville - and Eldorado - all use the same coil cassettes -
and all coil cassettes are the same - except for color -
you can but the gray one in the back - and the black one in the front -
or two gray ones - or two black ones - it just doesn't matter -

there are several manufactures -
Delphi is an OEM supplier - and of course ACDelco is an OEM supplier -

you can get brand new Delphi units for $200 or less with free shipping on ebay -

there are several aftermarket brands -
STANDARD brand makes a lot of automotive electronic parts -

but these parts really are reliable -
and you can save a ton by getting used parts -

check your local junk yard -

 

[Ranger]

:yeah: Junkyard. Generally speaking they are pretty reliable.

 

[chad67chev]

so... i just purchased a used coil pack of a 2000 cadillac deville that is in good working condition or money back on ebay..... paid 64.75 for ir.. im guessing thats a good deal, right?.. should be here in a few days.. ill let u guys know what i find out

 

[CadillacLuke24]

Hey, if you can get your money back sounds like a decent deal.

 

[chad67chev]

so.. i installed the newly bought (used) coil casette.... now my car runs great.. the missfire is gone... thank you all for the help

 

[Ranger]

:thumbsup: Cool! Thanks for the feedback.