help reading my sparkplugs - The 1947 - Present Chevrolet & GMC Truck Message Board Network

roadking · 04-24-2004, 08:56 PM

im getting a little bit of oil residue at the base of the threads opposite of the electrode end, plugs seemed to be burning clean otherwise. motor specs.: gm 350 crate 1200 miles,HEI, plug gap 45*, timing 10 btc. i know oil on plugs can be a sign for valve and piston ware but this is a new motor that i properly broke in, just wondering if alittle residue is normal. engine is running great.

boilrman · 04-24-2004, 10:09 PM

if you have oil on the threads closest to the wire boot, seems to me you have a valve cover gasket leaking. If you were burning oil it would turn the electrode black.

krue · 04-24-2004, 11:00 PM

Look in the back of any Hayne's Manual and there is a spark plug TS guide with pretty good pics.

roadking · 04-24-2004, 11:23 PM

boilrman this oil is coming from inside the cylinder head (very light residue) ive looked in my chilton and other manual, this is not covered in the reading plug section??

krue · 04-24-2004, 11:42 PM

Can you post some pics? It would help.

boilrman · 04-24-2004, 11:43 PM

wouldnt think valve stem seals are bad with that few miles. Compression test will tell you whether it is valves or rings

bigjimzlll · 04-25-2004, 03:28 AM

http://www.gnttype.org/techarea/engine/plugs.html

roadking · 04-25-2004, 09:47 AM

bigjim, ive looked at about 10 read your plug chart an i dont see anything similar to my plugs, my plugs are not getting oil fouled, there is no oil on or around the electrode. i will try changing my pvc and a compression check and go from there. engine is under warranty so im just kinda keeping an eye on it for now but as i said earlier engine runs and sounds great with no signs of any problems so maybe this is just a bad pvc? oh yea, i will be buying a digital camera in the near future.

greasemonkey · 04-25-2004, 11:10 AM

Make sure your plugs are screwed in tight enough. If they aren't, the compression can blow some of the fuel mixture past the threads, and it looks remarkably like sticky oil on the threads. You might notice it leaking out of the plug holes as well.
I torque mine to 25 ft-lbs.

04-24-2004, 08:56 PM	#1
roadking Registered User Join Date: Nov 2003 Location: kc Posts: 229	help reading my sparkplugs im getting a little bit of oil residue at the base of the threads opposite of the electrode end, plugs seemed to be burning clean otherwise. motor specs.: gm 350 crate 1200 miles,HEI, plug gap 45*, timing 10 btc. i know oil on plugs can be a sign for valve and piston ware but this is a new motor that i properly broke in, just wondering if alittle residue is normal. engine is running great. __________________ 71 C10 SWB BLACK AND WHITE 350 CRATE TH350 ENJOY LIFE

04-24-2004, 10:09 PM	#2
boilrman 70 Chevy 3/4t Join Date: Sep 2000 Location: Kokomo,IN USA Posts: 1,230	if you have oil on the threads closest to the wire boot, seems to me you have a valve cover gasket leaking. If you were burning oil it would turn the electrode black. __________________ Find a job you love and you'll never have to work a day in your life. 1998 Yamaha V-Star 650 1970 Chevy 3/4t, I6 (rebuilt), 4 speed Kokomo,IN

04-24-2004, 11:00 PM	#3
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Look in the back of any Hayne's Manual and there is a spark plug TS guide with pretty good pics. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

04-24-2004, 11:23 PM	#4
roadking Registered User Join Date: Nov 2003 Location: kc Posts: 229	boilrman this oil is coming from inside the cylinder head (very light residue) ive looked in my chilton and other manual, this is not covered in the reading plug section?? __________________ 71 C10 SWB BLACK AND WHITE 350 CRATE TH350 ENJOY LIFE

04-24-2004, 11:42 PM	#5
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Can you post some pics? It would help. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

04-24-2004, 11:43 PM	#6
boilrman 70 Chevy 3/4t Join Date: Sep 2000 Location: Kokomo,IN USA Posts: 1,230	wouldnt think valve stem seals are bad with that few miles. Compression test will tell you whether it is valves or rings __________________ Find a job you love and you'll never have to work a day in your life. 1998 Yamaha V-Star 650 1970 Chevy 3/4t, I6 (rebuilt), 4 speed Kokomo,IN

04-25-2004, 03:28 AM	#7
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	http://www.gnttype.org/techarea/engine/plugs.html __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

04-25-2004, 09:47 AM	#8
roadking Registered User Join Date: Nov 2003 Location: kc Posts: 229	bigjim, ive looked at about 10 read your plug chart an i dont see anything similar to my plugs, my plugs are not getting oil fouled, there is no oil on or around the electrode. i will try changing my pvc and a compression check and go from there. engine is under warranty so im just kinda keeping an eye on it for now but as i said earlier engine runs and sounds great with no signs of any problems so maybe this is just a bad pvc? oh yea, i will be buying a digital camera in the near future. __________________ 71 C10 SWB BLACK AND WHITE 350 CRATE TH350 ENJOY LIFE

04-25-2004, 11:10 AM	#9
greasemonkey Registered User Join Date: Dec 2001 Location: Pace, FL Posts: 2,155	Make sure your plugs are screwed in tight enough. If they aren't, the compression can blow some of the fuel mixture past the threads, and it looks remarkably like sticky oil on the threads. You might notice it leaking out of the plug holes as well. I torque mine to 25 ft-lbs. __________________ 1942 Master Deluxe 1969 C/10 1985 Blazer CUCV 1987 Jimmy 2004 Tahoe 2005 Silverado 1500 2005 Silverado 3500



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