98 C3500 using oil

stacyj · 06-12-2007, 01:43 PM

I have a 98 C3500 with the 7.4l engine. It has 101,000 miles on it and has been rebuilt as a result of a dim-witted mechanic working on it and dropping a screw driver bit into one of the cylinders. Both heads have been machined and now I am using about a quart of oil about every 1K miles. Does a 454 normally use that much oil routinely after only 100K miles or am I burning it up somewhere? No noticable leaks underneath around the pan or plug. I think that this is excessive.

mrjohnwayne · 06-12-2007, 02:12 PM

did they completely rebuild the motor or just remove the heads to fish out the bit? It depends on the vehicle. some don't use any oil with high miles and some use alot. do you notice smoke out of the exhaust at start up or when driving down the road.

ddraszt · 06-12-2007, 09:17 PM

was it burning that much before the "rebuild"??? I wonder if they rebuilt the heads? Most common ways to lose oil are worn rings, leaky valve stem seals, or of course the black spot left in the drive way. If it were me I would pull the plug in the cylinder that there was the issue with and see if it has signs of oil leakage into the combustion chamber.

75K30 · 06-13-2007, 02:32 PM

An engine that uses that much oil is called a diesel!
All kidding aside, is it possible that you just have a bad PCV, and engine vaccum is drawing oil out of the engine, or something minor like that?

scottie · 06-13-2007, 07:21 PM

yeah, check the pcv and valve seals. if one of those umbrella seals poped off, your oil would be dumping straight into you cylender via the valve

stacyj · 06-15-2007, 06:41 AM

I'll have those things checked. It did not burn that much oil before the rebuild and that is my concern. The entire motor was torn down and rebuilt, the heads were also machined. New rings were also installed.

NCroadracer · 06-19-2007, 10:35 PM

If it was just completely rebuilt....It is normal to use that much oil until a proper break in is achieved. The rings need to seat and that takes about 500 miles. After that it should decrease the consumption. If it continues at that rate it could be valve seals, PCV problem, or even the rings themselves could be installed incorrectly indexed.

06-12-2007, 01:43 PM	#1
stacyj Junior Member Join Date: Jun 2007 Posts: 2	98 C3500 using oil I have a 98 C3500 with the 7.4l engine. It has 101,000 miles on it and has been rebuilt as a result of a dim-witted mechanic working on it and dropping a screw driver bit into one of the cylinders. Both heads have been machined and now I am using about a quart of oil about every 1K miles. Does a 454 normally use that much oil routinely after only 100K miles or am I burning it up somewhere? No noticable leaks underneath around the pan or plug. I think that this is excessive.

06-12-2007, 02:12 PM	#2
mrjohnwayne Senior Moderator Join Date: Apr 2005 Location: Texas Posts: 3,792	did they completely rebuild the motor or just remove the heads to fish out the bit? It depends on the vehicle. some don't use any oil with high miles and some use alot. do you notice smoke out of the exhaust at start up or when driving down the road. __________________ John Wayne 2000 F-350 7.3L Powerstroke 4x4

06-12-2007, 09:17 PM	#3
ddraszt Full Member Join Date: Jun 2007 Location: arlington wa Posts: 43	was it burning that much before the "rebuild"??? I wonder if they rebuilt the heads? Most common ways to lose oil are worn rings, leaky valve stem seals, or of course the black spot left in the drive way. If it were me I would pull the plug in the cylinder that there was the issue with and see if it has signs of oil leakage into the combustion chamber. __________________ "It is what it is"

06-13-2007, 07:21 PM	#5
scottie Senior Member Join Date: Jan 2006 Location: South Florida (Palm Beach), originally from south of BOSTON Posts: 644	yeah, check the pcv and valve seals. if one of those umbrella seals poped off, your oil would be dumping straight into you cylender via the valve __________________ im a straight shooter with upper management written all over me

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06-13-2007, 02:32 PM	#4
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	An engine that uses that much oil is called a diesel! All kidding aside, is it possible that you just have a bad PCV, and engine vaccum is drawing oil out of the engine, or something minor like that?

06-15-2007, 06:41 AM	#6
stacyj Junior Member Join Date: Jun 2007 Posts: 2	I'll have those things checked. It did not burn that much oil before the rebuild and that is my concern. The entire motor was torn down and rebuilt, the heads were also machined. New rings were also installed.

06-19-2007, 10:35 PM	#7
NCroadracer Senior Member Join Date: Apr 2007 Posts: 306	If it was just completely rebuilt....It is normal to use that much oil until a proper break in is achieved. The rings need to seat and that takes about 500 miles. After that it should decrease the consumption. If it continues at that rate it could be valve seals, PCV problem, or even the rings themselves could be installed incorrectly indexed.

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