2007-09-23 06:16:32 · 4 answers · asked by Don B 1 in Cars & Transportation ➔ Car Makes ➔ GMC
The motor has just had the valve seals done, and compression is 135 across the board.There is no blue smoke, and uses about 6 litres of oil per tank of gas
2007-09-23 06:26:31 · update #1
Because it's a 350. Usually, the valve guides in the head just wear out, assuming the heads have never been rebuilt. The rings on the pistons are probly getting worn, too. My 350 w/150k used a quart every 1k miles, so it's typical. Even 454s and 305s do the same. Usually, redoing the heads will solve it. Just because you cant see it coming out of the exhaust pipe doesnt mean it's not happening.
2007-09-23 06:22:25 · answer #1 · answered by nn200404 3 · 1⤊ 2⤋
Oil is either being sucked down the valve guides, or the oil rings on the pistons are bad. With that much compression the oil is being burned very efficiently, and ashless dispersant oils don't smoke that much anyway. I had a truck that would use a gallon of oil in about 300 miles and it didn't smoke. All the oil rings were completely worn out.
2007-09-23 08:18:11 · answer #2 · answered by eferrell01 7 · 1⤊ 1⤋
So you are saying that your vehicle uses over a gallon and a half of oil in 300-400 miles? And there is no smoke and no leaks? I find that virtually impossible! It's either going out the tail pipe or winding up on the ground, those are really the only 2 options. So it's either burning the oil or leaking it.
2007-09-23 14:07:27 · answer #3 · answered by Mr. Badwrench 6 · 1⤊ 1⤋
it sounds like you have a valve guide problem it sounds like you need a valve job
2007-09-23 07:06:21 · answer #4 · answered by scott U 1 · 1⤊ 1⤋