Hi,
1) Subject = '95 Olds, 3800, Series II engine.
2) Last fall I changed the lower intake manifold gasket at 70,000 miles.
3) I noted two oil pool; one on the passangers side, back corner, and the other on the drivers side front corner. I changed the plenum gasket, but not the plenum.
4) Because the plenum was a bit warped, and due to the "EGR burn through problem", I decided to change the plemum. I did this last week, and noted the same two oil pools.
5) The intake manifold passages are wet, that is, are coated with oil.
6) I bought the car last fall, only to find that it cosumes approx. one liter of oil in 2500 miles.
7) First Question: Is this pooling of oil in the manifold normal for these engines?
8) Second Question: Could this be where my oil is going? The engine is not leaking oil, and there is no visible smoke. The oil can only get to the combustion zone (A) through the rings (B) down the valve guides, or(C)through the PCV circuit.
9) It seems like a bumb design, another GM fumble of the ball. For decades engines have been designed with PCV circuts that do not trap or pool oil. The flow of the air into the crankcase and out again is designed in a way that permits any excess oil to flow back to the crankcase.
10) I had a '94 Olds, Series I, 3800 that at 135,000 miles, would not consume a liter of oil in 7000 miles. The PCV valve on my '94, 3800 was located near the throttle body, and I never had the Plenum (aluminum) off the see if there were puddles of oil in the manifold. Perhaps there were!
10) I put on a Dorman plenum with the inproved EGR tube fix. I noted that the Dorman plenum had a somewhat smaller hole just below the PCV valve. The original hole was approx. 0.315 inch dia. and the Dorman PCV entry hole dia. was approx 0.220. I wonder if this was done intentionally, to reduce the flow in the PCV circuit.
11) Third Question: Do these engines have ring coking (carboning) problems as does the 1.9 liter Saturn engine. I read that the 3800 went through two ring tension reductions; one approx '88, and another approx. '93. Also the piston was shortened along with the connecting rod in the Series II engine. It makes me wonder if the engine designers have not gone to far in their attempt to squeeze more efficiency out of these engines, at the expense of reliability and life. For its size, and powere, the 3800 definitely gets good mileage, and is noted for such.
Thank you
Porterhouse6
1) Subject = '95 Olds, 3800, Series II engine.
2) Last fall I changed the lower intake manifold gasket at 70,000 miles.
3) I noted two oil pool; one on the passangers side, back corner, and the other on the drivers side front corner. I changed the plenum gasket, but not the plenum.
4) Because the plenum was a bit warped, and due to the "EGR burn through problem", I decided to change the plemum. I did this last week, and noted the same two oil pools.
5) The intake manifold passages are wet, that is, are coated with oil.
6) I bought the car last fall, only to find that it cosumes approx. one liter of oil in 2500 miles.
7) First Question: Is this pooling of oil in the manifold normal for these engines?
8) Second Question: Could this be where my oil is going? The engine is not leaking oil, and there is no visible smoke. The oil can only get to the combustion zone (A) through the rings (B) down the valve guides, or(C)through the PCV circuit.
9) It seems like a bumb design, another GM fumble of the ball. For decades engines have been designed with PCV circuts that do not trap or pool oil. The flow of the air into the crankcase and out again is designed in a way that permits any excess oil to flow back to the crankcase.
10) I had a '94 Olds, Series I, 3800 that at 135,000 miles, would not consume a liter of oil in 7000 miles. The PCV valve on my '94, 3800 was located near the throttle body, and I never had the Plenum (aluminum) off the see if there were puddles of oil in the manifold. Perhaps there were!
10) I put on a Dorman plenum with the inproved EGR tube fix. I noted that the Dorman plenum had a somewhat smaller hole just below the PCV valve. The original hole was approx. 0.315 inch dia. and the Dorman PCV entry hole dia. was approx 0.220. I wonder if this was done intentionally, to reduce the flow in the PCV circuit.
11) Third Question: Do these engines have ring coking (carboning) problems as does the 1.9 liter Saturn engine. I read that the 3800 went through two ring tension reductions; one approx '88, and another approx. '93. Also the piston was shortened along with the connecting rod in the Series II engine. It makes me wonder if the engine designers have not gone to far in their attempt to squeeze more efficiency out of these engines, at the expense of reliability and life. For its size, and powere, the 3800 definitely gets good mileage, and is noted for such.
Thank you
Porterhouse6
