missfiring problems
#51
11-23-2009, 07:00 AM
Join Date: Mar 2009
Location: Tokeland, Washington
Posts: 21,671
what motor? start a thread with your problem. ull get a better response from much more informed people than me. 
need more info. have u had it scanned for trouble codes? whats the oil pressure cold and at operating temp? how many miles on the car?
need more info. have u had it scanned for trouble codes? whats the oil pressure cold and at operating temp? how many miles on the car?
#52
11-23-2009, 10:45 AM
Make sure you try cleaning/replacing your PCV valve, as they can contribute to a rough idle, and they're inexpensive. I was told by a GM failure analysis guy that some aftermarket ones have issues, so get a GM one to be safe...
Document ID# 764610
2002 Chevrolet Camaro
--------------------------------------------------------------------------------
Crankcase Ventilation System Inspection/Diagnosis
Concern
Action
External oil leak
Inspect for any of the following conditions:
Plugged positive crankcase ventilation (PCV) valve.
Damaged or incorrectly installed PCV valve.
Excessive crankcase pressure.
Rough Idle, Stalling, or Low idle speed
Inspect for any of the following conditions:
Plugged PCV valve.
Leaking (damaged) PCV valve.
High idle speed
Inspect for a leaking (damaged) PCV valve.
Sludge in the engine
Inspect for a plugged PCV valve
Document ID# 764610
2002 Chevrolet Camaro
--------------------------------------------------------------------------------
Crankcase Ventilation System Inspection/Diagnosis
Concern
Action
External oil leak
Inspect for any of the following conditions:
Plugged positive crankcase ventilation (PCV) valve.
Damaged or incorrectly installed PCV valve.
Excessive crankcase pressure.
Rough Idle, Stalling, or Low idle speed
Inspect for any of the following conditions:
Plugged PCV valve.
Leaking (damaged) PCV valve.
High idle speed
Inspect for a leaking (damaged) PCV valve.
Sludge in the engine
Inspect for a plugged PCV valve
the symptoms are almost identical to mine. the problems started happening right after somebody put sand on my hood and put a couple scratches in it. I replaces the coils, had the spark plugs replaced, and the ignition module. My fuel pump went and then i replaced that. then the car still wasnt running right and i had multiple cylinder missfire. Gas started to get down into the oil. (the lifters started clicking) I had one fuel injestor replaced, but it didnt help. I finally had the rack of fuel injectors replaced. It seemed to work (the lifters were only there when cold) but it seemed rough. It didnt seem to have all the get up and go it had. There is a vibration that is almost always there. When the engine gets above a certain rpm the vibration goes away. I think the gas is getting into the oil still. i have put over $1000 into this already, i just want it fixed
Last edited by libertyforall1776; 11-23-2009 at 10:50 AM. Reason: Added GM Crankcase Ventilation System Inspection/Diagnosis
#53
11-24-2009, 09:25 AM
the engine is a 3.8 v6...the oil pressure is below what it is usually at, which is 60. The oil pressure responds to the rpms. if i give it gas the oil pressure will increase. The operating temperature never heats up. it gets to a certain point (not anywhere near where it did when i first got it) and just stops there. the car has 144k but the engine was only supposed to have 85k when i got it and have put about 10k on it.
#55
11-24-2009, 04:18 PM
Not the whole story... 10W-30 is preferred ONLY if the temp is 0 degrees Farenheit or higher, otherwise use 5W-30 for the cold winter, it it applies in your area...
From GM (Document ID# 760014):
Notice
Using engine oils of any viscosity other than those viscosities recommended could result in engine damage.
Motor oil viscosity has an effect on fuel economy and cold-weather operation (starting and oil flow). Lower viscosity motor oils can provide better fuel economy and cold-weather performance.
When choosing an motor oil, consider the range of outdoor temperatures the vehicle will be operated in before the next oil change. Then select the recommended oil viscosity.
The recommended SAE motor oil viscosity is 5W-30. However, if outdoor temperatures will remain above -18°C (0°F), 10W-30 may be used.
-----
Also:
Document ID# 55065
1997 Pontiac Firebird
--------------------------------------------------------------------------------
Lubrication 3800 F-car
The engine lubrication system is of the force-feed type. This means that oil is supplied under full pressure to the crankshaft, connecting rods, valve lifters, camshaft and rear balance shaft bearing. It also means that a controlled volume of oil is supplied to the rocker arms and push rods. All other moving parts are lubricated by gravity flow or splash. The supply of oil is carried in the lower crankcase (oil pan) which is filled through a filler opening in the rocker arm cover. A removable oil level indicator rod on the left side of the crankcase is provided to check the oil level. The oil pump is located in the front cover and is driven by the crankshaft. It is a gerotor style pump which is a combination of gear and rotor pumps. It is connected by a passage in the cylinder crankcase to an oil screen housing and pipe assembly. The screen is submerged in the oil supply and has ample volume for all operating conditions. If the screen becomes clogged, oil may be drawn into the system through the relief valve in the screen. Oil is drawn into the pump through the screen and pipe assembly, and a passage in the crankcase, connecting to the passages in the front cover. All oil is discharged from the pump to the oil pump filter adapter assembly. The assembly consists of an oil filter bypass valve and a nipple for installation of an oil filter. The spring loaded oil pressure relief valve located in the timing chain cover, limits the oil pressure. The oil filter bypass valve opens when the filter has become restricted to the extent that approximately 68.95 kPa (10 psi) of pressure difference exists between the filter inlet and discharge, to by-pass the oil filter and channel unfiltered oil directly to the main oil galleries of the engine. A full flow oil filter is externally mounted to the oil filter adapter on the lower right front side of the engine. If the filter element becomes restricted, not allowing engine oil to pass through, a spring loaded bypass valve opens. The main oil galleries run the full length of the crankcase and cut into the valve lifter guide holes in order to supply oil at full pressure to the lifters. Holes drilled from the crankshaft bearings to the main gallery intersect the cam bearing bores in order to supply oil to the cam bearings.
Oil is carried from the crankshaft bearings to the connecting rod bearings through holes drilled in the crankshaft. Pistons and cylinder walls are lubricated by oil thrown off the crankshaft and by connecting rod splash. Piston pins are lubricated by splash.
Each rocker arm and valve is supplied with oil through the tubular push rod. This oil comes from the inside of the lifter, passing around the metering valve and through a hole in the lifter push rod seat. Oil from the push rod passes through a hole in the lifter push rod seat, and emerges on top of the push rod seat boss.
From GM (Document ID# 760014):
Notice
Using engine oils of any viscosity other than those viscosities recommended could result in engine damage.
Motor oil viscosity has an effect on fuel economy and cold-weather operation (starting and oil flow). Lower viscosity motor oils can provide better fuel economy and cold-weather performance.
When choosing an motor oil, consider the range of outdoor temperatures the vehicle will be operated in before the next oil change. Then select the recommended oil viscosity.
The recommended SAE motor oil viscosity is 5W-30. However, if outdoor temperatures will remain above -18°C (0°F), 10W-30 may be used.
-----
Also:
Document ID# 55065
1997 Pontiac Firebird
--------------------------------------------------------------------------------
Lubrication 3800 F-car
The engine lubrication system is of the force-feed type. This means that oil is supplied under full pressure to the crankshaft, connecting rods, valve lifters, camshaft and rear balance shaft bearing. It also means that a controlled volume of oil is supplied to the rocker arms and push rods. All other moving parts are lubricated by gravity flow or splash. The supply of oil is carried in the lower crankcase (oil pan) which is filled through a filler opening in the rocker arm cover. A removable oil level indicator rod on the left side of the crankcase is provided to check the oil level. The oil pump is located in the front cover and is driven by the crankshaft. It is a gerotor style pump which is a combination of gear and rotor pumps. It is connected by a passage in the cylinder crankcase to an oil screen housing and pipe assembly. The screen is submerged in the oil supply and has ample volume for all operating conditions. If the screen becomes clogged, oil may be drawn into the system through the relief valve in the screen. Oil is drawn into the pump through the screen and pipe assembly, and a passage in the crankcase, connecting to the passages in the front cover. All oil is discharged from the pump to the oil pump filter adapter assembly. The assembly consists of an oil filter bypass valve and a nipple for installation of an oil filter. The spring loaded oil pressure relief valve located in the timing chain cover, limits the oil pressure. The oil filter bypass valve opens when the filter has become restricted to the extent that approximately 68.95 kPa (10 psi) of pressure difference exists between the filter inlet and discharge, to by-pass the oil filter and channel unfiltered oil directly to the main oil galleries of the engine. A full flow oil filter is externally mounted to the oil filter adapter on the lower right front side of the engine. If the filter element becomes restricted, not allowing engine oil to pass through, a spring loaded bypass valve opens. The main oil galleries run the full length of the crankcase and cut into the valve lifter guide holes in order to supply oil at full pressure to the lifters. Holes drilled from the crankshaft bearings to the main gallery intersect the cam bearing bores in order to supply oil to the cam bearings.
Oil is carried from the crankshaft bearings to the connecting rod bearings through holes drilled in the crankshaft. Pistons and cylinder walls are lubricated by oil thrown off the crankshaft and by connecting rod splash. Piston pins are lubricated by splash.
Each rocker arm and valve is supplied with oil through the tubular push rod. This oil comes from the inside of the lifter, passing around the metering valve and through a hole in the lifter push rod seat. Oil from the push rod passes through a hole in the lifter push rod seat, and emerges on top of the push rod seat boss.
#56
11-24-2009, 04:19 PM
Sounds like you better also check your cooling system: Flush, thermostat, etc.
the engine is a 3.8 v6...the oil pressure is below what it is usually at, which is 60. The oil pressure responds to the rpms. if i give it gas the oil pressure will increase. The operating temperature never heats up. it gets to a certain point (not anywhere near where it did when i first got it) and just stops there. the car has 144k but the engine was only supposed to have 85k when i got it and have put about 10k on it.
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