1999 Venture Oil Pump or oil pressure switch

[joeshannallie]

Was at red light and went to pull out and oil light came on and van started missing really bad. Oil level is fine. Will start and that is it. Engine jerks really bad and it dies out. Van was running fine and this all of sudden happen with no warning. Please someone reply with some suggestions. Also is there anything specific that I need to do after I install a new oil pump?

[sergeimoskva]

Hi!
Most likely - it your oil change and filter reminder light.

[joeshannallie]

I do not think the 1999 models have that feature.

[sergeimoskva]

Hi !
Your oil change interval is 3000 miles read your manual.
I therefore recommend to change the oil and filter
But perhaps you have defective oil pump.
The light is an oil pressure light. It's good that you checked the engine oil level but I would say get it checked out just to be sure. The car has a on-board diagnostic computer which has a code for every problem so it would be easy for a GM dealer to let you know the problem.

[joeshannallie]

Please can someone else chime in on this if you have any clues of what may be wrong. The van will start and then about 10 to 15 seconds if that it will start jerking and missing real bad and dies out. I have checked the plug wires and they seem to be fine. Also can a stripped rocker arm cause the bad misfire and dieing out. If it was a rocker then I think it would make a very noticeable or bad noise, Right? I hate to do a oil pump and the the problem still be there. To me it is a major job to do. Any sure way to know if the pump has went out. Could I take the front valve cover off and see if oil is getting there. I dont know if it will run long enough to get oil up to the rockers. Should it be there almost instant when the van starts? Please reply soon.

[Blue Bowtie]

The 60° V-6 can lose a rocker arm and misfire badly without a lot of mechanical noise being generated.

This is an example I encountered. The customer drove the car into the shop about 18 miles stating is was misfiring:





That may not be the problem, but if it is there might not be any noise. In order to replace the oil pump the oil pan would be removed. It's easier to remove the rocker covers and inspect there first, and also easier to remove the spark plugs for evaluation.

[joeshannallie]

Thank you so much. The rocker arm is what I am hoping. It may be a hard fix if it is in the back but it cant be as hard as getting the oil pan off. Also the van will instantly die if you put it in drive. Also I need some advice on Heli Coil or something else. I think Heli Coil may be all that my Autozone sells. Cant really order and wait on something else. It is our only vehicle right now.

[Blue Bowtie]

Coincidentally, those two blown-out studs were in the rear bank of a Pontiac Grand Am. I used Heli-Coils (actually, Chris-Lynn) M8x1.25 inserts about 10mm deep. The kit with the tap, insertion tool and inserts was about $25.

If you discover pulled rocker studs it can be done in the vehicle. The accessories will have to be removed if it is the rear bank. This includes the alternator and PS pump, and of course the wiper mechanism on a Venture.

If you discover pulled studs, thread inserts are usually sufficient to repair the damage. Before tapping the holes for the inserts, stuff paper towels or some other material into the oil drainbacks to keep metal chips from entering the oil pan. Vacuum (do not blow) all chips out of the head area before removing the packing. The chips are not magnetic so they must be vacuumed.

If you find pulled studs, check them ALL. Remove one at a time and inspect the bolt threads closely, clean the threads (wire brush) and apply threadlocker to the last few mm of threads. Torque the bolts to 15-16 ft/lb ONLY and proceed to the next bolt.

You MUST use LocTite threadlocker on all rocker studs. 242 service-removable is a good choice for this application. This applies even to those installed with thread inserts.

Good luck. I hope it's just a plug or coil pack.

[joeshannallie]

Thank you so much. Your advice is greatly appreciated!

[Cressidaadr]

BB, are those studs broken off or is it the steel threads stripped out of the aluminum head (I think this).

Is it generally known as to why some of them fail while others seem to go the distance without issues? If unknown, what is a best guess?

When I had to do my head gaskets (3.4 engine) I don't remember any suggestion to use locTight on these studs back then. I believe it was about 14 lb ft + 30 degrees. However, I do remember not being able to readily determine 30 degrees on that back head so I just put extra torque to them so that they wouldn't loosen up. My guess was at least 45 ft. lbs. Later I remember being concerned that I over did it but so far they've been fine.

[Blue Bowtie]

For clarification, the steel bolts (not actually studs, per se) rarely if ever break. They most often pull the threads out of the aluminum head casting.

Why some go for a million miles and some don't last 150K is not completely clear, but a bulletin within ASE suggests that starting a cold Chevy 60° V-6engine with pumped-up lifters and revving it too high can contribute to bolt pullout. Using the correct, clean oil per the owners' manual, starting and warming a cold engine, and properly operating until normal temperature is achieved can make all the difference.

Incidentally, "correct oil" doesn't necessarily mean that the "5W30" imprinted on the cap is correct. The owners manual describes what the correct viscosity and type of oil is at a given temperature range, and it DOES change.

[Tech II]

I found this on a car once....the bolts pulled the threads out of the head.....but the reason was obvious......the car previously had a lower intake job done, and god only knows how those bolts were installed......

A guy next to me ran into this problem, doing an intake job......He put his air wrench on the bolts, and zipped them all out......by doing that, he took the threads out on two bolts.....NEVER zip out the rocker bolts with an air wrench......break them free MANUALLY first, then you can put the air wrench to them.....when he tried to tighten the stripped heads, he couldn't get the final torque....had to heli coil the heads.....

Sad part is, there is a special tool that can rotate the rocker, so you can pull the push rods out of the engine without removing the rocker arms...saves a lot of time.....



Your other option is to do a compression check instead of removing the valve covers...

[joeshannallie]

Boy what a job. Got the oil pan off and new oil pump installed. Old one looked fine. Will finish it up back together tomorrow. Rocker arms were fine. There was one pushrod on the front and one or two on the back that were a little loose. Maybe like the lifters had dropped(if that makes sense) just a little. Not loose enough in my opinion to cause any problems. I just have a feeling that the oil pump was not the problem. Also installed oil pressure switch and still ran the same. Start up and almost instant die because of miss. Also installed new motor mount. Old one was very worn out. Plugs are about 6 months old so I would think they are ok. Will update tomorrow.

[Blue Bowtie]

The push rods which are loose should have all their lash taken up as soon as there is oil pressure and the lifters are pumped up properly.

We're crossing our fingers for you. Hopefully your work thus far has solved the problem. Just out of curiosity, did you happen to pop off a main bearing cap or two to check their condition when the pan was removed? The lower mains (in the caps) can be very revealing about overall crank/bearing wear.

[Tech II]

Did you check oil pressure manually with a gage before doing this work?