Question : Equinox 3400 engine swap, no oil pressure????

[andytk5]

Swapped out a burned up engine (lower intake man gasket/coolant/oil) in a 2005 equinox with a pontiac torrent 06 3400 engine and had to have the dealer do the tech II scanner deal on it to get all the sensors to work together and he was able to get it to start but then noticed there was no oil pressure, dash guage and connect oil guage tool. He also looked into the valve cover and saw no oil was pumping. The engine I swapped in was a 67,000 mile motor with good looking oil. Wondering if I need to swap out the oil pump with a new one (they wanted $1,000 to do it!!!! WTF????) since maybe the pressure relief valve is stuck, also wondered abotu the pressure switch but that doesnt explain the visible "no oil" issue.

Need some ideas here guys.. Thanks a bunch!

[60dgrzbelow0]

Depending upon a number of factors...some of which are very rare... an engine that has either been sitting for an extended period of time ...OR... been shipped over 250 miles by either rail car or "bouncy transporter" and rough handling... the oil galleries and the internal gears of the Oil Pump can go dry with almost every drop of oil draining down into the crankcase. When this happens...an oil pump can cavitate and not pump any oil whatsoever until the Oil Pump is re-primed. Oil Pumps of our designs require almost a "solid state" connection to the fluids they pump and will not evacuate any trapped air and pick up any oil without first being primed. There are several ways to do this, but sadly they don't make an Oil Pump Priming Tool for anything other than the assortment of V-8 motors on the market. For my part, I solved the problem by designing and building my own unique OPPT (Oil Pump Priming Tool) for the GM V6 660 blocks and you are welcome to copy and use this idea if it helps you. You can find the images for this unit here on my photobucket site:

http://photobucket.com/images/A%20Newly%20Designed%20%20Oil%20Pump%20Priming%20Tool%20%28OPPT%29%20for%20GM%2060*%20V6%20Engines/

Another Old Racer's Trick is to remove the Oil Pump and after disassembling the unit, pack it with plenty of clear Petroleum Jelly, re-assemble and re-torque the face plate bolts and then submerge the pick-up screen/tube into a bucket of fresh motor oil and turn the Hex Connector until the oil pours out without any air bubbles. Bolt and torque the Oil Pump Unit back inside the engine and then fill the crankcase (AND OIL FILTER) with fresh oil, remove the ICM connections and crank the engine over until you see oil percolation over the rocker arms. Then re-connect the ICM unit and fire up the engine with a jaundiced eye watching the Oil Pressure Gauge/Lights.

But these drastic solutions may not be necessary if your Oil Pump Pressure Sensor is either disconnected at the sensor wire or just plain "Tits Up". Replace it and B4 trying it out, do a complete Oil Change and remember to FILL THE OIL FILTER WITH FRESH OIL FIRST BEFORE INSTALLING IT IN THE ENGINE BLOCK. That last suggestion might allow for one less place for air to become trapped and delay the oil on its journey through the vacant oil galleries, etc. and then into the Oil Pump sunk inside the crankcase. After that... disconnect the ICM connections and crank the motor for 30-45 seconds to see if the oil can get picked up and worked into all those empty oil galleries and bone dry bearings. Hope this helps!

[andytk5]

Depending upon a number of factors...some of which are very rare... an engine that has either been sitting for an extended period of time ...OR... been shipped over 250 miles by either rail car or "bouncy transporter" and rough handling... the oil galleries and the internal gears of the Oil Pump can go dry with almost every drop of oil draining down into the crankcase. When this happens...an oil pump can cavitate and not pump any oil whatsoever until the Oil Pump is re-primed. Oil Pumps of our designs require almost a "solid state" connection to the fluids they pump and will not evacuate any trapped air and pick up any oil without first being primed. There are several ways to do this, but sadly they don't make an Oil Pump Priming Tool for anything other than the assortment of V-8 motors on the market. For my part, I solved the problem by designing and building my own unique OPPT (Oil Pump Priming Tool) for the GM V6 660 blocks and you are welcome to copy and use this idea if it helps you. You can find the images for this unit here on my photobucket site:

http://photobucket.com/images/A%20Newly%20Designed%20%20Oil%20Pump%20Priming%20Tool%20%28OPPT%29%20for%20GM%2060*%20V6%20Engines/

Another old Racer's Trick is to remove the Oil Pump and after disassembling the unit, pack it with plenty of clear Petroleum Jelly, re-assemble and re-torque the face plate bolts and then submerge the pickup screen/tube into a bucket of fresh motor oil and turn the Hex Connector until the oil pours out without any air bubbles. Bolt and torque the OPD, fill the crankcase (AND OIL FILTER) with fresh oil, remove the ICM connections and crank the engine over until you see oil percolation over the rocker arms. Then re-connect the ICM unit and fire up the engine with a jaundiced eye watching the Oil Pressure Gauge/Lights.

But these drastic solutions may not be necessary if your Oil Pump Pressure Sensor is either disconnected at the sensor wire or just plain "Tits Up". Replace it and B4 trying it out, do a complete Oil Change and remember to FILL THE OIL FILTER WITH FRESH OIL FIRST BEFORE INSTALLING IN THE ENGINE BLOCK. That last suggestion might allow for one less place for air to become trapped and delay the oil on its journey into the Oil Pump. After that... disconnect the ICM connections and crank the motor for 30-45 seconds to see if the oil can get picked up and worked into all those empty oil galleries and bone dry bearings. Hope this helps!

O so I got the thing started, I actually used your idea and took a gear oil pump for my outboards and used it to plus into the oil pressure switch port to push extra oil into the engine the oil pan began to fill up more on the dip stick. The looking at the old engine in the garage and how the pump is configured the oil would only be able to go into the pan via the oil pump and pick up. So I would assume the oil pump is full of oil now. I hooked up the oil pressure guage to the pressure switch port I just used and cranked the engine. I got somewhere between 50psi~ on the guage then I reconnected the coil packs and cranked it, smioke came out of the exhaust and the press guage popped to 50 again, so I would think it is pumping. I looked into the valve cover and couldn't see any more oil filling up in the valve area since the mech at GM said he put his finger in there and looked to see if oil was pumping, not sure about this process?

So I am popping the valve cover off to see if oil is flowing when we crank the motor over. Am I doing anything wrong or what should I be seeing in the valve area? Thanks a lot 60degreez!!!!

[andytk5]

Ok, cranked it with the valve cover off and oil was coming out of the little holes at the top of the rocker arms. I didnt know oil was pushed up the pushrods.. Cool, so that should be all good right?

[andytk5]

Cranked it up and it has a lighter colored smokey exhaust... Kinda worried its a water in the cylinder thing... what could that be? Any chance it has to do with the oil pressure guage being hooked up still and not being sealed very well? Should I pull some plugs to check inside the cylinders?

[60dgrzbelow0]

Andy... You're Welcome... The white coloured smoke indicates the burning of coolant, with the probable source being leaking head gasket(s). In addition to being a little "creaky" after sitting for so long... sometimes after being started and brought up to operational temperature, engine sealants and head gaskets will fail in motors that have not been "exercised" for quite some time, especially up north where severe winters can come and go while such unused engines sit dormant. Please make certain that your oil colour is appropriate for new motor oil and does NOT appear like a kind of chocolate-mousse-looking goo. That last image happens when intake manifold gaskets fail and liquid coolant and drains down into the crankcase, getting picked up with motor oil by the pump and breaking the down the oil lubricity as it is churned into a viscous "Chocalate Malt" mixture, causing even more havoc down below below. This is not a trivial problem because the acids and chemicals in all coolants will destroy the surfaces of soft, multi-metal bearings and in some cases, the bearings can seize on moving parts and then spin inside the block, and even snapping hollow camshafts in half, too. If your oil pressure cranked up to 50 PSI, chances are if the motor was not left running too long before a complete engine oil priming was possible, your bearing tolerances are still good. Check with others here with experience on doing the head gasket replacement unique to your vehicle and more than likely, there are some excellent posts here to guide you in this repair. By the way... there are probably a few thousand members here who would love to see the clever tools and methodology you used to "Oil Prime The Engine from the Bottom Up"... for you have come up with a Way Cool solution!

[60dgrzbelow0]

Ok, cranked it with the valve cover off and oil was coming out of the little holes at the top of the rocker arms. I didn't know oil was pushed up the push-rods.. Cool, so that should be all good right?

With the exception of later model GM V6 engines that have super efficient lifters with built in roller bearings to mate with elliptically shaped camshaft lobes, earlier versions employ what are called "FLAT TAPPET HYDRAULIC LIFTERS". In this design, the lifters or tappets have a hardened flat base on the bottom side that meets with the cam lobes on the camshaft and a sort of cup-shaped opposite end that mates up with a push-rods that are more like McDonald's Drink Straws with hardened balls welded on either ends and a hole in them to allow for the oil to be hydraulically "pumped" through. Inside the lifters are mini-plungers that act to squirt small amounts of oil upwards on each lifting motion as the oil entering the lifters is pushed up inside the hollow push-rods with each motion. This action leaves small puddles of oil coming out the other ends that mate up with the cupped ends of each rocker arm. In this way, oil under repeated pulsing pressure is gradually brought from the center main oil galleries feeding the lifters to the top of the engine (but not TOO much at a time) to provide some top end lubrication. In some cases (as per John Forced-Firebird) using an Over-Volume Oil Pump can pump too much oil into the top end of an engine at higher RPM B4 the oil can migrate back down by gravity through the center webbing drain holes to re-supply the empty crankcase with return oil. (Whew! All that for such a simple machine part! LOL) And yes... seeing oil finally coming out over the rocker arms is ALWAYS Cool.....Very Cool....