'90 2.4 oil pump replacement

[royster]

The information I’m sharing here is intended to be a supplement to the technical manual you should be working from. I performed this task using a Haynes manual, and a lot of common-sense. I find the Haynes manual isn’t too “beginner~friendly” and this is why I chose to produce this thread: to share what I learned, and to clarify steps which are vague or missing in the manual. For those who just want to keep their trucks running good, a repair like this is likely something you‘ll only do once, if it‘s done right.

PREP FOR RE-INSTALLING
Check to make sure all your gasket surfaces are clean and ready. It is your choice to replace the pan with just silicone sealant or use a gasket. The nice thing about this engine is there are no main bearings to go around: the entire oil pan surface is straight and flat.

You’ve probably already removed the oil dip-stick. Now is a good time to cover the dip-stick hole so gunk doesn’t get into it. I also flushed my dip-stick hole, but that’s a personal issue I’m sure many don’t want to hear. One of those spray can caps can be used to cover your own, personal dip-stick hole, just don’t tell your wife. Sticklers-for-detail might want to take this time to paint the dip-stick handle and let it dry. Remember: nobody likes a dirty dip-stick…except my first wife, and unless she’s in your neighborhood, you don’t have to worry about her. Just get a restraining order and you’ll be fine. Mirrors, garlic and crucifix’s can help keep her away, too.

The bottom of the engine block needs to be clean for the new oil pan gasket or the sealer to do any good. While you’re down there, clean the oil sump surface. You don’t want the oil pump sucking any air, so the surfaces and gasket should be installed with care.

The front of the block should be clean, too. If you’re installing a new water pump, now is a good time to do it. Once that’s done, you won’t be getting any gasket shavings into the new oil pump work. Be sure to remove any gasket sealer on the pump plate mounting surface of the engine block.

Using focused care, you can set the gasket onto the oil pump plate back, and the oil filter unit. Note there are very small passages in the oil pump plate, and you DON’T want gasket sealer plugging up those passages. I used enough sealer to hold the gasket in place: more is not better. I smeared it around with my finger to make sure it covered all the surface area necessary, and took care to remove slop-over with a cotton swab. As the oil pump sticks “out”, laying the plate on the work bench, gasket-side down, means the pump needs to hang over the edge of the work bench, but this allows you to squish down on the oil pump plate gasket and assure an even set. Flip it back up and make sure all the holes and passages align, and sealer that oozed out is removed. Set the gasket for the oil filter unit, too.

Your oil pump kit SHOULD HAVE the oil seals already in place. Just for shits-and-giggles, make sure the old seals didn’t remain on the crankshaft or the balance shaft. While you’re inspecting those, wipe them clean with a rag to remove any dirt or first-wife residual particulate. Using either clean motor oil or assembly oil, give those dudes a thoughtful coat of lubricant…just enough, not too much. Give a coat (or sweater, if the weather’s nice) to the inside of the new seals on the oil pump, too. If your gaskets are set up enough, slowly and carefully set the oil pump plate in place. See if it all matches up good, get a feel for how the whole thing sets. Take note of the right-hand side balance shaft, and how it needs to install. It can only go in one way…unless you removed the mirrors and garlic and my first wife is in your garage/carport/living room.

Set the oil pump plate back on your work bench. If necessary, call the cops on my first wife to have her removed.

I’m writing this a week after my own installation, and the Haynes manual is over in my garage. So be sure to follow the instructions in your manual in case I’ve forgotten any important details.

Get your cardboard bolt-holder at the ready, and clean off any really gunky nuts or bolts. Remember that the oil filter unit’s bolts are separate from the oil plate’s bolts, but work in conjunction with them.

Remove the screwdriver from the side of the engine: you’ll want to turn the balance shaft in order for it to engage in the oil pump.

I placed gasket sealer on the gasket surfaces about to mate with the engine surface, with the same care I used for setting the gaskets. It is very important to keep the small oil passages clear of gasket sealer, guys. Poor oil circulation was partly what got me INTO this mess.

Oil leaks in this area of the engine are fatal: you don’t want ANY oil EVER getting on the timing belt or gears. Oil on the gears can allow the belt to slip, and oil on the belt will cause it to deteriorate. Let this be the cleanest phase of your repair, and that means your hands are clean, too. The gasket sealer on both sides of the gasket are the best we can do to keep dirt OUT of this timing chamber, as well as oil IN its passages.

With its gasket in place, install the sump pick-up, using the manual’s torque specifications. The sump can only go in one way.

Place the oil pump plate into position…take your time, don’t force anything…and engage the oil pump/ silent shaft connection. Turn the oil pump shaft to engage the balance shaft’s alignment. When everything is aligned press the plate on, making sure all surfaces are unobstructed and ready for bolts. Be sure to guide the plate over the shafts with new oil seals, and make certain they seat properly.

Get a couple bolts in place, finger-tight, to hold the plate onto the engine block. Put the oil filter unit in its position and get a couple of those bolts on, too. Press the units against the engine block to get a good seal.

Set your belt tensioner in place with its bolts. Include them in the torque process. You will need to loosen those bolts during the timing belt phase, but for now, they are an important part of oil plate installation.

Set the remaining bolts into position, only finger tight. When they’re all in, start with the inner-most bolts, and tighten one-quarter (¼) turn. Work in a clockwise pattern to slowly tighten the outer bolts a quarter turn. Take the time to tighten them all in this way: it will take several ¼ turns, but in doing it this way, you are assuring a good seal against the engine block, and you are avoiding cracking the new oil pump plate.


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Yes, you in the third cylinder: you have a question?

Yes. Wudduh ya mean inner-most clockwork orange ya glad t’ see me?

Here is a Serving Suggestion:
Note this photo is of the pump further along than where we are now. It is only for illustration.

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Torque the bolts to manual specifications. Go have a smoke break.