'90 2.4 oil pump replacement

[camoit]

Do you have hydraulic lash adjusters? Or is it manual adjusters?
If it's like a 2.0 then it's in the front cover. But IDK on the 2.4.

[royster]

Do you have hydraulic lash adjusters?

Yes.

Thanks, camoit. I have the 2.4 and the oil pressure DID come up. I was paniced for a while, though: I know what I SHOULD have seen, but that didn't happen until the engine ran a bit. I had horrible visions of running an engine with no oil flow.

All is well, and I can post a thread about the experi...wait...this thread IS my experience.

I owe a post, here.

Gimme some time to relax and I'll report. Information is also available at the Roy's Garage thread.

[royster]

If you didn't know it already, you can click on the images to enlarge them

The common accepted knowledge for timing-belt-run engines is to replace the timing belt(s) every 60,000 miles…some less than that, but the point is: if you’re replacing the timing belt, you might want to consider replacing the water pump and oil pump while you have the engine stripped down that far. For some, the oil pump replacement is a necessity. For myself, I opted for preventative maintenance.

The first thing you need to do is order the oil pump. I got mine through RockAuto.com and it cost $177.00. This kit came with gaskets, spacers and replacement sprocket with new nut, though I did not use the spacer or sprocket because they were much wider than my 2.4 4G64 wanted.

You also need to order the oil pan gasket, unless you decide to just seal the pan with silicone sealant. I'm old-school, and recommend the gasket.

You also want a fresh tube of silicone gasket sealer.

A few pieces of cardboard will allow you to make a bolt-holder for the various components you’ll remove…this keeps you from putting longer bolts in shorter holes: something quite illegal in at least 47 states. Timing belt cover, oil filter holder, and the oil pump plate are bolt patterns you definitely want to keep straight. I made a holder for the oil pan bolts, but they are all the same length so there might not be a need to keep them in order. However, in any automotive repair, it’s always wise to put the same bolts back into the same hole. Marriage works that way, until the kids move out and the dog dies.

Shown below: cardboard bolt holders for cylinder head project
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Acetone is useful for cleaning the mating surfaces, as personal lubricant only works for HUMAN mating surfaces, not automotive.

You absolutely need to have a Chilton or Haynes service manual, and these run about $20 in any auto parts store. Though you can get the information online, it is good to have reference right there at the work bench.

Of course, you’ll need oil and a new filter to replace that which you’ll drain in order to get the oil pan dropped. You might want to run some Seafoam in the crankcase for a bit before draining the oil to help keep the engine’s interior clean.

A couple cans of brake spray cleaner is good to have on hand. If mechanic’s hand cleaner is on sale for a $1, snag a couple cans of it: you can use it to clean off the oil pan once it’s removed. An old (or disposable) paint brush works well for that task.

All of these items require environmental consideration. If you know anything about the wave of pollution catching up to our society, like the Pacific Garbage Patch, then you know you need to do your part to help keep the planet a little healthier. Cars have been an environmental disaster for us, and the least we can do is minimize that damage with personal responsibility. Yours is not the only vehicle in the world: there are millions of them. Same with the products containers you throw away: the landfills can only hold so much before that crap comes floating back to you some day. The Fukushima tsunami proves it DOES come back at us, and then travels around the world in the natural currents of earth’s water and wind. “Everyone lives downstream”.

As I highly recommend draining and removing the radiator for this project, you want to be aware of the anti-freeze you are responsible for. Dogs and cats will try to drink it, and it WILL kill them. Avoid that heartache and be sure to keep your drained anti-freeze in containers. Thanks to corporate marketing of ridiculously colored children’s beverages, very small children, too, might think the anti-freeze is “Kool Aid”, and since it IS sweet to the taste, you really need to take care with its handling.

If I can instill anything on the reader, it is: to resolve yourself to take adequate time to do a good, clean job, and that involves a little extra preparation you will NOT regret. Particularly since you'll be replacing the timing belt and tensioners, easy access to the front of the engine is worth the time it takes to remove the radiator, and you might consider taking the bumper off, too.

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I don't have that under-bumper skirt on my truck, but if you DO, you'll be fighting it every time you want to get under the engine. You might want to take it off. These are all opportunities to clean and detail parts...maybe paint the bumper, behind the grille and perhaps the radiator tank.

If you're replacing the oil pump, then your truck has lots of grease and oil on it: take the time to clean this off before you start, and you'll keep the job from getting gunked up. HERE is one idea for de-greasing the engine. If weather permits you to use a high-pressure car wash spray, it's a good investment.

NOTE: "Silent Shaft" and "Balance Shaft" mean the same thing. These terms refer to the same part.

[royster]

Again, many opportunities are available: the radiator out means you can turn it upside-down and back-flush it with the garden hose or shower hand-held sprayer. Spray the cooling fins from the engine-side of the radiator, to push out the dirt and bugs from years of trips to the 7~11. When it goes back into your truck, it will now give you better service…all for a few moments of attention.

And before starting out, be sure a good space is cleared for storing the parts you’ll be removing. Removing a part amidst clutter, and trying to find a place to put it results in a frustrating job. If you take the time before you start, you eliminate 90% of the frustration naturally built-in to haphazard mechanical tasks. If your work area is neat from the start, it sets the pace for a successful repair. In my home-improvement work, I always clean up before and after each phase of a project. I do the same for mechanical repairs. It provides clarity, locates missing tools, and gets rid of empty containers that get kicked around. Take out the trash. Eliminate distraction and confusion. Take out used shop rags. You have a 4-hour repair ahead of you that might take days to complete because you can only work on it 20 minutes a day: make your work space accommodating to a job well done. Clean up after each session, or resolve to start the next session with a clean up and tool re-organizing. You’ll have continuity to the task, and you’ll always know where you left off.
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The book may tell you a different approach, but you need to start by disconnecting the battery. This does more than eliminate shorting out stuff when you spill that Keystone beer on the starter motor: it also affects the ECU, which monitors electrical components. Put that nosey bizzy-body to sleep while you’re working by disconnecting the battery. When the job is finished, and the ECU wakes up, it will monitor the system, and adjust things accordingly, without starting rumors and gossip about the affairs that went on the night before.

Where to start from there? It’s all gotta be done, but a good starting point might be removing the fan and water pump pulley, then the crank pulley. The crank pulley has 4 small bolts and the larger center bolt which is 19MM. Designate a ½” drive ratchet with the 19MM socket for turning the crankshaft…you’ll be doing a lot of that. You can counter the loosening of the four smaller bolts by holding the center bolt with your ratchet or box-end wrench. Be sure to put the small bolts in a sandwich bag or a container where you won’t lose them. You don’t want to put them back on the crank pulley since you need to put the pulley on and off several times during the operation, for turning by hand (to see the timing mark).
Next, make a cardboard bolt holder for the timing cover bolts. As there are different lengths that go in specific places, this is an important detail. Draw a couple indicators of where the top is, and where the bolts go…perhaps a crude outline of the two pieces that make up the timing cover. Then remove the timing belt cover.

If you take the time right now to clean off the cover, inside and out, it is ready to go back into place clean. Then store it thoughtfully. I took the additional care to soak it with mineral oil while it’s out, then before re-installing, wiped the mineral oil off. This rejuvenates the plastic.
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Be careful to not lose the gaskets in the cover’s grove, and make sure they’re grease-free: when the timing belt goes back in, you want no oil or grease anywhere near it. Have a stash of clean rags just for those areas crucial to clean operation.

Now it is time to make sure the #1 piston is top-dead-center, and that your timing marks are all aligned. Take the distributor cap off, noting (by the book or the marks you’ve placed on the distributor) where #1 firing position is. It should be just past the bottom cap clip. I marked mine so it’s a no-brainer, and is now second-nature to me. But only because I practiced sure-footed learning.

Use the center bolt to turn the engine to where #1 is at TDC. You can put the bottom timing cover back on, then the crank pulley, but there are timing marks on the timing belt pulleys and oil gear to show you where the timing marks are. Before we go any further, let’s highlight a problem that occurs all the time: the timing mark for the cam gear. It is a little bump on the cylinder head, and NOT THE TOP OF THE HEAD. This distinction is the difference of being off one tooth, and that difference is huge.

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You can mark that little bump with a drop of paint or marking pen. The main thing is to know it's your primary timing mark for the cam.

[royster]

There are clear illustrations in your manual as to where the timing marks are. Don’t worry about the oil gear mark: you’re replacing the pump and will be re-setting it. Once you are sure of the TDC position, remove the timing belt.

A 10MM hex head wrench-bit is needed to loosen the top tensioner bolt. Then loosen the bottom tensioner bolt and let the timing belt relax. Then you can remove the belt, and if it’s in good shape, store it in a safe place where it can remain untwisted and immune to oil spills. That means the Gulf Of Mexico is out of the question.

You’re going to have to remove that crankshaft center bolt...the pulley comes off first by removing the four small bolts. The crankshaft bolt holds on the timing gears, and while the book says you need a “helper” to assist you, I managed to do this by myself. It involves taking the inspection cover off the bottom of the transmission. (Be mindful of the nuts and bolts and where you place them). My trans is a 5-speed, but the automatic has the same basics: a flywheel with teeth for the starter. You’ll need to put a screwdriver on the right-hand side of the bottom of the bell housing, in one of those teeth, to keep the engine from turning while you loosen the crankshaft pulley bolt. Do not use the starter motor hole for this task. With the 19MM socket and ½” drive handle set to remove the bolt (counter-clockwise) you’ll do well to put a 24” or so piece of pipe on the ratchet handle…some call it a “cheater bar”, others call it “leverage pipe”. If it’s behind your front seat, it’s a “defense mechanism”.

You can hold the screwdriver in place, on the surface of the bell housing while engaged in the flywheel gear-tooth, and pull (or push) the ratchet with your other hand. Using your leg is fair game. It shouldn’t take much to get the bolt loose, and from there you can just ratchet it off.

A wheel puller removes the timing gears fairly easily once the center bolt is off. Now you can see the work before you.

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NOTE! Engine shown is a 2.0

The timing gears and balance shaft pulley need to come off. The left-side balance shaft gear is held on by a nut that needs to come off...my manual doesn't give any definitive means by which to do this.

EDIT - Redneckmoparman suggests the following:
"I would HIGHLY reccomend losening the bolt with the belt installed and the crankshaft held still. Once it is loose you can loosen the belt and remove it. With the belt off the gear should come off easily, and then the spacer behind it, slid on the balance shaft, should come off. I DID NOT DO THIS UNTIL I WAS REMOVING THE ASSEMBLY AND IT WAS TRYING TO BRING THE BALANCE SHAFT OUT WITH IT so please, make sure its just the small part left before you remove the front cover."

I ended up putting a rag over it and holding it with channel locks while loosening the nut. I later thought that, since the oil pan is off, the balance shaft can be reached from under the engine and stopped that way. That is how I tightened the nut upon re-installation, but take care not to damage the shafts in any way as they CAN get bent or out of balance.

Forum experts might wish to add their own trick for this glitch in detail. Perhaps a quick jolt counter-clockwise works if the belt is still tensioned. I dunnoh. No one said anything about it, or I missed that part of the movie.

The nut and bolt for the tensioner come off, too.

[royster]

The reason you have to drop the oil pan is because the oil sump pick-up is bolted onto the oil pump in there.

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Drain the oil, and while it drains, you can make use of the time by wiping off the grease from around the 5,742 oil pan bolts you’ll need to remove. If you didn’t de-grease the engine compartment, you might want to take this time to at least wipe off the cross-member frame under the engine, because you’ll be reaching through there a lot. It’s that, or keep washing your hands and forearms from all the grease you keep getting into. Your choice.

I did not have to raise the engine to get the oil pan out, though the book says you might need to do so. The oil pan is bolted into the oil pump plate, so it has to be unbolted before you start unbolting the oil pump plate…at least, this is a sure-footed approach. It’s all gotta be done.

Once your oil is drained, remove the oil pan bolts and save them in a plastic bag or container. As I mentioned earlier, I made a cardboard holder for them, only to find they’re all the same length. I could be wrong about that so pay attention as you remove them. Dropping them all into a tin can with cleaning solution makes for a clean re-assembly, then let them dry, then bag ’em.

Use a wooden block to tap the sides and front of the pan with a hammer (don’t beat on the pan directly with the hammer). This helps loosen the oil pan gasket or sealer. You don’t want to pry the oil pan lip, because if this action bends the lip, you’ll get a serious oil leak there. To keep the oil pan mating surface true, try your best to knock the pan off its mounted position with tapping it. If that doesn’t work, a very thin putty knife can be carefully used to wedge around the lip of the pan. Beyond that, you might consider explosives.

Once the pan is off, it can be cleaned and stored. Clean the mating surfaces real good with acetone. When dried, I applied the silicone sealer and set the gasket. I got the gasket in place with the sealer on the pan, then flipped it upside down and put it on the workbench surface, applying pressure to assure an even seating of the gasket. Then, flipped back up, I insured each and every hole lined up. I set it aside to allow the silicone to set. The gasket didn’t slip or fall off as I re-installed the pan, and as MY job is now completed, I can assure you I have no oil pan leaks. So this approach should work for you.

Remove the two bolts holding the oil sump and remove the sump. Yuck! Whatta mess! Get that thing cleaned up, back-flush it and spray it with brake parts cleaner (unless you opt to install a new one). I found a couple boogers inside the screen, and worked to get them out. Remember: this sump is all there is to keep particles and dropped bolts from entering the oil pump. Oil doesn’t get to the filter ‘til after it goes through this sump. Make sure it’s clean, and that includes the mounting surface, which likely has gasket material on it.

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It’s time for another cardboard bolt holder, and this one is for your oil pump plate bolts. Since, in theory, you HAVE the new pump there, you can actually just trace the bolt holes right from the pump itself, onto the cardboard. Poke the holes with a poinky object and enlarge them with needle-nose pliers. You want them about ¼” wide. Make a seperate area on the cardboard...lower left-hand side...for the five bolts that come off the oil filter unit. Designate a separate hole…sort of like a mistress…for a single bolt (it couldn’t find a date) off to one side. We’re about to discuss this mystery bolt and the reason for its being.

Here comes another crucial point that is missing from my manual: the nut that holds the mysterious Silent Shaft. And the conspiring bolt that protects the Cave of Ali Bubba…he’s the redneck version of the Arabic story. Facing the engine, there is a bolt on the right-hand side, back there near the starter. This bolt is how you access the Silent Shaft secret society.
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Remove the bolt, and try to get a phillips screwdriver into that hole. Dinner and drinks might work, with a few personal complements thrown in, but since the timing belt is off, it’s perfectly okay to turn the oil pump gear and get that shaft to turn. Get a feel for it: regardless of your heterosexual inclinations, you’ll be handling The Shaft a bit more during this operation. It’s okay: everybody does it, but no one talks about it. That's one reason it’s CALLED a Silent Shaft, based on secret society principles.

Place that bolt in the cardboard holder in that designated single spot.

Turn the shaft until the screwdriver goes all the way in, and when you turn the oil pump gear back and forth, you can feel it bump against the screwdriver. Leave the screwdriver in there, for now.

Camoit provides us this great photo, of a crucial step: removing the vault door to the Silent Shaft Treasury. Actually, it's an access panel to the nut that holds the balance shaft in place. I used a nail-set and hammer to tap it counter-clockwise in order to remove it. Camoit suggests a center punch. At any rate, it comes off so you can remove the nut hiding behind it.
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Note the plate has an "o" ring, and the replacement ring SHOULD be in your oil pump kit. Play it safe and retain the old ring, for now.

You left the screwdriver holding the silent shaft because that's how you're going to get that nut loose: holding the shaft in place as you turn the nut counter-clockwise. Your kit may or may not have a replacement nut...next election is 2016...but save it just the same. Instead of a hole on your cardboard holder, use a screw through the nut to attach it to the cardboard...maybe near the lonely Silent Shaft bolt that can't get a date. Also be very sure to keep that cover in a place it won't get lost. As an oil seal, it's a small but crucial component. Perhaps in a sandwich bag, taped to the cardboard bolt holder.

Removing the oil pump plate bolts:
As you’ll notice with so many of the manual’s instructions regarding component removal, starting from the outside, working toward the center seems to be the theme. The reason for this is the more pliable aluminum parts against the iron block tend to have a slight curve to them. The aluminum has some “give” to it, and assuring you’re not stressing the part allows this ’give” to not become “break” or “crack”. ¼” turns are recommended for each bolt, one at a time, several times, until the bolts are finger-loose, then you take them all off, placing them in their cardboard holding cells. This isn’t so important on a part you no longer intend to use, but it IS important when you go to install the new part, which will be a reversal of this procedure. You will install the bolts starting from the center, working your way outward.

Nit-picky details -
... did you disconnect the oil pressure sending wire? It's near the oil filter. It gets lots of oil and grease, so spray it clean with some electrical parts spray or brake cleaner spray so oil doesn't short it out. Inspect the wire for breaks and electrician's-tape it up if you need to.

... was your oil guage/light working? If not, get a replacement sending unit.

...if you haven't done so, remove the oil filter.

[royster]

Something the manual says to do next, I had no idea why, nor do I have any concept now, but I will share with you what the manual says, and what I did.

It instructs you to open the pressure relief valve and take out the plunger and piston. “Take out” could mean dinner and a movie…we WERE trying to get that screwdriver in the hole. The problem I had at this point in the operation is that I couldn’t locate my 22MM wrench, and even if I had it, there wasn’t space enough to get the box end over the bolt.
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I ended up taking the unit apart after removing it. I cleaned it out real good, and put some assembly oil in things, then reassembled it. The manual’s instructions for re-installation seemed rather casual, so I don’t think this is a crucial step, but it is good to get this component clean, since you’re not replacing it.
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You see the oil filter unit to the left: it is the first to come off, and the last to go on. It is part of the overall bolt pressure against the oil pump plate, so it will be torqued in sequence as the new pump goes on.

But let’s get the old pump off, first.

If you loosened the bolts and placed them on the cardboard holder, then you’re ready to remove the oil filter unit, then the oil pump plate. Tapping with the block will help loosen it, a nudge here and there will get it to come off, but keep in mind there are two oil seals and a balance shaft fighting you a little bit. Keep an eye on the balance shaft end, and make sure it doesn’t come out attached to the oil pump, itself.

At this point, conduct a real good clean up, get the old gasket material off the front of the block, and clean it real good with acetone. If you haven’t done so yet, get under there and clean off the oil pan surface of the block. You’re now at the halfway mark of your journey.
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Almost everything you removed can only be put back one way, so you need not panic about which side of this or that goes where. Take note of the two crankshaft gears, and note the "photographic" impression the gears have left on each other. Note also the flanges between them, as it's important to put these back correctly. The 'photographic' impressions are a big help in re-installing them right. Observe that the timing marks are clear on each part.

It is VERY important to have these parts as clean as possible, as they conduct the timing of the whole engine by way of a rubber belt...a belt that does not want oil or grease on it.

You'll find that if you open the old oil pump, even those gears are marked with timing marks. Note that the balance shaft end can only be put in one way: this all helps eliminate guesswork and mal-placing the pieces. It is the oil pump that turns the balance shaft.

An important note I pass along is that the new oil pump didn't seem to turn clockwise: it bound up, but WOULD turn counter-clockwise. This caused me to panic, but later I found that when the balance shaft is in place, proper orientation takes place. Remember to never turn the engine counterclockwise more than a scoash, a kunt.hair or a tad. This is more important once timing belts are on, but I took caution in not forcing the new pump to turn clockwise.

It all comes out in the wash.