Oil Pump - Replace working unit with high-flow?

[natenkiki2004]

Sometime in the near future, my engine's coming out due to a severe oil leak, either from the rear main or oil pan. Gonna do them both.

I've been contemplating doing the oil pump while I'm in there, just for good measure. Before getting into that though, I finally got an oil pressure gauge on today. When cold at idle, it's about 60PSI. When it's warm, cruising on the highway between 2,000-2,500RPM it can be around 45-50. When idling in gear at a stop, I saw it dip down at low as 20 but usually 25.

I'm pleased with these readings considering the history of the vehicle (neglect, thefts, etc) and being almost 227,000 miles. I would be happy just sealing the pan up but jd4242 is always talking about the Mellings M-328 high flow pump. Specifically, in this post here:
http://www.explorerforum.com/forums/showpost.php?p=2224198&postcount=7

I could stretch funds and replace my pump with the high volume one. My question is, would it be worth it? I have plenty of other things to spend the $$ on that need doing on the Explorer (rocker arms & pushrods are next...). But, I want this vehicle to last.

Thoughts?

 

[Anime]

The engine in that vehicle is heavily modified, and probably benefits from a high volume oil pump.

Stock engines, or those with just mild modifications, do not require a high volume oil pump, and using one can actually be worse than a stock pump.

That said, the unit for the 4.0L OHV V6 might not be that drastic of a change, so it could work, but then again, why pay a high price for something the engine doesn't need that won't give any real-world benefit?

I'd stick with a stock oil pump unless you are rebuilding the engine with ported heads, a 422 cam, etc. etc.

You may not even need to replace it. While it can be a good idea to replace an oil pump with high mileage while the engine is out and the oil pan is off, stock pumps can go pretty long without issue as long as the oil is changed regularly and the proper viscosity (5W-30) is used.

As for the leaks, it's pretty common for the rear main and the oil pan gasket to leak. Just replacing the rear main won't do it though, you'll need to either use a shim ring or the special PTFE rubber seal to get it to stop leaking.

http://www.explorerforum.com/forums/showthread.php?t=298508

Probably a good time to do the front crank seal with the engine out, if you feel like pulling the harmonic balancer. With the engine out, I'd suggest putting in a new timing kit as well, since access will be easy.

 

[natenkiki2004]

That's what I was wondering maybe too much oil pressure in a stock engine is a bad thing? Quite a few of the stock Motorcraft parts are pretty good, almost bulletproof and I'd wonder if by replacing it with an aftermarket one would be a worse thing than leaving it as-is. The problem is, there isn't enough feedback for the Mellings pump to figure out if it's REALLY worth the $150 plus pickup tube.

For the rear main, I already have a seal, SKF 23823 with the shim ring. I didn't like how the teflon seals looked, you can't use them with a ring/spacer and they don't rely on spring pressure to stay tight like a normal seal. I also got a SKF torque converter seal. I've thought of doing the front seal but looking at the engine, I think my problem is just the oil pan gasket, probably leaking down the midplate into the bell housing where it drips out of. There's plenty of drops forming at the top of the pan in the rear, clinging to the bolt heads.

I hadn't thought about the timing gears though. Looking around online, people are saying it doesn't need to be done on the OHV. Maniak on here said his looked perfectly fine at 355k miles. My Explorer was neglected part of it's life but it's going to take me a long time to put on 125k miles to match Maniak.

Would it be super horrible to wait on the timing kit and front seal? From the few pictures I just saw, can't they be done from the front without removing the engine? I'm going to be removing the condenser and accumulator in this go-around so in the future if I needed to, just pop the radiator, fan and grill out and I'd have pretty good access right? I do hate to skimp on parts and I do want this engine/vehicle to last quite a while but this whole engine removal thing is going to have time limits on it as it's going to be parked at someone else's place.

 

[Anime]

A high volume oil pump doesn't affect the pressure much - or if it does, there will possibly be other issues with seals and leaks. High volume oil pumps are just made for performance engines that see high-RPM use. High volume just means they can push more oil, and do it fast so that the engine is never starved for oil when it's going that fast. Thing is, simply throwing on a high-volume pump doesn't do anything for an engine that never sees high-RPM use. The 4.0L OHV is a low-RPM motor, making max torque around 2500 RPM. Sure, you can drive it and rev it to 4000-5000 RPM, but it doesn't DO anything but waste gas.

I would say that the stock Motorcraft pump is higher quality than a LOT of the aftermarket products. Same goes for the water pumps and a lot of other OEM parts for the V6. The Made-in-Germany Motorcraft parts are about the best you can get for this motor, and I personally would only replace the oil pump with another Motorcraft, unless that just wasn't an option at any price. Melling pumps have their place in the world of performance V8s (although there are plenty of people who noticed when their product offerings changed and the quality went way down), but sticking one on a OHV V6 just because, seems like a waste of money for something that isn't needed, but may also very well be a waste of money for something that is lower quality and may turn out to be less reliable than the currently installed part. That would be pretty rough to pay that much for a part and then have a problem.

The timing chain doesn't need to be replaced as often as a motor that uses a timing belt, but at 200,000+ miles, the chain is stretched, and a new chain, with new gears and a new tensioner, will give new life to an old motor and just make the timing that much more precise. I'd say it'd be worth the cost of a Cloyes kit, but you can always wait until it's making noise. Just something that's way easier to do with the engine out.

My experience is that the rocker arm replacement and the timing kit replacement are two of the best bang-for-the-buck items you can do on the 4.0L OHV with high mileage, that both improve performance/efficiency (by restoring the original performance of the engine to pre-worn rocker and pre-stretched-timing-chain levels), and take care of the two items that cause noise.

It would be a shame to waste the opportunity to replace these items easily and painlessly with the engine removed, and then have to do it later with the engine in the vehicle. Yes, it is possible to do, but it is 10-25 times more work, and you will probably look back with disgust that you didn't do it when it would have just taken an hour or two, instead of wasting hours upon hours gaining access, tearing into the engine, and having to work around everything trying to do a decent job.

 

[natenkiki2004]

Thank you for your time in putting out a well-thought post. I agree with your points on the oil pump, I'll leave it.

I completely agree with doing the timing kit at the same time, coolant is drained and it's not that much further to dig for the timing chain. Looking at pictures now, that timing cover gasket could be the source for my slow coolant weep on the driver's side.

It's very tempting to do the timing kit but time and budget may not allow it. I'm a novice and pulling the engine is going to be a big ordeal, something I never thought I'd do. It adds $110 to the cost I already have for parts. I know it would be a good thing to do but I will think about it more.

Again, thanks for your help.

 

[Anime]

It's very tempting to do the timing kit but time and budget may not allow it. I'm a novice and pulling the engine is going to be a big ordeal, something I never thought I'd do. It adds $110 to the cost I already have for parts. I know it would be a good thing to do but I will think about it more.

$110? Rockauto sells the 5-pc. Cloyes timing kit (Made in USA) for $67 plus shipping, and you can use the 5% off coupon to shave a few bucks off.

http://www.rockauto.com/catalog/x,carcode,1119608,parttype,5756,a,Ad+Code+www.google.com+

Ford no longer sells the timing kits for the 91-94, just the chain and cam gear, since they are the same ones used in the later 95+ models.

 

[Roadrunner777]

I have done two timing gear changes with the engine in, and two with the engine out as part of rebuilding. Let me put it this way:

I remember every torturous moment of both engine-in jobs, they were multi-day deals and one ended up going to the shop anyway because I could not get the timing cover to go back on. (That was a 70's era Toyota).

By contrast, the times with the engine out were... how shall I say... '6 beverage' jobs.

 

[natenkiki2004]

$110? Rockauto sells the 5-pc. Cloyes timing kit (Made in USA) for $67 plus shipping, and you can use the 5% off coupon to shave a few bucks off.

http://www.rockauto.com/catalog/x,carcode,1119608,parttype,5756,a,Ad+Code+www.google.com+

Ford no longer sells the timing kits for the 91-94, just the chain and cam gear, since they are the same ones used in the later 95+ models.

Gotta add the front seal and gasket kit for the water pump and timing cover though. Gotta do it right

I have done two timing gear changes with the engine in, and two with the engine out as part of rebuilding. Let me put it this way:

I remember every torturous moment of both engine-in jobs, they were multi-day deals and one ended up going to the shop anyway because I could not get the timing cover to go back on. (That was a 70's era Toyota).

By contrast, the times with the engine out were... how shall I say... '6 beverage' jobs.

I totally agree with you guys. Budget isn't a terrible concern, I can do the timing kit, I could also do the connecting rod bearings and main bearings if needed too. The big deal here is time since I'm going to be on someone else's watch. I've never done any of what I have ahead of me. I have no experience. The quicker I can get done (without cutting corners and rushing the job), the better. Adding things that don't NEED to be done may cause headaches and delays which I would normally be ok with but like I said, it's not my watch.

 

[Anime]

If you do get the timing parts, I'd suggest getting the green timing cover gasket from Ford, it seems to be green because of whatever material it is made of, that doesn't stick to the parts and so crud doesn't get into the oil pan with the timing cover off when pulling the gasket. A standard gasket will work, but will need to be scraped off the next time it's done.

You don't NEED to pull the engine either, rear main and oil pan gasket leaks are pretty common and lots of people just live with it.

If you're going to the trouble of pulling the engine to address these minor issues, you may as well invest in fixing the other stuff that is much easier with the engine out, unless you want to make it harder on yourself and do it later with the engine in, or pull the engine a second time.

 

[natenkiki2004]

I did live with the oil leaks for about a year, they were acceptable. But something gave and I was leaving large puddles everywhere. It's dripping onto my exhaust, causing a nice burning smell. Even with Bars Rear Main Seal Stop Leak in it, I've lost 1/4" on my dipstick after less than 150 miles. I drive this Ex for business work and it's embarrassing to leave puddles at people's homes, downright rude to them as well.

I know the rear main can be done by dropping the trans but you have to mess with the transfer case and drive lines. Not a huge deal but that's just for the rear main which may not even be my problem as it's already been replaced by the previous owner. To do the oil pan, you have to drop the front axles and lift the engine, even then it's a tight space and you have to work under the car. Bottom line is, I have to unbolt the trans anyway, it seems like it would be easier to lift the engine out to take care of both seals and be done. Having the engine out, I can inspect the bottom end for any extra wear and take care of bearings at that time.

Like I said, I agree with doing the timing kit, I just don't know what kind of timeframe I'll have. If it was my garage (I don't even have a garage or cement pad or asphalt road to work on), I'd have the kit ordered, no question. The more I dig into, the more time it will take.

*EDIT*
Just bought the OEM timing cover gasket. I WILL do the kit, it's just a matter of when. I also remembered that I'm going to be doing the frost/soft plugs on the engine. I don't want to have to pull it again to do something so minor and simple.

 

[Anime]

Dropping the transfer case/transmission to get to the rear main takes a bit of work, but is doable with jackstands/ramps or just stacking wood 2x10's to lift the wheels, unlike pulling the engine.

You should inspect the bottom end, but usually if there's a problem, you have to disassemble the engine, connecting rod bearings and bottom end parts aren't something that should just be replaced individually, or just by popping them off and new ones back on.

I don't see the timing replacement being anything more than pulling the timing cover and swapping out the parts, then putting the cover back on, which should be even easier since you'll be pulling the pan anyway. The most critical part is putting the No. 1 cyl at TDC so the timing marks line up and putting the new timing gears in the same position when replacing them. That and not pulling off the retainer for the tensioner before it's mounted in position.

Good excuse to do it if you've got coolant and oil leaks in that area.

 

[natenkiki2004]

That's twice this site has eaten my post...

Anime, I'm looking at getting a front parts list together. I already have the green timing cover gasket but I need to get the rest of my list figured out. What I know:

- Water pump gasket
- Cloyes timing chain & tensioners

What I don't know is how many oil seals there are. I see both a front crankshaft seal and timing cover seal. They're both the lip-type oil seals but they are two totally different sizes, not width but diameter. Do I need both or just 1? Also, there seems to be extra tidbits in the "timing cover gasket set" which I don't really want to buy since I already have the cover gasket, I just need the water pump gasket. Are the other smaller gaskets necessary? I can't think of where they might go.

FYI, I'm looking at RockAuto for these parts.

 

[Anime]

There's one seal for the crankshaft and one for the camshaft, Rockauto mixes terms so the "timing cover seal" is what they call the crankshaft seal on the timing chain cover. If there's not an image of the part or you're not sure what it is, you can put the part number into google or search on ebay and find out what the part number is actually for.

Like you said, you don't need the timing cover gasket set, but they might be a good way to get the parts other than the timing cover gasket, since they come with a timing cover gasket, water pump gasket, the camshaft seal, and the tiny triangle gasket is for the tensioner.

Sometimes the Cloyes kits just have a loose tensioner and no gasket for it in the kit, or the gasket is loose and gets beat up by the timing chain and gears, but you can either just leave the stock tensioner gasket on if it stays in one piece or maybe call Cloyes and ask them to send you out a few depending on what you wind up with. There doesn't seem to be any listing on Rockauto for the tensioner gasket by itself.

You don't really need the crankshaft seal unless there is a leak, which you can tell by there being gunk or an oil film down the front of the oil pan under the harmonic balancer, but if you do the rear main seal you might as well do the front crank seal too, especially with the engine out, as pulling the harmonic balancer to replace that seal and try to pound a shim on the crank with the engine in will be quite a hassle.

You can actually get a sleeve kit for the front crank just like you have for the rear main, though I can't say for sure how well they work with a regular SKF seal, that's something you'll have to find out. I have heard that the PTFE rubber seals work well without having to use a shim, and some have had success with the Viton seals as well.

Rockauto actually has a Fel-Pro timing cover gasket kit that comes with a sleeve and it's under $12, either that or you could get the Victor Reinz kit on closeout for $5 if you're buying other stuff on closeout to make the shipping worth it.

 

[jd4242]

Some of this info is true for regular motors but not the 4.0 ohv when it comes to oil pump and flow..the ohv is a POORLY designed motor when it comes to oiling..as you have seen on your gauge oil psi drops drastically at idle when warm and honestly is pretty low all around when compared to other motors..

the oiling of the valve train is HORRIBLE. .this is why lifters get clogged, pushrods wear, rockers wear, valve tips and even down to the valve guides. .you can replace them all with better aftermarket parts to extend the life but boils down to they dont get enough oil..the m328 just keeps you basically in the ""good" range for psi but the flow to upper end is where the benefits come into play..I highly suggest it, mellings pump is OE for ford and you can reuse the pick up tube, just make sure its EXTREMELY clean..

Timing chains, gears and guides should be replaced especially if its a 90-96..the guides wear, chain stretches and the worse flaw is the small key on the lower gear.in 97 the changed the key length but you cant use that unless you order a 97 crank from rock auto and 97 gear set..if you plan to do crank bearings then this is the way to go as the crank is turned and balance with bearings. .

 

[natenkiki2004]

Dumb question for you Anime; where's the camshaft seal and why is it needed? From what I've seen, obviously the camshaft doesn't extend out through the timing cover like the crankshaft does. Is it behind the sprocket on the camshaft? If so, why is there a seal there, I'd imagine you'd want oil all up in there, not sealed in/out. Unless it's got something to do with passages and flow?

I think I'll go ahead and do a front crankshaft seal. It's gunked all over on the bottom half. No wet areas up front but it's caked up to the point where all you see in the front is the tone ring on the harmonic balancer and part of the crankshaft sensor. I probably don't need to replace it but just like the timing chain, it's preventative maintenance to help keep this beast living trouble-free. I get 1 shot at this and need to do it right.


jd4242, I agree with your points but I'm really wondering if replacing the oil pump is a good thing to do in my situation. I don't have the funds for a new one and I'd wonder about the longevity of the mellings. From the research I've done, I'm quite pleased with my oil pressure, considering the history of the engine. Even fully warmed up, sitting at idle in gear at a stop light, it doesn't dip below 20. When cold, it's up around 55-60 or so, activating a bypass from what I've read. Cruising around, it's 30-40, depending upon RPM obviously. With 225,000 miles on it, having had a rough life, being stolen twice, driven hard and lack of oil changes... I'm pleased with that. I'm not going to be piling on the miles and I'll be treating this rig right, if I can get 100,000 miles on this next set of pushrods & rocker arms, I'd be quite pleased.

 

[Anime]

The seal is for where the camshaft exits the block into the timing cover - the camshaft has to go out from the block, otherwise there'd be nothing for the other timing gear to attach to. That's what the timing chain does - it links the camshaft to the crankshaft via the gears and the chain. The seals just keep the oil in the engine rather than allowing it to pour all over the place inside the timing cover. Some oil does still get up into the timing cover from the pan on the bottom (hence the timing cover seal for the crankshaft) but it's just to oil the chain. The idea is not to have excess oil for objects in motion to have to wade through - a crankshaft having to slash through an oil pan full of oil is enough of a drag on a motor.

The oil pump is a roll of the dice, no telling when it will go, if ever. Oil pump failures don't seem to be very common on the 4.0L OHV. If any members that did have one fail posted the mileage that it happened, we could get an idea of the mileage range and plan to replace it before that.

 

[natenkiki2004]

There's one seal for the crankshaft and one for the camshaft, Rockauto mixes terms so the "timing cover seal" is what they call the camshaft seal.

After doing some more research, I'm even more confused. I went to fordparts.com and looked up crankshaft front oil seal and it came back as Ford part number 6700. Looking at Rock Auto, both the "timing cover seal" and "front crankshaft seal" are meant to replace the Ford 6700 part number. They're both very close in size.

I then checked fordparts.com for a camshaft seal and they didn't list one. Does it really exist? Why would there be a camshaft seal included in a "timing cover seal" when the only seal in the timing cover is for the front crankshaft?

Just for reference, I'm looking at the SKF 16473 which is listed on Rock Auto as the "timing cover seal". As well as the Timken 2012V which is listed as "crankshaft seal, front".

I was planning to buy parts this morning but noticed this and I'd hate to end up wasting 10 bucks on a seal that I've already bought. It looks like the one in the FelPro "timing cover gasket set" is for the front crankshaft.

 

[Anime]

After doing some more research, I'm even more confused. I went to fordparts.com and looked up crankshaft front oil seal and it came back as Ford part number 6700. Looking at Rock Auto, both the "timing cover seal" and "front crankshaft seal" are meant to replace the Ford 6700 part number. They're both very close in size.

I then checked fordparts.com for a camshaft seal and they didn't list one. Does it really exist? Why would there be a camshaft seal included in a "timing cover seal" when the only seal in the timing cover is for the front crankshaft?

Just for reference, I'm looking at the SKF 16473 which is listed on Rock Auto as the "timing cover seal". As well as the Timken 2012V which is listed as "crankshaft seal, front".

I was planning to buy parts this morning but noticed this and I'd hate to end up wasting 10 bucks on a seal that I've already bought. It looks like the one in the FelPro "timing cover gasket set" is for the front crankshaft.

I mistakenly use the word "camshaft" instead of "crankshaft" in that (now corrected) post, the only seal in the timing cover is for the crankshaft, that goes through the timing cover and what the harmonic balancer attaches to.

It still can be good to replace the camshaft seal while you're in there, especially if it's leaking.

 

[natenkiki2004]

So, there still is a seal under the sprocket for the camshaft? I don't see any mention of it anywhere. How would I know if it's leaking if it's well under the timing cover and just 'leaking' into the oil pan?

 

[Benjam]

I don't know of any cam seal on the 4.0 OHV aside from the frost plug in the rear of the block..

Benjam