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Water Pump Failure Prevention

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Yes, the yellow/gold coolant is the one to replace. You can put in the Specialty Green instead, or a universal product like the Peak.

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If your considering changing your own coolant, here's Fords procedure for changing from gold to dark green. It also talks about which parts to replace if 2008 or before.

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2009 MKX Cooling System Corrosion.pdf

Edited by enigma-2
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Nobody responded to my electric pump question and since I found nothing it's understandable. I did speak with Meziere and although they don't make a 3.5 specific kit their WP336S pump connected to the bottom hose is used to replace the mechanical pump. The mechanical pump is sealed with the impeller removed to act as a plumbing joint. They would not recommend one way or the other on how to deal with the timing chain. Considering the amount of information available about catastrophic engine failures due to pump failure this could be the most reliable solution.

 

About the waterless coolant Ford Performance was non-committal. What was once, "We don't recommend any deviation from published information," to "No comment," is a change though. I assume the change is the result of even the NHRA now approving the use of waterless coolant. The entire problem with Ford and other coolants is with the water involved. The silicates and nitrites are added to deal with the problems created by the water. Waterless coolant has an extended operating range and without the water the pressure involved is greatly reduced. The biggest problem with using it is getting all the water out of the system before putting it in. Every bit of it has to come out.

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If your considering changing your own coolant, here's Fords procedure for changing from gold to dark green. It also talks about which parts to replace if 2008 or before.

.

Nothing like a 91 step, 26 page document on how to change coolant.

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Nobody responded to my electric pump question and since I found nothing it's understandable. I did speak with Meziere and although they don't make a 3.5 specific kit their WP336S pump connected to the bottom hose is used to replace the mechanical pump. The mechanical pump is sealed with the impeller removed to act as a plumbing joint. They would not recommend one way or the other on how to deal with the timing chain. Considering the amount of information available about catastrophic engine failures due to pump failure this could be the most reliable solution.

 

About the waterless coolant Ford Performance was non-committal. What was once, "We don't recommend any deviation from published information," to "No comment," is a change though. I assume the change is the result of even the NHRA now approving the use of waterless coolant. The entire problem with Ford and other coolants is with the water involved. The silicates and nitrites are added to deal with the problems created by the water. Waterless coolant has an extended operating range and without the water the pressure involved is greatly reduced. The biggest problem with using it is getting all the water out of the system before putting it in. Every bit of it has to come out.

 

 

They have a rinse, so you can drain it all out including the block drains, then run the rinse, drain it all again and re-fill with the good stuff.

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Yes sir although easier said then done with some engines and I'm not familiar enough with this engine to know one way or the other. With a Coyote it's easier to do if an MMR head cooling kit has been installed to deal with the dead end pocket around the #8 cylinder.

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They have a rinse, so you can drain it all out including the block drains, then run the rinse, drain it all again and re-fill with the good stuff.

On some MY you have to replace parts. More than a simple rinse is the important thing to take away.

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Anybody ever used any of those cooling system flushes like Royal Purple Royal Flush? Drain the coolant, then use a 12oz bottle of the flush mixed with distilled water and bring the engine to temp. Then cool and drain the engine again then refill with coolant. Wonder if they would do any good to completely flush out old coolant, or is a simple flush with distilled water adequate.

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If your changing coolants, completely flush the system with a good flush and lots of distilled water. Mixing coolants can create crystals that can clog.

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I would be replacing green with green. I was just wondering if using a flush product would be cost effective.

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enigma-2,

 

I think the part you are referring to is the thermostat housing.

 

chefduane,

 

Just my 2 cents but I think a coolant system flush with a dedicated flush product is a good idea regardless of changing coolant type or not. They have additives to help break up the "gunk" that builds up in the system that water alone can't do. If you've never flushed a coolant system you might be surprised by how much junk comes out.

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enigma-2,

 

I think the part you are referring to is the thermostat housing.

It's the water pump inlet tube. It's painted on the inside. On cars built BEFORE 4/1/08, the flushing chemicals will remove the paint and contaminate the water pump and cooling system.

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This morning I met and spent some time talking to an engineer that works for a place that diagnoses automotive pattern failures so I asked him what he knew about the failures with the Ford internal water pump. When I first learned about this problem here my thought was that running a water pump with a gear is a bad idea for torque reasons. Apparently that's possible but not the primary cause. The problem is usually the result of the timing chain tensioner. Obviously the tensioner monitors the chain tension as it loosens due to stretch caused by age and wear of the chain, guides and gears. It's also effected by the wear of the valve train in the heads. The water pump is apparently better off to run with the wear from age and use than to be subjected to constant readjusted tensioning of the chain.

 

Some additional information from him was that problems can arise from partial component repairs. He said it's not good to swap out something like a single tensioner that's going bad or just the chain or guides. Get the kit and replace everything if you're going to replace anything. He said a lot of repair shops will replace single components instead of the entire system. He said it was common at one time that because of noise just the guides would be replaced.

 

Finally he warned about using caution with changing oil weights because of oil pressure losses due to age and wear. The hydraulic tensioners operate on oil pressure but are not designed to operate properly with a heavier oil. To a point it can result in to much tension but there is also a point where too heavy of an oil actually impedes tensioning. The oil doesn't flow properly and it also doesn't properly thin with heat along with operating temperatures of the rest of the engine.

 

Thought I'd pass this along.

Edited by I'manedgeowner
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Heh! Sounds like the exact same analysis of the Gen II 4.0L SOHC Explorer. Years '98-'01. Timing chain slap due to the plastic tensioners breaking up and no longer keeping the chain tight against the cam gear. My '98 was in great shape when I sold it other than a bad chain slap. They could grenade at any point or the chain could skip and it's bent valve time. You could wait till she blew and drop a Jasper engine in it (or a JY engine) or tear it down and do a complete timing assembly rebuild. Either way your looking at mucho $$$$.

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Obviously the tensioner monitors the chain tension as it loosens due to stretch caused by age and wear of the chain, guides and gears. It's also effected by the wear of the valve train in the heads. The water pump is apparently better off to run with the wear from age and use than to be subjected to constant readjusted tensioning of the chain.

Loved your write up, but I don't understand your friends reasoning on the tensioner's job. his. In my way of understanding, it would fail faster if the tensioner wasn't there. But it's an interesting proposition.

 

It's my belief that it's lack of maintenance that's the cause. Not changing coolant is very important. Old coolant loses its ability to prevent corrosion and be able to keep the seals expanded. It's seal failure that allows coolant to leak into the bearing and destroy the ability of the oil to lubericate the bearing. Once the bearing wears from lack of lubrication, the destroys the seal between the water pump and engine. One of the main reasons I believe this is, is that most water pumps on these engines do NOT fail. But I'm certain that the chain is well streached by, say, 150,000 miles. So, in my thinking, chain streach is normal, but not the primary cause of failure. Just my $.02.

 

About a year ago, Mactfordedge did a pair of videos on the water pump. What I took away from that was the seal failure precipitated the failure.

https://youtu.be/GddVuKViof8

https://youtu.be/yrmH4S2_ZOI

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enigma-2,

 

Interesting videos but #1 being just watching a water jet, well?

 

First, it's been a long time since my chemistry but I have a hard time with the "acids" in coolant having much of an effect. It takes some uncommon acids to have a catastrophic effect on glass, rubber or plastics. I doubt the seal is made from a rubber that would be effected or that a coolant uses an acid that would effect the seal. I say this just because it seems like common sense and not because I'm a chemist or know enough chemistry to be any kind of authority.

 

Second, I think what the video shows furthers the points made by the guy I was talking to. The shaft going through the pump is functionally a lever. The tensioner applies force to the gear on the outside of the pump and the failure starts on the inside of the pump. The farther the shaft gets from the force applied at the gear, the greater the force gets. It shouldn't be surprising that failure begins inside of the pump because of leverage. The chain tensioner is designed to maintain the operation of the heads so how much thought was given to their effect to forces on the pump? My understanding from what I was told is that the wear pattern of the pump isn't the same as the what's needed by the wear pattern of the rest of the system to keep the operation of the heads in spec. Ultimately what I got from what he said was the pump operates better with it's normal wear then with the wear corrections induced by the tensioners because the corrections promote pump failure. Also the problems arise from the pump location more than the actual failure of the pump which doesn't seem unreasonable by mileage.

 

I did ask him how he came to these conclusions but he wouldn't say. That's not unusual though. Is this something he worked on, read or heard? I don't know but the nature of his work is proprietary and I don't think he would want to be responsible for any finger pointing because of something he said. Growing up a good friend of my dad's was an engineer that diagnosed vibration and he wouldn't talk about the work he did unless something became common knowledge. He studied things like hydroelectric dams though.

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Much of what you say may be true, as Ford redesigned the right-hand guide (not certain if this is a tensioner or not). But the do state it should be changed to the new style whenever the water pump is changed.

 

Thanks for the explanation, very interesting. I have 110k+ and bought an extended warranty to cover my upcomimg "potential" failure.

 

Must consider that mactfordedge ran two 3.5''s, 200k+ without failure. (Meaning that maintenance is a variable that is still a factor).

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enigma-2,

 

I agree. I don't think there is any substitute for recommended maintenance. I'm sure we've all heard the "old wives tales," and the latest, greatest homeopathic remedies for auto maintenance. I'll stick to the schedules and let the rest amuse me.

 

After I wrote my last I got to thinking about the videos. The guy talked about acids so I wondered what the Ph of antifreeze is. Turns out it should be around 9.5 which makes it an alkali. Acids are 0+ to neutral at 7. Makes me wonder what the guy was thinking when he mentioned acids eating at the seals?

 

I think what should be taken away from what the engineer told me was the cam chain runs more than one system, coolant and valve train which have different wear rates or patterns with an emphasis on the valve train operation. Mileage on the pump doesn't seem to be the problem either. The pumps on properly maintained engines are getting respectable mileage. The problem is where the pump is located when it does go. Accepting what I've read on the internet, it is located where it is because of space in the engine compartment and not because of some other practical benefit for putting it where it is. It's just one of the many compromises that go in to every car design.

 

I didn't mention this but I was more interested in his opinions on how to seal the pump permanently between the water and oil and installing an electric pump. His suggestion was to fabricate a billet aluminum cap with a oil impregnated bronze bearing\bushing the length of the internal side of the shaft, remove the impeller and Tig weld the cap in place. I have access to a shop with a CMM and CNC milling centers and I planned on looking in to this when I get the car running again. The other option is to reroute the chain off of the pump. I don't want to mess with that.

 

Electric pumps don't have the life cycle of mechanical pumps but considering the failures I've read about even with proper maintenance this seems to be a cost effective solution.

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I read about the electric pump concept, but I can't buy into it. The replace the existing water pump, you still have to tear the engine down. So the cost is the same either way. Replacing the water pump with a OEM pump will assure another 100-150k miles. Fabricating a blank and replacing with an electric pump may actually cost more, and not last nearly as long, but has the advantage of not killing the engine when it fails.

 

Perhaps a better use of money would be to design an early warning system to prevent catastrophic failure. Something related to using a stethoscope. Chain slap & worn bearings should be audible prior to total seal failure.

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enigma-2,

 

Your logic is right on but why I like the electric pump idea. The original cost will be more than replacing the conventional pump because either way the front of the engine has to be tore down. It's with any subsequent repairs that the savings would be overwhelmingly less. Electric pumps can also be repaired when they fail at a fraction of their up front cost.

 

If failures of the pump were limited to typical high mileage, end of life I would agree. From what I've read about the failures though there is a year range which includes my 08' where failures are common at any mileage. Unfortunately there isn't much information about failures due to age rather than mileage. My Edge is 11 years old but just turned over 40,000 miles. Can I expect to see the pump to last 25 years when the car might see 100k? I doubt it. I also keep my daily drivers, if that's what this car is, until their done. I understand the many reasons why some keep their cars for only so long and replace them but that's not me.

 

I have to add this too. I enjoy doing things like this. Even more so now that I'm retired and time isn't given the deference it once was. Where 2 weeks to replace a water pump would have been unacceptable it doesn't matter now.

 

As far as your idea of monitoring the pump with noise or vibration sensors should be easy enough to do. The difficulty would be with developing acceptable sensor ranges. If somebody has already developed this information it would make the idea much more appealing. Without it though, you'd have to do it yourself and that kind of bench testing comes with a cost that would shame any kind of costs as yet considered.

Edited by I'manedgeowner

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No one will make an electric water pump for the Edge, so it'd have to be custom. It' would definitely be cheaper just to run it and swap in a low mileage used engine if it blows.

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IWRBB,

 

You're right that I couldn't find a kit made for this engine but I did call Meziere and they said people have been using pump WP336S connected to the lower hose. They wouldn't suggest how to deal with the existing pump but people have been swapping out to electric pumps. I posted this in another post if the pump number is wrong.

 

I'm not too sure I can agree with swapping a used engine being less expensive. An electric pump with everything needed would be less than $400. Any future repairs to the pump would be $50 to $100 which would be much less than replacing the mechanical pump and the engine doesn't have to be touched. The aluminum needed will be no more than $10 to $15 and the machining won't cost me anything except the time to program the machining. This isn't even difficult anymore with the cad program built right into the machine controls. Cutting speeds and tool changes are even automatically programmed for you now. Granted, my aluminum welding can sometimes leave me wanting so I might pay for that but still I can't imagine it to be anymore than $30 or $40 at most if I start with a new pump that hasn't absorbed any welding contaminants.

 

There are some eco boost electric pump kits but for the 3.5 or not I don't know. The truck 3.5's have an external pump and I've wondered about those too. I'm not familiar with this engine enough to know how the coolant is routed in the trucks or if the front engine cover will fit on a car engine?

 

Just saw that the car has 39,754 miles but at 11 years old and all I've read about the pump problems I don't have much confidence in it's remaining life. This is an inevitable problem waiting to happen.

 

Edit: OK, Summit wants $438.47 for this pump with a universal mount and wiring. So a bit more than I said. I also have 2 Coyote Cobra Jet electric pumps already and I could try one of those.

Edited by I'manedgeowner

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