I bought a 2013 Ford Edge, used, in 2015. It is in great shape and priced great. I thought I had done adequate due diligence, but I must not have, as I completely missed the fact that the water pump is in the engine, run off the timing chain. Try as I may, I cannot fathom what idiot engineer decided that’s a good idea. Last I knew, water and oil don’t mix. Any insight as to how this became a good idea? Had I known this fact I never would have even considered that purchase.
This “good idea” was first done with the Chrysler 2.7L V-6…with terrible results. I guess since you already own the car, the smart thing to do is to replace the water pump and timing chain set every 100,000 miles, like you’d normally do with a timing belt. This is likely to cost around $2,000, but far cheaper than replacing the engine.
It’s very common to see that with cars that have timing belts, because – why not? Gotta replace the belt anyway so it doesn’t hurt anything to put the pump there. But I agree, it’s really dumb to do it with a timing chain.
That design doesn’t seem to result in problems as far as posts here go.
Do the usual due diligence: monitor oil and coolant levels and condition. If you see evidence of coolant and oil mixing, get it fixed. I would not spend the time and money to replace the water pump as preventative maintenance.
The water-pump on my 1990 and 1998 pathfinders didn’t run off the timing belt, but to replace it you had to remove the timing belt. I replaced the pump every other timing belt…never had a water pump issue. If I didn’t replace the timing belt myself, then I might have had the pump replaced every time the belt was changed.
Probably the same engineer that worked for GM.
This guy’s got the engine on a stand.
Imagine replacing the timing chain/water pump with the engine in the vehicle.
Yeah, I had a Mazda CX-9 with the same Duratec engine. If you wanted to change the waterpump, the whole engine and transmission had to be pulled out to the tune of 12-16 hrs labor. Not a DIY either!
A few reports of engine failure with the pump leaking coolant in the engine oil.
Our needs changed, so I sold the car at 65K miles.
My father’s 2011 Taurus SHO met and untimely demise due to that design. The water pump failed, dumped coolant directly into the oil pan, the main bearings were shot shortly after, by the time my dad realized what happened the engine was junk. He sold the car for around $2500 IIRC for someone who wanted it for parts.
2006 Pathfinder I own has water pump driven from the timing chain and when I was working on the engine front with 160K miles on it (stupid plastic tensioners on secondary chains!), the water pump was looking like it was just off the factory, I replaced it anyways
on Pathfinder’s engine, water pump has special OVERSIZED weeping hole and channel bringing weepage to the front/outside, so it is visible as a green/blue crust, no chance to get coolant mixed with oil
I do not see anything “criminal” with such type of design - as long as coolant is replaced on proper time/mileage interval, it should last as long as the engine itself
Or the timing chain?
the “main” chain is still original: it was not stretched even to get to the middle of tensioner teeth, it was no reason to replace it
the trouble of Nissan’s 4.0 V6 is on secondary chains, which interconnect camshaft sprockets: the OEM manufacturer had worn dies and many “lucky” owners discovered that after 80-100K miles, once these chains iwth sharp edges ate the plastic tensioners: $1 parts, but it is so much labor to get there, that you replace secondary chains and everything you might suspect you better replace so you don’t go there again
The coolant is inside a closed system. It won’t mix with engine oil unless the water pump housing fails. I imagine that Ford did this to save room outside the engine for other equipment. It’s crowded under the hood, as I’m sure you know.
Or the shaft seal. Or the gasket which seals the water pump to the engine block. In any case, by the time you see coolant in the oil, the engine is probably ruined.
All car manufacturers are guilty of the WTH were they thinking scenarios.,
Almost everytime I have no idea why they did this or that stupid thing, I realize most of the time the engineers put a large part of their designing into methods the make the easiest and quickest way for assembly of a vehicle. The faster they can assemble a vehicle, the more profits are to be made. Maintenance be damned. But once in a while they throw in a caveat and put a hole somewhere to make a ratchet and extension able to reach a hard to get to bolt or something.
Consider this in defense of the engineers…
A timing chain is more reliable than a serpentine belt. The water pump acts as a damper to settle down timing chain harmonics. If the weep hole doesn’t leak into the oil pan, the only downside is the difficulty of reaching the pump.
My 140K mile truck got a new water pump a few weeks ago ONLY because the bolts broke off in the T-stat housing which is attached to the water pump casting when I decided to pro-actively swap the T-Stat because it was so old. All during a coolant (Dex-cool!) change. So it got a new pump, T-stat, Serpentine belt and AC belt.
May be more reliable, but no where near as serviceable. I’ll take an engine designed with the water-pump driven off a serpentine belt any day over one driven off a timing belt or timing chain.
I’ve always been of big fan of KISS - Keep It Simple Stupid.
I agree but I’m also a big fan of parts doing double duty. Makes the design all that much more efficient by reducing parts count. If using the water pump as a timing chain damper, you eliminate the chain damper and its contribution to the overall reliability. Same for water pumps driven off the timing belt. A great many water pumps were likely changed proactively because it made sense to do that during timing belt service.
I just used my own example of water pump life. 140K is longer life than a timing belt or serpentine belts… and maybe some timing chains as well! But I service my coolant.
All this discussion reminded me about the Ford flathead V-8. There were two water pumps–one for each bank. The water pumps were part of the motor mounts. Even 67 years ago, there were some strange things. My 1954 Buick had the distributor in the back of the engine against the firewall. I would stand on a stool to get to the distributor so I could replace the points and condenser. The Ford Y-block V-8 put the distributor at the front of the engine where it was easier to service.
I should also mention the enclosed driveshaft on Chevrolets through 1954, Buicks through 1960 , and even senior Ramblers through 1966. The rear axle had to be dropped to remove the transmission.