Inspect Your Water Pump

[CX-5um]

Okay so aprox. 1 year ago I brought my 2.5l Mazda6 in to have my tensioner replaced (did not have right tools nor knowledge on how to replace it myself at the time). During that inspection the dealership noticed the water pump was leaking and even showed me noticeable dried green leaks. Got everything even tensioner replaced under warranty for free.

Fast forward one year and periodic (every oil change) inspection by myself on the tensioner for the CX-5 and Mazda6 all has been good. I have been doing all my maintenance after both cars' warranties expired.

So what do I see today on the Mazda6's tensioner...no not leakage hooray...wait what that tiny bit of green stuff? Further inspection towards the areas surrounding the water pump had small amounts of green stuff seemingly sprayed vs dripped. Small amounts but my watchful eyes caught them. I used my wife's mascra mirror

Dammit!!! It was not there before.

So I research and what do you know I found this: https://static.nhtsa.gov/odi/tsbs/2016/SB-10092584-6903.pdf

Apparently the skyactiv engine's water pump has a weep hole. Trace amounts of green coolant like mine if actually normal. The bulletin provides some sample good vs bad water pumps (although samples are not our water pump). Bottom of Page 2 of 4 shows a sample of the weep hole of what I first thought was true skyactiv water pump.

If easy to wipe off = Normal.
If crusted = replace water pump.

Got it.

Indeed the blow off of the coolant was easy to wipe away. However I could not locate that elusive weep hole. I tried using my hand to feel around where I could not see. All I could feel is smooth metal and no crusted spots. My idea is to head over to a dealership or car parts shop to look at a new water pump in my hands.

In hindsight I think the dealership prematurely replaced my water pump last year. (dunno). The service bulletin indicates: "There is a concern that some water pumps are being replaced that are not faulty, due to signs of a very small
coolant leak from the bleed hole. This Service Bulletin is to inform you about the water pump sealing mechanism and the criteria if replacement is necessary or not."

 

[yrwei52]

Yeah Ive seen that TSB before, its not new. IMO we should not see any sign of leak around the weeping hole. If we see any minor leak in the area, that should be the sign that the water pump bearing seal is about to give up soon. Id start to prepare the water pump failure in the near future and replace it whenever theres an opportunity.

The weeping hole is located at the bottom side of water pump shaft casing.

 

[CX-5um]

Bulletin indicates:

A mechanical seal (A) is used for the water pump. This mechanical seal can seal coolant (B) by sliding a mating
ring (C) against a seal ring (D). When the sliding surface temperature of the mechanical seal is more than 248
F (120 C) while driving, a small amount of steam (E) is leaked and bleeds through the bleeding hole (F). After
drying, the steam leaves a green coolant deposit near the water pump bleed hole (F). This is a normal condition
and does not require water pump replacement. The water pump should only be replaced if there is an accumulation of crystallized coolant near the bleed hole.


My understanding is that if operating temps get too hot the sealing design allows some steam to blow off. In that case the mechanical seal is operating as designed. Should there be excess accumulation (crystallized) than that is a different story. That said my coolant levels are low...........consistent though. Always at the same level. I am not experiencing sudden loss of coolant. Just minute traces of green stuff and nothing heavy.

To minimize reaching higher operating temps I will top off with some FL22 to reach the max line.

Edit: I have a feeling my weep hole is illustrated on bottom right hand side of page one. The bulletin is probably showing multiple types of water pump designs?

 

[yrwei52]

Looks like CX-5s water pump is on the right side of the first two pictures showed in the TSB, the one shows the weeping hole F and a round cap seal under it. The TSB says the steam leak which left with dry green deposit is fine. But any minor coolant leak which is left with accumulation of crystallized coolant near the weeping hole indicates the failing water pump. To me, its the difference on severity of the leak. A frequent steam leak eventually will become a minor coolant leak, then the major one.

 

[MyFirstMazda]

I think it is based on how bad it is leaking. There is this video explaining it

 

[CX-5um]

^ cool vid.

I could not locate any leaks anywhere from the water pump's perimeter. In hindsight I believe a drop came out of weep hole, hit the pump's pulley and flung some coolant (some landed on tensioner and some landed on rear of engine bay). I have not noticed coolant levels go down drastically but will continue to observe. I topped off reserve tank and drove for 30-mins in city traffic. Torque pro indicates a steady 185-190 degree coolant temp.

 

[Avoidin Deer]

I think it is based on how bad it is leaking. There is this video explaining it

Thanks for that.

It's nice to know these things before there are issues.

 

[madar]

Yeah I*ve seen that TSB before, it*s not new. IMO we should not see any sign of leak around the weeping hole. If we see any minor leak in the area, that should be the sign that the water pump bearing seal is about to give up soon. I*d start to prepare the water pump failure in the near future and replace it whenever there*s an opportunity.

The weeping hole is located at the bottom side of water pump shaft casing.

+1. Every water pump I've seen leaking out of this hole has been bad. Basically, if it's leaking enough, it's not circulating anything.

 

[negusm]

Yeah, if this is a Ford design...that weep hole is definitely an early failure indicator.

 

[tibimakai]

Not all pumps have this hole? I thought, that they all have it and as negusm said, it should be an early failure indicator.

 

[yrwei52]

Not all pumps have this hole? I thought, that they all have it and as negusm said, it should be an early failure indicator.

Yes, all mechanical water pumps have this weeping hole. But those electrical water pumps such as the Dynamic Force 2.5L found on Toyots RAV4 may not.

 

[CX-5um]

Its been 4 days now. I've driven the car hard in manual mode getting into redline a bit, driven on the freeway, regular city driving....cannot find any traces of coolant from the weep hole or water pump in general. Coolant levels are still at Full Line. A bit of me wanted the thing to leak like crazy...as an extra excuse to go out and get a new car.......but no. Nothing bad to report.

Interesting observation I had using Torque Pro. The Coolant temps get hottest when at idle. I recall it at 190 degrees and steadily climbing to 212 when at idle in a parking lot. I then turned the AC on and it immediately dipped to 190 again. Revving the car a bit (with AC off) also helps but not sure how all this works (Perhaps the circulation of the coolant?).

 

[madar]

If there is a serious problem it will probably show up in hotter weather, if there's any problem at all.

 

[Kedis82ZE8]

Damn.... I'm not on here much there days. I feel for you... another thing to watch out for. I am resigned to watch the timing cover oil leak (at least the rear main seal is fixed), listen to the squeaky PDLs, squeaky front suspension, now more internal squeaks and rattles (turn up the radio) and those atrocious rear hatchback struts. I so wish I didn't have recall done on the struts as they are noisier than the ones on the '96 Ford "Exploder" I gave to my nephew. I am thinking about buying some new ones. No amount of lubrication helps.

Sorry for my momentary b1tch.... I am still keeping this rig but I had to express my frustration.... if I lose the AT, Engine or Rear Diff I will be creating a blog though....

 

[yrwei52]

Its been 4 days now. I've driven the car hard in manual mode getting into redline a bit, driven on the freeway, regular city driving....cannot find any traces of coolant from the weep hole or water pump in general. Coolant levels are still at Full Line. A bit of me wanted the thing to leak like crazy...as an extra excuse to go out and get a new car.......but no. Nothing bad to report.

Interesting observation I had using Torque Pro. The Coolant temps get hottest when at idle. I recall it at 190 degrees and steadily climbing to 212 when at idle in a parking lot. I then turned the AC on and it immediately dipped to 190 again. Revving the car a bit (with AC off) also helps but not sure how all this works (Perhaps the circulation of the coolant?).

Not saying your water pump is going very soon, but definitely its going to that direction. The condition of bearing seal in your water pump has deteriorated and cant no longer prevent some coolant or steam leaking out under certain pressurized condition.

IMO the finding of the coolant temperature is the highest during idle is because the capacity of radiator cooling fan which is running at the lowest speed at the time. When the AC is on the 2nd AC fan is on and the cooling capacity is almost doubled, which brings down the coolant temperature.

 

[yrwei52]

Damn.... I'm not on here much there days. I feel for you... another thing to watch out for. I am resigned to watch the timing cover oil leak (at least the rear main seal is fixed), listen to the squeaky PDLs, squeaky front suspension, now more internal squeaks and rattles (turn up the radio) and those atrocious rear hatchback struts. I so wish I didn't have recall done on the struts as they are noisier than the ones on the '96 Ford "Exploder" I gave to my nephew. I am thinking about buying some new ones. No amount of lubrication helps.

Sorry for my momentary b1tch.... I am still keeping this rig but I had to express my frustration.... if I lose the AT, Engine or Rear Diff I will be creating a blog though....

Yeah not much you can do or want to do on your minor oil leaks without warranty after so many tries. I hope all of the squeaks and rattles on your CX-5 is the exception, and I definitely would be very disappointed if the condition of my CX-5 is like yours.

Yeah that supposedly enhanced rear liftgate struts replaced by the safety recall are another disappointment. Mine have not been making noise yet as I almost never use the liftgate, but I can tell the replacement struts are getting weaker and weaker. I should trust my instinct when my Mazda dealer urged me to preform the safety recall, and declined it at the time!

 

[CX-5um]

Update: Upon driving above 4500 RPMs for sustained times is when the water pump weep hole leaks....the leak is now more pronounced. This is a 14 month old waterpump installed at dealer covered under warranty. Well warranty expired. I wonder if they changed it at all or simply wiped down the leak residue and sent me on my way? Skyactiv engines have very good water pump lifespans.

I went through my mobile mechanic to do the job in my garage to replace water pump, stretch belt, serpentine belt. Oh and he had a machine on his truck to perform a coolant flush to remove all old coolant and put in new coolant while eliminating air. He only uses Gates water pumps and belts as he's had no customer call backs on them. 12k miles/1 year warranty parts/labor on his work at $467 for everything. Dealer wanted $950 water pump replacement alone.

Been aprox 75 miles now. The oem water pump is on my desk as a paper weight .

At combined 190k miles between CX-5 and Mazda6 no other mechanical issues to report.

 

[MyFirstMazda]

Update: Upon driving above 4500 RPMs for sustained times is when the water pump weep hole leaks....the leak is now more pronounced. This is a 14 month old waterpump installed at dealer covered under warranty. Well warranty expired. I wonder if they changed it at all or simply wiped down the leak residue and sent me on my way? Skyactiv engines have very good water pump lifespans.

I went through my mobile mechanic to do the job in my garage to replace water pump, stretch belt, serpentine belt. Oh and he had a machine on his truck to perform a coolant flush to remove all old coolant and put in new coolant while eliminating air. He only uses Gates water pumps and belts as he's had no customer call backs on them. 12k miles/1 year warranty parts/labor on his work at $467 for everything. Dealer wanted $950 water pump replacement alone.

Been aprox 75 miles now. The oem water pump is on my desk as a paper weight .

At combined 190k miles between CX-5 and Mazda6 no other mechanical issues to report.

Does the OEM water pump have plastic or metal fins?

 

[CX-5um]

Does the OEM water pump have plastic or metal fins?

I have it in my hand right now...I actually cannot tell if its plastic or metal. If it is plastic it appears to be very durable. It's actually a cylinder with fins (imagine a a deep dish car wheel).

 

[tibimakai]

Bang the fin with a metal piece and see how it sounds? Low pitch, or high pitch?