Sunday, April 16, 2017

Water Pump Dead=DOA? Not In A LEAF!

Normally I only charge just before going to bed. Its one of the last things I do and normally do it while I am brushing my teeth.  But the other day, I had a planned light day and had about 40-50 miles of range so didn't plug in that night.   But as life normally does, I had decided to do something with my time off that was a bit of a drive so I plugged in at home.

After about 2 hours, I went to the garage to retrieve a food item and noticed a faint high pitched squeal.  It was so faint, I couldn't tell where it was coming from but eventually determined it was the car.  So I popped the hood and it wasn't really that much louder but I immediately realized what I wasn't hearing.

In my previous LEAFs, I could hear a faint sound of rushing water. The water is used to cool the Inverter while it converts AC power from the wall into DC power that can be stored in the battery.  This was again very faint and easy to miss if you are not listening for it. In fact, many long time LEAF owners swore up and down that their car did no such thing....that is until they went out to check.

Now, I was concerned.  I do know that in some instances, the water pump turned on immediately and sometimes it took a while but I had been charging almost 2 hours and with my fastest charging option yet, my Clipper Creek at 24 amps! (previous options were EVSEupgrades at 12 and 20 amps)

So I put my hand on the PDM (its the valve cover looking thing) or power distribution module which houses the inverter along with several other components, and it was warm. I was immediately shocked. In all the times I have charged including during 100+º  heat, I have never felt anything resembling warmth before.  In fact, the underhood area is so cold that even Mice avoid it!

I unplugged the car right away thinking water pump failure but knowing this DOES NOT MEAN BEING STRANDED like a gasser would have been. That pretty much put a smile on my face for the rest of the day. My mood got better and better as the day went on. I think my making a point to everyone I talked to that my water pump went out and I was still driving the car and watching their reactions might have had something to do with it... :)

Anyway, as luck would have it, I was working in Bonney Lake which meant driving right past Bill Korum Nissan in Puyallup and the best LEAF tech in the region, Aaron McAfee!  This was simply too convenient!

So called up their service dept, set an appointment for 2:30 and kinda hoped that I would be close to making that time. I was on a Rep client job which means I have to work at their pace which usually means slowly and inefficiently and this was no different. And we were doing 3 locations to boot.  Luckily I was able to get out on time despite taking a 45 minute lunch 2 hours into our day. Since the first two jobs were in Puyallup, I was less than 2 miles away from the dealership and had a brief thought of running down there early to see if they could fit me in but in my previous experience with dealerships combined with the fact that I would be a first time customer there, I figured there was no way.

Anyway, after the job was completed, I went to the dealership arriving 15 mins early. I pulled up to the service area and sensors automatically opened the service bay doors. As I was exiting the vehicle, I could hear Aaron being paged.  I guess they were expecting me!

My total time at the dealership was roughly 20-25 mins. This included check in,  brief explanation of what I was seeing and what I suspected and the diagnostics which included collecting data to confirm and the MOST time consuming part of the visit. BSing with Aaron over the general state of EV affairs and the LEAF.  In reality, I could have been easily out of there in under 15 minutes if I was in a hurry. I have never seen a more efficient process along with a service department that valued my time more.  I know I am preaching to the choir here but if you want the best for your LEAF, take it Aaron at Puyallup Nissan!

Anyway, Aaron plugged the car in then started monitoring temperatures and it was confirmed that the pump was running but not moving much water. The squealing sound was likely the pump running at full speed.  The pump was also vibrating meaning one of the impellers was likely broken. He mentioned he had already seen a few of these.

This could be a concern.  There was no codes thrown and this could eventually lead to inverter failure which is a much harder part to get. (Water Pump should take a day or two to arrive)  Now, before anyone freaks out, the BMS would slow the charge rate down if the temperature got too far out of control but I wasn't really willing to take the risk and with NCTC, I was ok with shifting most of my charging (well, kinda already was... :) ) to DC only until the pump was replaced.

Either way, I think this is something LEAFers should check on just in case. Better to be in front of this then to be stranded, right!


  1. I expect this type of failure to happen more to people using L1 as their primary charging method, just because the moving parts are going to have a life in hours, and L1 means more hours of the pump running

    1. Not necessarily. The pump has an adjustable duty cycle so lower heat demand means a slower less taxing running speed. I think Aaron mentioned its best speed and the speed it normally runs at is 70%

  2. thanks for sharing...
    The pump has an adjustable duty cycle so lower heat demand means a slower less taxing running speed.