Sunday, April 30, 2017

Water Pump Replaced!

As mentioned previously, I discovered my car making more noise than normal and found out the water pump was not performing up to par.  This however only seemed to be an issue when charging on L2.  It seems the motion of the car which creates airflow thru the radiator, etc. was enough to prevent a lot of heat buildup.  After several long jaunts, the top of the PDM was completely cold to the touch. There was not even the slightest hint of heat.  Fast charging also did not affect temps at all including the motor temps. In fact, the motor temps dropped several degrees during fast charge sessions.

But charging on L2 means standing still and you could feel the warmth building in less than 15 mins. While waiting the few days for the replacement pump to arrive, I decided to do a test so went to local Harbor Freight in Lacey  to get their $18.99 Infrared Thermometer and was thwarted! They didn't have it. Only the $27.99 version. Well, as luck would have it, I was working near the West Tacoma Harbor Freight so went there the next day and despite being a much bigger store, they also only had that option.  I decided waiting for an online order wasn't going to work so I just bought it and found out at the register it was a 20% off sale that day so it only cost me $22 and change. It was so nice of Harbor Freight to recognize my dilemma and split the difference with me!

Now that I had tools, it was time to experiment! It was VERY hard to resist the urge to stop at Tacoma Mall for a free charge but it was all in the name of science, right!

To reduce outside influences, I let car sit in garage with hood up for 2 hours to acclimate and it did a good job with PDM case registering 62.5º with garage temp at 61.8º  with probe roughly 44" off the ground.

My EVSE is a Clipper Creek LCS-30P @ 24 amps plugged into 30 amp dryer Socket installed specifically for charging. (My dryer is actually inside the house)

Since I had the thermometer, I measured literally everything.  The J-1772 handle went from 63.0 to 70.5º during the test, the EVSE brick went from 73 to 102º F.

The test ran 2 hours and measured every 30 mins plus or minus one minute.  For the PDM, I measured the highest temp from top and then on the side around the seam.  With minimal water flow, the temps did have a bit of a range to them but less than I expected. The heat was conducted rather well.  During the test, the garage temps dropped to 58.7º by test end.  As luck would have it, LEAF Spy came out with an update that provided several temps as well but didn't really go off as expected but motor temps were available.

The top PDM temps    were;  62.5, 76.0, 85.5, 87, 92.7.
The side PDM temps   were;  NA, 83.0, 91.5, 95.0, 100.0
Motor temps logged from LS; 73, 93, 99, 102, 106

A few days later, I went to Puyallup Nissan and got the pump replaced and Aaron McAfee did verify a broken blade that hampered operation.  I declined a fast charge (cause I wanted a low SOC for a good test) and took it home.  I didn't have the time to wait the two hours because of an early work schedule the next day so let it sit an hour.  To help cool things off, I left the garage door open for most of that time.

This test ran 2 hours and 44 mins. (Basically to bed time) The garage temps started at 58.6º and finished at 61.5º at 8:23 PM.  I was less regimented with my time checks since it was mostly around the normal day to day stuff I needed to do but started at 5:39 PM and checked at 6:07, 6:42, 7:28 and 8:23.

Top PDM;  67, 75,  82,  84,  88
Side PDM; 68, 80.5, 85, 92, 97
Motor LS; 81, 84, 93, 99, 104  

So the results? Well, I should have collected more "before" data to really make a conclusion but at the same time, I was unsure of how much abuse the system was willing to take and didn't want to push my luck.  But if we take this one off data, it appears the max temps don't change much. But one BIG change is the "non scientific" test.

The pump outlet hose I could literally squeeze nearly completely flat with the defective pump. There was barely a sense of movement then. But now, it was all I could do to compress the hose a few millimeters.  The hose was full with pretty good pressure and you could easily feel and hear the water moving.

Now it still amazes me how cool the entire system remains while driving so I guess the radiator is really doing its job!

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