In this post I will compare two sets of data collected from the same engine regarding the engine speed, water pressure in the cooling water system, and engine temperature. All the engine data is from digital readings via NMEA-2000. The engine has the optional water pressure sensor installed.
In a previous post I reported some observations I made in 2011 about my model year 2010 E-TEC V6 3.3-liter 225-HP engine. I noted:
Observed Cooling System Water Pressure
RPM PSI RANGE ENGINE TEMP RECOMMENDED PSI
750 3.8 - 4.4 180 3 - 5
1300 9.2 - 9.5 191 8 - 9
1300 9.0 195 8 - 9
1350 9.7 163 8 - 9
1400 9.6 - 9.8 189 8 - 9
3700 14.0 127 12 - 14
4200 13.7-15.4 129 13 - 15
The data show the engine cooling system was operating in the normal range of pressure, with a trend toward the high end of the recommended engine temperature operating range.
Below is the recommended water pressure range for the 2010 E-TEC 225-HP:
Water Pressure Chart E-TEC 225 2010
To follow-up on those observations, I recently recorded some new data in September 2017. Again, from the same engine, but now with 455-hours of run time, and a water pump impeller installed in 2014 (when the engine had about 330-hours run time). The impeller was installed with the improved procedure. (See below for link). The impeller has thus been running for about 120-hours and for more than three years. The seawater temperature for these observations was 65-degrees-F, about the same as for the 2011 observations.
Observed Cooling System Water Pressure September 2017
RPM PSI F° RECOMMENDED PSI
500 3.8 - 3 to 5 (engine just started and still warming up)
1000 8.8 172 7 to 9
1250 9.9 168 8 to 10
1400 10.2 144 8 to 10
800 6.6 177 5 to 7
Based on the comparison of the water pressure and engine temperature ranges, I infer that the water pump impeller is still operating in the normal range of performance, even though the recommended three-year-interval for replacement has been exceeded.
Based on the comparison of the two data sets, the performance of the engine cooling system is improved by the new water pump impeller installation procedure. An improvement of 50-degrees in lower engine temperature is seen around 1400-RPM, even though the more recent data is taken from the fourth year of use of the water pump, which exceeds the recommended maintenance interval.
On this basis, it appears the new procedure for installation has made a significant improvement in engine cooling in the E-TEC 3.3-liter V6 legacy engine. It also appears that the water pump impeller can continue to deliver good pressure and flow beyond the usual three-year interval recommended for replacement.
For more information, see my original article on this topic (now locked) at
The recommended installation procedure for the water pump impeller is available in PDF form at