Having recently had a couple of engine performance warnings, tracked down to the coolant pump. Yes, mine was right in the VIN range, the car went into Terrain in Hastings yesterday morning. It should have been Thursday afternoon but incompetence at Corfu airport and EasyJet technical problems conspired to get me into Gatwick, just over an hour late, and no chance to get to Hastings in time.

Anyway, on a beautiful sunny morning, a trip to the seaside was no bad thing and I arrived even before the mechanics. They were straight on the car and by 09.20 it was all sorted.....or was it. Well actually, no. Still getting reduced engine performance message on the test drive. Eventually, the "guvnor" took it off and was back in about 10 minutes. No problem as I was munching a very pleasant bacon sandwich, courtesy of a local Turkish restaurant. I know, I thought it was a little odd, but very nice.

When the guvnor arrived back he was pouring with sweat and the rear windows of the fatty were open. He'd run it with the heater on full to get rid of the airlock. He noticed a couple of burps from the heater and, no more warning messages. ! 1/2 days later and still no message so all is good.

The wiring had already been changed albeit with solder and insulating tape. They sorted all that out so now we are back to normal. Another fatty problem sorted  2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

You must have been unlucky , I changed mine last week and had no issues at all.These pumps seem to have a finite life but not hard to get at . 2008 MY Supercharged
Rimini Red / Jet
four zone climate
remote park heater
and no ugly kid windows.
magnus satis quod turpis satis

Well, I almost got though the whole weekend without a repeat message for "reduced engine performance" but this morning, on the M20, the dreaded bong happened, at about 90. This is a repeat of what went before the pump was replaced.

Any pointers as to where to look now? 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

Was the wiring corrected at time of fitting the new pump?

Clearly it's been replaced, but if the wiring terminals weren't swapped over, the new pump will be running backwards.

Josh,

The wiring had already been changed using insulating tape. This was put right when they fitted my new pump but it does need some tidying, which is planned for the next service in January.Maybe this will sort it. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner