Topping off supercharger coolant, is my pump dead?
 

Anyone ever top of the supercharger coolant through the 17mm plug on top?
I tried doing this as the manual said, ignition on should keep the fluid circulating , but in my case with ignition on fluid just sits there , no movement. Is my pump dead ?

I got an error code earlier today, and a big red warning in the dashboard display. The dashboard display said "operating in restricted performance mode" (I'm paraphrasing. I forget the exact wording) and the P code on my Torque app said something about the coolant pump not communicating, or not responding, or something like that. I didn't write down the code number. I was on a long drive up to the mountains and I was just hoping the car wasn't going to overheat.

Anyway, I cleared the code and did a hard reset (disconnected the + battery lead and held it to the - battery lead for a few seconds). Everything went back to normal.

If your pump was dead I would assume you would get some sort of code/dashboard warning like I did.

However... I just realized I have a 2010 XKR and you have a 2008. The 4.2 liter engine might be different in regards to the codes.

No light on mine , yet no flow noticed either with the plug open

On my 2005 XJR that plug is at a "dead end" high spot. There is no flow at that point.

The aluminum pipe leads up to the plug and just beyond the plug a hard dead end.

However my SC pump runs all the time the ignition is on so can hear it running.

Should be the same or similar on your car I would think?

Hmm I'm just going for the service manual which says that there should be movement

In my workshop manual it does not mention anything about movement. Just warnings about overflow if engine is running.

With the engine off I thought I could feel the aftercooler hoses pulsing a little when the pump was running.

But yeah, don't start the car with the Allen bolt cap out...

The s/c coolant pump on my 2008 4.2 failed a couple of years ago, I hit restricted performance after a few minutes of driving. There's a fuse for the pump in the engine bay fuse box, check that out (it's listed in the owner's manual). I found the fuse blew almost immediately after changing, confirming a failed pump.

After I changed the pump, when refilling with coolant per the workshop manual procedure, I also didn't see coolant flowing past the fill port. I worried a bit at first but after some test drives, monitoring the intake air temps using Torque Pro and not seeing them go anywhere near as high as they did with the failed pump I decided that this was nothing to worry about.

Ok so maybe my is ok. Did you upgrade your coolant pump ? You notice what your temps were before and after ?

If you're not going into restricted performance mode by about 20 minutes after starting the engine every time then you're probably OK. Even just gentle cruising at low RPM would get it hot enough to hit limp mode. I did get a fault code, P2601. No EML though, just the restricted performance warning after about 20 minutes or so driving. When I was watching the IAT values I was seeing it hit around 85 celsius, that's when the car would go to Restricted Performance. IATs held around there until shutdown.

I just replaced with an OE pump. The car was standard; no tuning, no pulleys etc. and here in Scotland, ambient air temps seldom go far above 20 celsius. I found one at a breaker, pulled from a low mileage 5.0 XKR, the part is the same through all the 4.2 and 5.0 XKR models, C2C1314. New price is a slightly insane £387. This was some time ago now but I seem to remember IATs sitting around 40-50 celsius once it was replaced, depending on load, ambient temp etc.

How difficult was the coolant pump replacement?
I think I might want to do this as a preventative measure anyways

As always, it depends on how handy you are with spanners. I'm definitely in the amateur leagues and it took me several hours. The workshop manual explains it in simple terms but it doesn't say you should remove the bumper cover - you might get away without that if you have very small hands but I couldn't. Beyond that it's draining the coolant, a lot of removing of hard-to-reach hoses and clamps and then figuring where the heck the electrical connector for the pump goes.

I'm not sure I'd bother as preventative maintenance. I haven't read of many of these failing and those that do have done around the 100k mile mark. You could spend the $350 or whatever it'd cost you to get a new pump, go to the trouble of fitting it and the following day something else goes wrong. If it fails, you'll know about it - the constant Restricted Performance warnings and the fault code will be a dead giveaway.

Did you go with the higher capacity version from the Mercedes or Beamers?

Yes bosch 010 pump is 100 shipped

I also would like the extra cooling since my car is modified

The Bosch pump is not a direct fit; I received one of those before I got the standard item (SNG Barratt here in the UK were selling the Bosch ones as an OE item despite the fact they weren't a like-for-like replacement), the Bosch part is larger than the original so won't fit in the mounting hardware on the X150. Also the original pump doesn't simply have an electrical socket on it, there is a fly-lead (about 20-30cm I think) which has a plug on the end, this passes back through a narrow gap and connects to another connector on the wiring loom. If you are going to use a Bosch pump you'll need to come up with some way of fixing it in-place (or relocating it) and making up an adapter for the wiring. My car was standard so I had no need for additional cooling so I sent this back and sourced a used pump from a low-mileage wrecked car at a breaker for even less than the Bosch cost here.

If I was you I'd start by doing some logging of your intake air temps, over a long, spirited drive or multiple strip passes, whatever you push your car hardest by. You're in San Diego, which I guess is a good bit warmer than here in Scotland and your car is likely producing more heat than mine did but it could still be that the juice may not be worth the squeeze. Often times I see people fit "upgrades" that really don't bring much benefit at all. I can't say if these Bosch pumps really do or don't help - yes they'll accelerate coolant flow around that part of the circuit but there are more components at play, e.g. the fan, the rad, the charge coolers themselves - just that I always want to say irrefutable, factual evidence of supposed or claimed benefit before I'll make a modification or recommend others do the same.

I got under the car today there are two pumps there one underneath lower corner of the radiator and another one a little bit higher closer to the cooling fan. Which one is it?