Anyone ever had to change this? I got a fault code P2601 on my car the other day along with limp mode and the Restricted Performance warning on the dash. The warning and fault code went away themselves after stopping for a bit but limp mode persisted until after I'd switched the engine off for a while and started again.

A bit of research suggests the pump could be on the way out or wired wrong. Given my car isn't exactly new I suspect the former so planning to change it. So some questions...

First, am I right in thinking the S/C coolant circuit is independent of the main engine coolant circuit? Second, the workshop manual says to drain the main coolant via the drain plug on the main (I guess) radiator and then disconnect the two coolant hoses at the top. I suspect that's just to access the screw holding the pump in place - if so, is it possible to get at the screw another way and negate the need to drop the main coolant from the car?

Any help/advice gratefully received...

 

I'm not familiar with the P2601 code but I would pop the fill plug (cap) off with a 17 mm Allen wrench and make sure it has coolant before digging further.

 

Thanks, I'll take a look in there.

 

Usually it is possible to clamp off the inlet and outlet hoses on the intercooler circuit pump and replace it without having to drain the coolant. The intercooler system is connected to the main coolant system, at least on the 2012 models. It is important that you properly bleed the system after replacing the pump or you could get cavitation and improper intake charge cooling. I used a Bosch 010 pump, it is around $100.00 and flows around 10% better than the Hella unit that costs $350 - $400.

 

So I checked both in the expansion tank and inside the filler plug on the S/C intercoolers, plenty of fluid in both. So it's not leaking or otherwise losing fluid.

I understand this pump should run all the time while the ignition is on - if I switch the ignition on with the bonnet (hood) open and listen in that general direction, I hear the a noise like a smallish pump running for a couple of minutes, then it stops. Not sure if that indicates the pump is failing or it's just noisier on startup.

Another thing - I took the car out last night to drop some stuff off at a friend's house. I was just driving in town, never exceeded about 40mph and didn't accelerate hard. I opened the bonnet when I parked up to double-check the coolant fill plug on the intercoolers as I'd had it out the other day and the intercoolers were too hot to touch. I don't recall them being that hot, even after a prolonged and/or spirited drive in the past.

So I guess this is looking like a bad pump, right?

 

Yep, sounds like it's not pumping fluid. I would take the time to verify power to it or jumper it out at the pump to isolate it between the chassis and the pump. My coolers are almost cool to the touch after running on a 80` day. While using the scan tool at idle I read the sensors and was getting a 40` temp drop across the coolers.

Oh yeah, by mistake I fired up the car with the I/C filler plug off and coolant came out. Not sure but suspect it was from the I/C pump and not a hidden 'fill' line from the main cooling system.

 

Cool, thanks for that. Today I had to drive a few (maybe 15) miles out of town for work. I monitored intake air temperature using Torque Pro on my phone and a bluetooth OBD adapter. By the time I parked up I saw intake air temp of 83 celsius. That was after mostly cruising to a max of 70mph, no real hard acceleration. I'm not familiar with typical IATs on this engine (ambient temp was about 20 celsius) but I think that might be a bit on the high side?

The workshop manual says that after filling the main cooling circuit via the expansion tank, to then remove the I/C filler cap and turn on the electrics (not the engine) as this will start the S/C coolant pump. It does say that this may make coolant spray out of the fill point, but to then add coolant to the fill point while the pump is running, this is how one bleeds that part of the circuit.

 

IAT is (a long way) before the IC (SC) pump. Or are you watching IAT2? (My car has one so I expect yours has too.) Not a standard OBD item but readable with some effort (on my car).

 

Hmm, that doesn't make a lot of sense surely? The charge air goes directly from the supercharger into the intercoolers - why would they bother monitoring the temperature of it in between the two? Not sure where else in the intake air system the air could possilby reach that sort of temperature except post-supercharger?

 

You'd have to ask the jaguar engineers (let us know if you find any way to contact them!). Consult workshop manual and wiring diagrams and see - very easy to grasp where IAT and IAT2 are for my car's version of the same engine.

The answer I think is that by cross-checking IAT2 with IAT it can tell whether the IC pump is achieving anything (and throw P2601 etc if not) and also tell what to do with timing based mainly on IAT2, but I'm not programming the PCM so just thinking what I'd do...

 

So it looks like the MAF sensors (X150 XKR has two intakes with one MAF each) have an air temp sensor in them, and the MAP (manifold absolute pressure) sensor has one also, that's the one referred to in the X150 workshop manual as "intake air temperature sensor 2". So if it's the reading from one or other MAF sensor that's being presented via OBD then I find it unlikely that could be reaching 83C as it enters the car.

Having said that, I am seeing a fault code for a MAF issue so I guess that might explain it. Actually, on that note - I wonder if the MAF/IAT sensors giving dodgy IAT readings could cause the car to think there was a S/C cooling pump/circuit problem when there really isn't?

 

If any critical sensor (incl. an IAT) is wrong then bad things happen.

Many wrong sensors cause codes but there's always some value that might be plausible so fools the PCM. (Which can't look out a window and realise 83C is just not right!) Or the software is a bit limited (they ran out of ideas or ROM space).

 

Update time. I changed the pump on Sunday - what a royal pain in the rear that was, access is very tricky from any angle, the whole job took about 8 hours in the end.

Anyway, pump and coolant all changed, IATs now rise to around 40*C and hold around there, +/- 2 or 3*C depending on how aggressively the car is driven. So I guess the IAT as reported via the OBD system must be the one taken from the sensor post supercharger/charge coolers, not those integrated into the MAFs.