Supercharger cooling
 

Car is an 04 STR (facelift).

My car has been off the road for a while as it had a coolant leak which I traced to the water pump, a P2601 fault code connected to a restricted performance warning and the trigger for garaging it, a failed headlamp. Today I thought I'd bite the bullet and fix everything. There's a little bit of history in that the car was worked on previously by a suspect garage. I had reservations but hadn't been able to pinpoint anything they had done wrong. More of that shortly...

The water pump is relatively straightforward and despite what the manual says, it can be done without removing the supercharger drive belt. Extracting the old pump and inserting the new one is simple if you unbolt the thermostat housing.

The headlamp bulb is also easy enough but does require front bumper removal which is a 15 minute job once you know what you're doing.

The supercharger coolant pump was a different story! Firstly, I cannot for the life of me get eyes on the electrical connection for the pump. It's relatively short and therefore can't go far but disappears out of sight under the chassis rail and I can't see it from any angle. Does anyone have a photograph that will save me taking more and more of the car apart? The connection is highlight blue in the last photo.

However, the real interest surrounds an unusual bodge which is probably connected to the P2601 and may be my problem, not the s/c coolant pump. Looking for the connection for the coolant pump and tugging on hoses and wires to try and see it, one thin hose was clearly tucked away.

It starts from the supercharger radiator and the connection is highlighted in this photograph:

https://cimg0.ibsrv.net/gimg/www.jag...9d0a6eb67c.jpg

But things were much more interesting on the other end of the hose! Have a look at this:

https://cimg8.ibsrv.net/gimg/www.jag...2477ea16ec.jpg

Now I can't think why they would do that but I'm more interested in returning it to its rightful place. Am I right in assuming that should be connected to the expansion tank and that it's item 3. in this diagram? I ran out of time to left the expansion tank so God knows what I'll find under there.

https://cimg0.ibsrv.net/gimg/www.jag...79f1c2df27.jpg

As always, any help greatly appreciated.

Someone put on a non supercharged tank at some point....that hose goes to a fitting on the upper part of the correct tank....the intercooler pump plug should be accessible by removing the right front tire and then the plastic inner fender guard....or you can jack the front end up and take the underbelly cover off and access it from underneath....there are 3 plugs attached to a holder...one is the fan plug...one is the intercooler plug and I can't remember the other....either way you choose you will be able to access the pump and trace the wires...the intercooler pump is mounted low on the core

Thanks. Will take a look at the tank later today and see what I have. It's annoying because I had to purchase a new tank a couple of years ago and that may have gone missing at the garage...

I'll take a photo and update the thread.

Sounds like I need to get into the wheel arch to access the pump connector - thanks for the pointers.

The correct tank is the same as the n/a engine's except for the extra fitting....some suppliers will have a photo of the wrong tank with the right part number....if you do have to buy a new one, I suggest brand new from one of the forum sponsers....that plugged hose is the overflow/vent for the supercharger radiator...being plugged could possibly lead to airlock and reduced flow...if you are replacing the cooling pump, I suggest the Bosch hi flow...don't have the part number handy...it is on eBay...you have to do a slight wiring mod and secure it to the bracket with zip ties....nothing major ...it sure improves coolant flow and intake air cooling

You were right. Definitely the standard tank fitted. As it happens, I have a photo of the correct installation before this bodger got his hands on the car.

Seems like too much of a coincidence for me to get previously unseen Restricted Performance problems and coolant pump codes. I have seen threads on the revised pump fitting but I think the first thing I'll do is fit the correct expansion tank tomorrow, get everything connected up, clear the codes and see if that resolves everything. I'll leave the bumper off and if the coolant pump is still a problem I do have a replacement in my spares box.

And that can lead to air lock in the cooling system. But check the sc pump for operation because restricted performance does hppen for open or short to ground in the pump circuit

On brutal's note...double check the big plugin where the 2 wire plug for the supercharger pump connects to....unplug it and check for corrosion or broken pins.....it happened to me...there is a thread on here but I do not remember the key words

Thanks guys. Ran out of time to test anything today but got the new expansion tank in and will run everything up tomorrow.

Incidentally and answering my own earlier question, I could see the supercharger coolant pump connector with the expansion tank removed. I've now re-routed the wiring , possibly to where it really belongs, so that the connector is accessible from underneath.

In the spirit of avoiding loose ends...

I changed the expansion tank, refilled the system and found that the original coolant pump runs so I'm leaving it for now.

However I am getting a persistent P0322 knock sensor code and the car goes immediately into restricted performance mode on startup.

I can clear the code whilst the engine is running but it will come back on instantly. Interestingly I cleared the code before starting the car this morning and on starting it took about a minute before the car went into restricted performance mode and threw the P0322 code. It's now instant on starting again.

I know the charger has to come off to change the knock sensors and although I'm confident I can do it I would rather be doing other things.

So before moving my bed into the garage for the next couple of days I'd appreciate responses to a couple of questions. I will also try and do the pinpoint tests in the manual as I know it's foolish to start with replacing items without a proper diagnosis.

A little more info is that I have looked at the throttle body connections. The big one at the rear which is mounted vertically seems dry and sound. There is a smaller connector mounted horizontally where the male end is in very poor condition. I think this powers the TB motor but it must be working or the car wouldn't run. Fair conclusion and/or could it cause other problems?

I have never had problems with knock sensors on other cars before. The car is not pinking or running badly. Am I right to suspect a faulty signal or wiring above the sensor itself? When it took a minute to go into restricted performance mode after a very cold start this morning I could not detect any noticeable change in engine sound or running before and after.

Can anything else trigger P0322?

The only other background I can think of is that I have a suspect cat on one side. This was throwing a below efficiency code but seems to have disappeared now, even though the car has been run up to normal temperature by idling for twenty minutes or so.

Fuel is low so I am about to top up with fresh.

I did fill via that bung - assume you mean the really big one with an internal hex? I haven't bled it subsequently though. Will take a look at that later.

How could that cause a knock issue?

Coolant leaking down into knock sensors and connectors are the most often reason they fail. I never remove that big plug to bleed, but prefer to vacuum the system and fill. Run the engine and let cool and refill if needed. You can try to clean the connectors iirc theyre accessable towards the front bottom of the intercooler or stuck the engine cover brackets that bolt to the cam covers. Clean them with contacts cleaner and check for circuit faults

I have never had to remove the big hex plug and my STR would self bleed over several days of normal driving.

But what I wanted to ask is are you sure you changed the right pump?
Do you know the car has 2 extra pumps? Both on top of each other and the IC pump is on the bottom and is more difficult to get to. We have had several members as well as professional repair places replace the wrong pump.
I think that's your problem.

Take a look at thread for in depth answers.

STR Pump
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Firstly, thanks for the suggestion.

Second, apologies for quoting a P0322 code earlier. It's P0332. Doh!

Feel free to comment on my thinking/logic as follows:

The bodge referred to earlier in the thread with the blanked off coolant hose could (would!) definitely cause the supercharger to overheat and throw a code/trigger restricted performance.
Fitting the correct expansion tank, reconnecting the plugged off hose and bleeding the system should have restored everything to normal UNLESS the pump itself was faulty or there is an as yet diagnosed electrical issue.
This is the original pump I have on my car.
https://cimg3.ibsrv.net/gimg/www.jag...d7867ed870.jpg

I believe it is working because it runs when the ignition is on and with the large hex filler plug removed and engine off I could see bubbles and movement in the coolant. However I do have a spare if required.
I have no problem with the heater which should rule out an issue with the other pump referred to.

I am still stuck with the car going into immediate RP mode and triggering the P0332 code. Now I have been gearing myself up to remove the supercharger to replace the knock sensor but obviously want to rule out all other possibilities before I do that.

I was looking at threads on how to remove the supercharger and would appreciate some clarification based on this pic:

https://cimg4.ibsrv.net/gimg/www.jag...269682e8a3.jpg


1. Am I right is assuming the two circled components are the knock sensors?
2. Is there any variation on the type pictured? I appear to have discovered another monumental bodge which I will post up later when can upload some pics.
3. Is my numbering correct for 'bank 1' and 'bank 2' or should it be the other way round? P0332 refers to the knock sensor in bank 2 but the bodge I have referred to and I think is responsible for the code is definitely pertaining to the bank I have numbered 1. in the pic.

Thanks in advance.

Yes those are the knock sensor. And be sure to torque to the correct specs as too tight makes them to sensitive, and too loose not enough. Replace the hoses while there and since you're there i would replace the intercooler to head gaskets since it only a handfull of bolts. A restricted perf set with ket on engine off or at first startup almost certainly ponts to electrical failure of the part,/circuit and not a range performance issue.
AND why not put a smaller sc pulley on to up boost 3psi and bring it in sooner in the rpm range. you can thank me later. :)

How much soft carbon deposit was on the elbow below the TB? The inlets to the charge coolers look pretty black. There will be at least as much soft carbon deposit in the charge cooler matrixes as in the elbow.

jaghelp.com: 2006 S-type supercharger removal......check out this thread...it is very good

The pump in your picture, the one you're holding in your hand, is the heater pump, not the intercooler pump.

Thanks for the replies. However, can someone confirm my numbering of the banks in the picture is correct? What I'm finding indicates they may be the other way round.

Firstly though with regard to carbon build up, I should say the last two pics aren't of my car. They are pasted from other threads.

Brutal - I will definitely go belt and braces if I remove the supercharger but that may still prove to be unnecessary.

The starting point was that I had an impossible to clear P0332 code which refers to bank 2.

Once I knew where to look I traced the wires from each knock sensor back to their connectors in front of the engine. You can see them in the picture below the circled knock sensors. The one on the right (bank 2 as I have numbered it) seemed normal with no damage or water ingress. However the one on the left (shown disconnected in the photo) was connected but also had a duplicate male connector end sitting next to it. Tracing the unconnected wire back showed that it disappeared under the front of the supercharger so must be the knock sensor lead for that side. So what the hell was connected to the loom? Pulling on the wire brought this little beauty into the open:

https://cimg2.ibsrv.net/gimg/www.jag...04f2a99cf1.jpg

So I had the knock sensor for a different car (looks like one for the 4.0) attached to my loom but not connected at the other end anywhere, just stuffed behind the hoses. I also had the correct knock sensor (based on the wiring, connector and position) left unconnected! This is much harder to understand than why someone would plug a 'spare' coolant hose when they realised they had fitted the wrong expansion tank.

​​​​​​As you'd expect, I quickly made the correct connection and went to start the car, fully expecting something positive. Well it wan't positive but I do have a change. Before I reinstated the connection I was only getting a P0332 code with RP. I cleared the codes and on starting up I'm still getting the instant RP but now the P0332 has gone and it's throwing TWO codes - P0333 and P0327.

So from having a code on one bank I now have codes for both. Intuitively this is feeling like a wiring or trigger issue from elsewhere rather than two faulty sensors but what do you all think?

Picking up on the comments about the coolant pump I ran the engine up to temperature (it is most definitely not knocking or pinking). I found that the supercharger radiator bottom hose was stone cold. This suggests an air lock to me. Do people agree? I can't find a bleed procedure for the supercharger so would be grateful for any pointers.

It may be that the one in that picture (as I said, not my car) is very similar to the intercooler pump but the one I mean is identical to this one:

https://www.ebay.co.uk/itm/SUPERCHAR...-/272373935929

It sits low at the front and runs all the time the ignition is on. I'm sure I have identified the intercooler pump but apologies if my pasted photo is misleading.