I have an intermittent noise at idle, that I think may be the supercharger torsional coupling.
I can get the coupling, and the oil, but I don't know if I can remove the snout with the supercharger in the car.
I have looked at lots of supercharger removal threads, and downloaded the instructions for the STR. I am hoping that removing the drive belt, intake elbow, coolant tank and thermostat octopus will be enough.
Has anyone done this job? I changed the oil last year so I am hoping the bearings are good. Previous owner claimed to have had a bearing kit put in the supercharger to stop this noise, but it was present when I got the car. I changed all the bearings in the accessory belt idlers and tensioners and the noise went away.
It has recently returned, so I will look at the coupler. New ones over here are bright green, and apparently better than the original parts, because they are more resilient.

 

I pulled my supercharger whenI replaced mine, so I don't have enough knowledge to tell you that it can't be done with the supercharger on the car. I took a look at a spare supercharger snout I have and the trouble bolts would be -- looking at the pulley of the supercharger from the front -- at positions 5 o'clock and 7:30 o'clock. If you can get a flex joint of some type to get those bolts, then you can probably get at all of the bolts.

If you have replaced a supercharger before, removal is not too bad. If you've never done it, there's a lot of frustration to be had (e.g., just removing the false bulkhead is more work than it needs to be and there's two bolts to a bracket under the throttle body that if you don't know exist cause frustrating "why can't I take this off?" moments) but it' s not an impossible job. Tricky points are the EGR bolts, bad tings happen if they get stripped and they're at a weird angle.

Did you replace all of the bearings? There are 4 if memory serves: the supercharger idler, the supercharger tensioner, the accessory idler and the accessory tensioner. The supercharger tensioner is a difficult part to find but it does exist as a new part you can purchase (this is not the case with the supercharger idler, there you need to replace the bearing). To rule out idler/tensioner bearings, you could try this: remove the intake snout into the air box (leaving filter to MAF to intake plumbing alone) to give you some access and spray some water on the idlers / tensioners to see if that changes the sound when the car is at idle. If there's a sound change, you've found your source.

 

Thanks scooterforever for that very informative post. I am looking at the coupler, because I replaced all four of the drive belt bearings last year, which at the time got rid of the noise, so I thought I had solved it. A post on here gave the details of the bearings to buy, and I used a press to swap out all four. The total cost was NZD 70, and all the pulleys were metal so the process was straightforward.
I would like to avoid removing the supercharger, as I have read the posts and know 'the secret' to removing, which you have also mentioned, but am afraid of getting stuck with something I can't fix.
I will get the coupler and the oil, and see if I can get access to the snout bolts. Once the snout is removed, I can assess the bearings, and if necessary get them too. I have access to a press to remove and fit the pulley. If it turns out to be easy, then I hope to have contributed to the knowledge base.

Regards
Pete

 

Just an update:
I have removed the water 'octopus with the thermostat etc, and have bought a set of external torx sockets (only need E10). I started loosening the snout bolts, only to find that the lower bolts did not give enough room to attach a socket. I have ordered an E10/E12 torx ring spanner and when that arrives I will try to loosen the bottom bolts. I have read that it may be necessary to raise the front of the supercharger to get the bolts out, so I will investigate what is holding the supercharger to the top of the engine. Disconnecting the outer flange of the intercooler adaptors will allow the supercharger to be lifted slightly. I am hoping that will not cause problems at the back of the supercharger at the air intake end.
Has anyone else done this on an X350/8?
Edit: I've also been looking at the threads about couplers, and decided not to use the green nylon one I bought. I've found a genuine Eaton torsion spring one for about US$100 and have ordered that. I hope that it will be quieter than the nylon one. My motor has just over 200,000 Km on it and is just fine apart from what I hope is the coupler noise. If I manage to get the snout off, I will check the snout bearings.


Ready to start disassembly

Snout bolts and oil filler

Not sure about those bottom bolts

 

Excluding the soft and rigid hose connections to the throttle body, intake elbow and supercharger outlet ducts, the supercharger is connected to the engine directly and indirectly as follows:

Directly:

1. Two bolts at the front of the supercharger connecting it the engine (I think you indicated you removed these)
2. One bolt at the rear of the supercharger connecting it to the engine; this bolt is under the intake elbow

Indirectly:

1. The supercharger outlet ducts connects to both intercoolers (you indicated you had removed these bolts already)
2. The intake elbow that connects the throttle body to the supercharger has two bolts that hold the elbow to a bracket mounted to the engine
3. The EGR connects to both the passenger-side (US) exhaust manifold and the intake elbow

The point that you are at now, if you fully removed the supercharger you would have the following steps left (at least the way I do it, there are some other approaches):

1. remove the false bulkhead and cabin filter housing (the EGR to intake elbow bolts are easiest to reach from where the cabin filter housing was)
2. free the rear wiring harness from its bolt-on attachment point to give you room to move it around
3. remove the throttle body
4. remove the exhaust manifold to EGR nuts
5. remove the 8mm EGR to intake elbow bolts -- be very careful not to strip these bolts, and if you partially stripped the heads on removal, swap them with the throttle body bolts (it's the same bolt)
6. position the EGR out of the way
7. remove the two bolts attaching the bracket to the intake elbow, these bolts are at 90 degrees to the crankshaft and are on either side of the intake elbow
8. remove the 4 bolts securing the intake elbow to the supercharger (you may need to remove the PCV hose and air line that go into the intake elbow), then remove the intake elbow
9. with the intake elbow removed, you have free and clear access to the rear supercharger bolt (number 2 in my first list).

People have notched the rear bolt hole to enable easier future removal of the supercharger, but after having removed all the parts the first time, I found the second time goes much faster. Of these steps, I found 5, 7 and 8 to be the most time consuming and frustrating. Having various ratchet extension lengths helps. If you've never done it before a cheap ebay endoscope can be really useful.

 

Thanks very much, #Scooterforever, for such a detailed and useful list of steps. It seems daunting, but I suppose it must be do-able. I just hope I don't put myself in a place where I have to give up and trailer the car to a proper mechanic for fixing. They wouldn't like it very much, and my wallet would agree.
I didn't know, before starting this, that you could buy external torx sockets and ring spanners. This is the most modern car I have worked on to this extent. I thought my V12 was complex, but this is on another level.
Thanks again, kind regards.

Pete M

 

Well,
Getting on with the task of removing the supercharger. I have got to the part where I remove the false bulkhead. I've got it loose, but I don't seem to be able to get it out. It is catching on the left side (looking forward). Most of the instructions here seem to be on left hand drive cars, and as mine is right hand drive, the cabin filter is on the left (passenger) side and the brake booster on the right (driver) side. I think the plastic mouldings are differently shaped. Has anyone got experience of doing this? I will carry on and remove what I can before I get to the fun part of the EGR valve removal.


The shape of the moulding is preventing the right side (in the photo) from being removed.

 

I can't fully tell from the picture and my experience is with the left hand drive version, but I think the cabin filter assembly has to come out first. Have you taken out the cabin assembly? Assuming the RHD version is the same as the LHD version, you: 1. remove the air cabin filter, 2. remove the 4 10mm nuts holding the air filter housing in place, and 3. I think there's one more nut holding the housing in place to the electrical connector at the front of the housing. My memory is that you have to take the housing out first then the molding piece can come out. Also check for plastic clips down low, there's a few at the bottom.
You'll need the cabin filter assembly out anyway to make the EGR removal easier. Best of luck with it, looks like you're making progress.

 

Hi scooterforever,
Thanks for the quick reply. I've made progress since I posted. The bulkhead moulding was impeded by the two heater pipes into the firewall. I was able to push the upper one down and get the bulkhead out. Since then I have removed the supercharger outlet and the throttle body.
In the RHD car, there is more room to the car's right hand (for me driver) side as there is only the brake booster and master cylinder there. I haven't removed the cabin filter box, because a.) I couldn't find the bottom mounting, and b.) It didn't seem necessary. I can see the EGR mounting on the exhaust manifold, on the car's right side, and the top of the bolts for the EGR valve. The EGR bolts seem to be mounted from below, so they will be interesting, but I have bought a set of stubby swivel ratchet ring spanners as recommended by someone. I have a strong vinyl floor cushion that I have laid over the engine, and I can stretch out full length to reach everything. The front of the car is up on ramps so it's hard to reach everything and I am not tall! I am letting my penetrating oil do its magic on the EGR bolts and then will try and remove the valve. The underside of the throttle body and the intake elbow is quite oily.
Thanks again for your advice.

Pete M

 

Congrats on the progress. Once you're past the EGR you just have the 4 bolts for the intake elbow to the supercharger (a 10mm socket with various extensions helps here) and the 2 bolts holding the intake elbow to the bracket on the engine. The first time I removed the supercharger I had no idea there was a bracket under the elbow and I couldn't understand why the intake elbow would not come off with the 4 bolts removed. Once the intake elbow is off, you're basically there. Removal of the supercharger at that point is almost anti-climatic. Once you do have the supercharger off, take a look at 1. your knock sensors, and 2. the valley hose. If you see wear on those parts, it's a good time to replace them.

 

Thanks for that great information. Is there any reason why the intake elbow has to come off? I don't have the gasket for it. I have seen a write-up for an S-Type R on Jaghelp.com where the removed supercharger seemed to have the intake elbow still attached. Did you clean the bottom of the throttle body butterfly? Mine has a layer of carbon on it, but I'm a bit wary of touching it in case I break something.

Thanks again
Regards
Pete M

 

Unfortunately while 2 of the supercharger bolts are up front, the third is straight back under the intake elbow. You could try to reach it with a small ratchet, but I couldn't do it. What I've see on some of the S-Type R forum writeups is guys talk about 'slotting' the bracket on the supercharger so that if they ever have to take the supercharger off again they can slide out the supercharger out without taking out the bottom bolt (and can leave on the intake elbow).

Now, when I took mind off the first time what I didn't know was that a prior owner *had left that bolt out* and I could have just lifted out the whole unit with the intake elbow on. I replaced the bolt and found that supercharger removal the second time -- when you know where everything is -- takes about half the time of the first go around.

As for the gasket, it's a super meaty gasket, it's really thick, and I think you could get away with reusing it as long as it's still pliable.

 

Pete, great progress! Can you do me a favor and post a picture of your engine bay when you have it torn down as far as you need to go? Thanks!

 

Hi all,
Work on the Jag has taken a bit of a back seat as other things have taken priority. I have removed the throttle body and I note that the underside of the butterfly is coated with carbon. I have been careful not to touch this, but is there any need to clean it? If so, what is the best method?
Thanks for all the great advice, I'm nearly there!
Pete M


Underside with carbon

Topside, looks ok

 

I'm not sure. I would clean it .
But you better not get grease on your wife's tablecloth.

 

I cleaned mine, with aerosol carb cleaner, and afterwards read that doing so may damage factory coating. Similar caution about disturbing throttle plate in service manual. With typical ignorance, I committed both sins, but car seems fine...

 

My guess is that the "factory coating" was there to stop what you see in plain sight.

Since it did not ...............

Oh and btw the charge coolers will look even worse and will be severely blocked.