This may set off a bit of criticism...Perform a hard-reset of the ECU (remove both battery terminals and touch them together for 30 seconds then replace) Then drive her in "Normal" trans. mode for 300 miles then hard in "Sport" mode thereafter. This helped me and thus congered me into thinking the computer programs, sensors, etc. can be periodically upset and remedied by a hard re-set of the ECU.

 

Most (even cheap) OBD tools can tell you which OBD monitors have & haven't completed (aka set), which can help point to the problem area. Also, you often can't get codes unless they do set.

 

Well it's the one that turns the super charger?? You will need to open the hood of your car and look. You can only get so far talking on the internet!!
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LOL! You sounded just like my mother.

 

Thank you for that... Having never owned a Jaguar, nor a supercharged car, I am not confident even where the supercharger is. It was an honest question, but apparently one not welcome here. I will do my own research to find this information.

 

jag03str, you will find on the left hand side of the engine midway down, a large nut is available to place a breaker bar of the same size. Apply pressure to the left and you will realize that that the tension on the main drive belt has relaxed. At this juncture draw=off the main s/c drive belt. Start engine and listen carefullly.

 

Anytime I purchase a vehicle, I take "reading" material meaning owners manual to the library and read it from cover to cover a couple of times.

I understand clubraith1 response!

no offense, clubraith1 is a well respected member here........tread lightly our new friend

 

I meant no disrespect; I am just not as familiar with this car as my previous 3 series yet and am concerned that I may have more serious issues with the car and the only garage in town that works on Jaguar has decided it is not a routine issue, so they are not interested. I can take it there to have any work done, but they are not interested in diagnosing the issue, which is getting worse everyday. I have constant loss of power with any amount of moderate acceleration along with a knocking noise that only exists between 1500 and 3500 RPM and am very frustrated. I appreciate all of the help on the forums as it seems to be my only place to get help...

 

Have a look for JTIS or workshop manual on here or ebay and all will be much clearer

I believe you have a really experienced jag tech probably within reach - send a PM to xjrguy, he'll fix it!

 

Honestly ... you sound like you could use so hands-on help from a buddy or a mechanic. It will make you a lot more confident about what's going on. If you're super busy then you're going to have to pay for the help.

 

can you post a sound clip of the knocking noise please?

 

I agree that you should find someone to help you, and as for the garage that doesn't want to do the diagnosis but is willing to do the work, they wouldn't be high on my list of places top take my car even if I did have to travel further afield to find some one else.

Here's a pic showing the supercharger in gold.

 

I ordered a JTIS manual on eBay last night and will attempt to remove the super charger belt later today. I will attempt to record the knocking noise, but it is very difficult to here unless you have the window down, so I assume the wind will kill the noise on the recording, but I will try anyway just in case. xjrguy is 3 hours from me in Indy, so I will definitely look him up! Thanks!

 

Does anything need to be removed in order to see this? Do I remove the whole belt once this is accomplished? I don't seem to have much room to get to anything.

 

I also noticed that the ram air intake (I am assuming this is what it is) that has the sticker cautioning about rotating objects at the front of the engine bay has a tube that points down, but is not attached to anything below, it just opens to the bottom of the engine bay. Is this normal?

 

Well, that's the first step in getting to the bottom of your issue. No, the induction system should not be in that state. That means part of your airbox is missing, and you are most likely running on hot air from the engine compartment instead of the cool air from in front of the car. Bad news, that just adds heat to an intake system that CAN'T be cooled enough as it is.

The next thing we need to know is, what is the engine temp at the time you experience the noise and power loss. If you only have a code reader, that means we'll probably have to leave that for a possible trip here to Indy.

After that, let's look into the intercooler coolant pump. That is what circulates coolant through your charge air coolers on either side of the supercharger. That pump is located to the right [passenger] side of the radiator and slightly in front. It should run ANY time the ignition is on. It is powered through fuse F36 [15 amp] in the front fuse/relay box behind the RH headlamp. If it does not run, more bad news; that means the charge air is running at the full temp of compression by the supercharger. That will usually cause terrible spark knock and a host of other possibly harmful things. It could explain the falling on it's face when accelerating.

That car has a pretty light history with Jaguar for it's first 50,000 miles, and I know there is a software update that was put out several years ago to address a spark knock condition in the early STR's. I can find no evidence it has ever been done to your car. Whatever the case, we should at some point take care of that.

So there's a little for you to go on to start with. For now, I'd forget about the supercharger itself and it's belt. The above is more important to investigate first. You look into what you can; for what you can't, we can work on scheduling a trip to Indianapolis.

Good luck! I'll be standing by........

 

The previous owner installed a cold air intake, so I assume that is the reason that intake leads to nothing...Any ideas on where to get a factory air box kit? I have a better OBD II kit on the way that will be here today and will check the engine temp, however, it happens with a cold engine as well. It doesn't seem to be biased toward heat. I will also check the intercooler coolant pump today and will post my observations. I had the software updated just recently to the newest version, but it was not listed on the history as it was not done at a dealer. I will update this afternoon. Thank you again for your help!

 

Er... the factory intake IS a cold air intake. The usual add-on is a HOT air intake, as it gets air from the engine bay instead of the outside as per the factory one. (So the "improved" is actually worse.)

You might find a wrecker with the STR factory stuff (or ebay).

 

Again, that airbox should be your first step. I would try to find a used one, just be sure it is from a supercharged car. It will have the air valve and solenoid to accommodate high air flows better, the non-supers don't have that.

As far as the ECM calibration, maybe they got the right version, maybe they didn't. We don't always know where the aftermarket guys get their cal files from. We can interrogate and find out.

I'll be interested to hear what the status of your intercooler and pump is.

Hey, John, [JagV8]........ you set a pretty high bar, mate!! I'll try to live up, thanks for the plug!

Cheers,

 

hehe - you're welcome

BTW, even an elm327 can read out and report the CALID etc for both PCM & TCM.