Hi, my 2007 4.2 XKR has recently been sufferring from an engine malfunction warning light, which has been appearing and disappearing randomly for a couple of weeks now.

My garage suggested it is probably one of the lambda sensors, but unfortunately after hooking up to his machine he has identified that the super charger is loosing air.

He has suggested that he replaces all the seals, but to do this is a 6 hour job, so it isn't cheap.

The car has done 122,000 miles in 10 years and this is yet another of the many issues I seem to be encountering these days.

I'm not very machanically minded, but would be interested to understand a little more about how the Super Charger leaks air and why it's such a big job to resolve it.

Any info would be appreciated.

 

If you post the code(s) that are generated (use an OBD code reader), you may get a better response from those that have had the same problem. Or you could search the forum for the code(s) to see how it was addressed before.

 

Sorry, I don't have the ability to read the codes and I don't feel I can ask the guy at the garage. I appreciate I haven't given that much information, I'm just re-iterating what I was told needed to be done to fix the issue.

 

Around here in the US, local car parts stores like Autozone will read your codes for free. Hopefully something like that exists in England. At least if you have the codes, you will have a better idea of the exact issue.

 

I'm not aware you can get anything like that done for free in England!

The dealers used to check things for free while it was under its 3 year warranty as obviously they wanted the work and could claim for faults from the manufacturer. As soon as the 3 year warranty was up, they started charging for everything, even checking the codes. At this point I started using alternative garages, like the one I use now, who are prepared to check the codes without charge, but I suspect this is only because he knows me and my car as he regularly services it.

 

Buy this:
It will read your Engine Codes. You'll be able to erase them also.
PLUS, you can get literally hundreds of real-time parameters like Engine Temp, battery voltage, heck, even mundane stuff like fuel trims and other stuff you and I probably don't even understand.
AND.... it will also do performance calculations such as 0-60-0-100, 60-100 and a WHOLE LOT more.

 

Does that work with an I-phone? Or do you need a computer with Bluetooth?

 

I'm curious how he is diagnosing the problem. To me, a leaking seal at the blower would be simplest troubleshot with a can of ether sprayed around the joints and below the inter coolers.

If he is using a scan tool (machine) to read the engine computer (ECU) check engine light (CEL) codes then we really need those codes to help determine which direction to troubleshoot. The reasoning why is because (and remember this) all the ECU is doing is reading inputs from sensors to determine what's going on and setting outputs to valves (injectors, throttle, cam timing etc.) get the inputs to go to the value it wants them at. Really, honestly ***** simple at this level. Looks at inputs, sets outputs to change inputs. CEL's come from not being able to get the inputs where the ECU wants them. Newer engines with the OBDii processing are intuitive enough that they can help diagnose a problem if the inputs are honest so it's always important to verify the data before changing parts based purely off of codes.

Per the repair, there's a ton of stuff that needs pulled off the top of the engine as well as drain the engine and inter cooler coolant. The stuff back by the throttle body is difficult to get to and if your guys is quoting 6 hours then he is moving along pretty quickly.

Post up the codes and try to get an understanding of your mechanics troubleshooting. Should be educational to us all.

 

Oh, you just have to have an iphone for some weird reason. That's sad.
You can get a WiFi version of the OBD2 readers that work, sorta. OR, be normal and get a second-hand Android device for a couple bucks and use it exclusively with your OBD.
Or be even COOLER and trash the iphoney and get a decent phone.
Regardless of which way, the OBD2 systems work very well.

 

I do already have a OBDII reader that reads and clears codes. Doesn't do much else, though. I figured for 6 bucks I could do all those other cool things, that would be excellent. Just not sure the best way to get the readout. Probably not going to go get another phone, or computer though.

 

As you've an iPhone you get to pay more for the WiFi tool (and get somewhat crappier software) but the elm327 is better than what you have for not much money.

 

An old (but still very able) Android phone or tablet can be had for $20 or thereabouts. It would not need to be activated to use (other than a free Google account), and it would work perfectly well as a dedicated accessory.

 

Just thought I'd give an update to my XKR issues that have now been ongoing for a couple of months.

Initially, the garage thought air was leaking from the super charger so was going to replace the seals, however, he ended up replacing one of the four lambda sensors as the error codes showed it had failed.

Got the car back and the following day the engine malfunction indicator came on again. Back to the garage and error codes showed a different lambda sensor (on the same side) had failed. This was replaced, so both pre and post CAT sensors have been replaced.

Got the car back from the garage and on the first drive out the engine malfunction indicator came on!

Also noticed that after refuelling the car runs like a dog but is usually okay the next time it is used (the following day). It is thought that an issue with the petrol tank not being pressurised might be the issue, but it may also be as a result of the engine malfunction indicator. Simply removing and replacing the petrol cap replicates the issue, so not a "bad" fuel problem.

Back to the garage, this time to keep for a few days. Replaced the CAT with a "dummy" CAT, but as expected, the error codes did NOT disappear, suggesting it wasn't a CAT issue. Eventually decided the ECU was to blame after testing a new cable, so it was sent of for examination and a fault was found and repaired. Re-tested by the garage and everything appeared to be okay.

Picked up the car and within 10 minutes driving the engine malfunction indicator was back on again!

So, it's hopefully going back to the garage mid week for more checks.

Getting really, really tired of this issue.

 

You should have

1) changed garages several trips ago. Your guy is just guessing

2) bought the recommended tool and posted the codes here for some real troubleshooting assistance.

 

Yep, fools and their money... Horse to water...

 

Is the garage's diagnosis really bad and is he just guessing? Assume he is getting P013X code(s), indicating a bad 02 sensor. Ordinarily an easy fix - change the sensor and you are done. I have done that a dozen times with no bad results.

But that did not fix it in this case. IF the SC is leaking pressurized air, then the MAFM will measure X CFM going into the SC. But Y CFM is leaking out. So X-Y CFM is actually going into the engine. The ECU is trying to deliver fuel to be burned with X CFM of air, but there is less air available. So the O2 sensors see a rich mixture (low O2 content) and the ECU tries to compensate. But it can't compensate enough to get the O2 sensors in range and it has to set an error.

(If the SC is leaking on the inlet side the mixture will be lean and the O2 sensors will report a high O2 content for which the ECU cannot compensate.)

I am not sure that spraying ether around the base of the SC will tell you anything, especially if it is idling OK. Probably is with a slightly rich mixture. Isn't it pressurized there so air would leak out, not ether leak in as on a NA car?

Really need to see the error codes. If there are P013X codes after replacing O2 sensors maybe a leak in the air delivery circuit is not a bad diagnosis. (Hope he changed the correct sensors for the bank with the fault.) Without knowing the actual codes I am not sure why changing the CAT would be indicated.

 

Could go old-school to troubleshoot.... get a stethoscope and go poking around everywhere listening for an air leak. OR...... soapy water, and watch for bubbles!

 

Take it to the main dealer, stop your mechanic throwing parts at it and guessing wildly with your money. If you had done this from the start it would be fixed by now,it would have been cheaper and you would have a car that you can drive

 

Mufc, if only I had your faith in main dealers, I would still be using them!

The guy who looks after my car is an ex Jaguar main dealer mechanic who setup when the local main dealer decided to shutdown a number of branches, including the one nearest to where I live and from where I purchased my car.

I trust this guy more than I do a main dealer and lets face it they are only as good as their mechanics!

I can also say with certainty that ANY work that may have been done at a main dealer would not be cheaper! They charge £80 just to hook up to their diagnostic machine!

 

Dang, I was hoping for an update on how it's running.