So I had a restricted performance light come on last week. That was the only time I've ever had any engine performance related issue with this car. I restarted the car and it went away. I was going to the dealer anyway later that week for some small stuff so they took a look at it.

I get a call yesterday and they told me that the cause was carbon build up on the injectors. They said it has been causing a misfire for quite some time (I've never noticed any hesitation or any engine lights). The dealer says the issue is due to the added ethanol in our gas and that they don't cover injector cleaning under warranty. They want to charge me $300 to clean the injectors. Why isn't this covered under warranty? Audi has a carbon issue too with their FSI motors and if it happens under warranty the dealers have a TSB about how to clean the motors. Mine is a 4.2L and since this 4.2L isn't exactly a new motor I'm sure it isn't direct injected. If it isn't direct injected how can there be carbon build up on the injectors? Second why is the clean only $300? Services for cleaning injectors are normally about $80 per injector plus labor. If they are trying to charge me $300 to dump a bottle of cleaner in the car I'm going to be really pissed.

My service guy said he was going to contact Jaguar to see if they will step up and cover it. I work on motors all the time so there is no way I'm paying the dealer for an injector clean that I'm sure I can do myself. I obviously don't want to void the warranty and I'm worried they will charge me for the diagnostic now that they say it isn't a warranty item.

Anyone hear of any similar issues on another 4.2L XF? I can see it happening on the 5.0L easily since it's direct injected. If the dealer is correct it should be happening on every XF and I've yet to hear of it happening. I only have 33k on the car.

Thoughts?

 

This is a big problem for DI engines. The detergents don't flow over nice clean injector tips in the intake ports, they pass through the tips right where the flames occur and the fuel ignites almost immediately. Gasoline manufacturers can't do much about the physics of this. Diesel cleans and lubricate, gasoline strips any lubricant away and does no cleaning unaided by detergents. Jaguar has to pay for this. It is the design and implementation of gasoline DI that is the cause of this issue. Intake valves are also subject to carbon fouling as no fuel passes over them anymore.

 

Take a little knowledge and give it to an advisor thats is trying to explain something to a customer that for most instances your speaking greek to. Just equals wrong info and statements. I cannot count how many times Ive explained things to an advisor only to listen to them on the phone explaining to a customer and i look at them and say "that is not what i told you!" they hang up and say it doesnt matter they dont understand anyway. "but youre giving incorrect info and it matters to me, because then if an issue comes up im the one that gets the blame not you!"
yes the di engines do have issue and a 4.2 does not have a carbon buildup issue. But they just like any other injected car does have issue with normal deposits. My friends over at Fuel Injector Cleaning Service : Injector Cleaning Service : Injector Cleaning : Clogged injectors : Injector Flow Testing : InjectorRX.com charge only $18 per injector for testing before and after for flow, cleaning, reoringing and screens. And normally do a 1 day turnaround if not same day.
Jaguar recommends bg-44 in tank up to 2x''s per15k and yes youll pay for it. Its considered maintenace just like and oil change or airfilters etc.. You can get over the counter too

 

Thanks for the info Brutal. That is pretty much what I was thinking. Carbon buildup on my injectors doesn't make any sense. I have the 4.2L and it isn't direct injected. If the injectors are dirty for some odd reason then I guess they are dirty and I'll have to get them cleaned. I'd still prefer to do it on my own if possible (pull them and have a shop with the proper equipment clean them).

To me it seems odd that a car with 33k on it has issues when I've never really heard of injector issues with a car anywhere near that low of mileage. I wonder if the techs even looked at the motor. They could have driven the car or pulled the codes and immediately said it needs a carbon clean because they thought it was a DI motor.

 

Im sure the tech knows the differance, just not the advisor when talking about issues with you. You understand, but most do not as I referred to earlier. dont take it that its not a gas issue either. I have tested gas before and found several times more than 10% ethanol in a sample. not to mention what crap comes out of the service station tanks. The pumps are supposed to have filter inline. but i know when I was a teen in the 70's working at a gas station, the owner wouldnt put in filters. they were to expensive and im sure theres poor maintence at that point now and differant places too. the BG 44 additive is refferred to by jaguar for random misfires and cold start and idle roughness. of which you only seem to have random misses. So its a cheap start. you wouldnt want to pull the injectors on the 5.0 anyway since it takes a injector puller, a teflon oring installer and resizer for installation to get them out and back in.

 

Jaguar came back and said they'd cover half the service to "help me out" so they want to charge me $150 instead of $300 to flush the injectors out. They said they do this when the injectors in the car. I wanted to take it on myself but I was a bit worried about how that would affect the warranty. I told them to do it. At least this way if that isn't the real problem they will have to keep digging into it. If it fixes it then fine I'll look into running injector cleaner every so often. The service adviser said this is a major issue with the 4.2L motors. They have them in here all the time for the same reason (dirty injectors) and said it's because of Minnesota's fuel (too much ethanol). I don't know if I necessarily believe ethanol as the cause but if the flush fixes the issue I'll be happy.

 

Injector cleaner doesn't help. The issue with DI eingines is carbon build up on the valves themselves. In non-DI engines the fuel spray "washes" the valves as it enters the cylinder. In DI engines this doesn't happen as the fuel is injected directly into the cylinder.

Lexus gets around this by having 2 sets of injectors per cylinder on their V6. Non-DI injection is used at low RPMs and then at high RPMs the engine swuitches over to DI. That way the valves still get "washed" so carbon build up isn't an issue.

Here are some images of valves on Audi/VW's DI engine show the carbon build up on the intake valves.

 

I have a 4.2L which is not direct injected so there is no carbon build up. The service guy said he "mis spoke" just as Brutal was figuring. The injectors are dirty or clogged from what they said is a high ethanol content in MN fuels.

I know all about the Audi carbon issues. I owned a 06 S4 and read all about the RS4 carbon issues on the forums. It's ridiculously bad in the RS4.

 

Interesting. What's considered "high content"?

 

LOL....DO I KNOW SERVICE ADVISORS AND JAGS OR WHAT
I HAVE TESTED FUEL AND FOUND SOME SAMPLES 13-20%. I HEAR THROUGH THE GRAPEVINE THAT MIDWEST CORN BELT AREA ARE WORSE, MAYBE NOT IN JUST CONTENT%, BUT NUMBER FOUND HIGHER THAN 10%. ON THE PUMPS IT SAYS "MAY CONTAIN UP TO 10% ETHANOL" WE RUN INTO MORE OF AN ISSUE WITH HIGHER THAN NORMAL ON COLD START PERFORMANCE AND MISFIRES. ITS NOT WIDE SPREAD THAT IVE SEEN OR TESTED, BUT I KNOW THE GUYS THAT DO INJECTOR CLEANING ALSO SAY ITS AN ISSUE. BUT MORE SO IN THE MARINE INDUSTRY WERE ALOT OF FUEL TANKS ARE FIBERGLASS. ADDITIVE AS WELL AS ETHANOL SORTA EATS THE INSIDE OF THE TANKS AND PLUG OR FOUL INJECTORS. THIS IS WHY ALOT OF FUEL TANKS AND FUEL LINES ARE A CROSSLINKS PLASTIC THAT FOR THE MOST PART IS IMPERVIOUS TO FUELS AND ADDITIVE. BUT THAT DOESNT MEEN THAT THE FUEL STORAGE TANKS ARE. MATTER OF FACT EVERYTIME I SEE TANKS GOING IN OR OUT OF A SERVICE STATION THEY LOOK LIKE FIBRGLASS TO ME.
I JUST TOOK THE FUEL LINES OFF MY RACE CAR AND THE FITTING ARE CORRODED INSIDE AND THE RUBBER IS DRY ROTTED AFTER 7 YRS. I RUN SUPERUNLEADED GAS SINCE I BUILT THE 580 CID ENGINE WITH 9TO1 COMPRESSION AND DONT RUN RACE GAS UNLESS IM SPRAYING NITROUS. SO IVE BEEN THINKING ABOUT CHANGING OVER THE ENTIRE FUEL SYSTEM TO THE SAME TYPE LINES IN LATE MODEL CARS. BUT THE COST IS 3-4 TIMES THAT OF BRAIDED LINE AND ALUMINUM FITTINGS SO I LL JUST STAY WHERE IM AT FOR NOW. BESIDES IT CARB'D NOT INJECTED(YET )
I WOULD SAY LET THEM DO IT. BUT WHAT ARE THEY USING FOR ONBOARD? I ONLY RECOMMEND AND USE BG PRODUCTS CAUSE I KNOW THEY WORK. MOC SUCKS AND ITS A BIG PLAYER BUT ON BEFORE AND AFTER TESTS IVE DONE IT DOES LITTLE GOOD AND BG DOES AN EXCELLANT JOB.

 

Update:

When I went to pick the car up the dealer said they would cover the other half of the flush so I didn't have to pay anything. Yay!

The car has been great now for about two weeks. Yesterday on the way home from work it popped the restricted performance light again. Surprise! The flush doesn't appear to have done anything. The car appears to only do it when cold, shifts very hard, car in dynamic mode, and 50% + throttle. I'm going to run the codes to see what pops up before bringing it in. A restart cleared the message.