Thanks for the reply. O2 sensors could be a possibility, but would faulty O2 sensors account for the amount of oil being pulled? We are talking quite a lot of oil. I was thinking maybe an intake vacuum leak somewhere. And when I say thinking, I mean totally guessing because, frankly, I'm lost at sea here. Just reading a lot of posts and learning as I go.

 

Un burnt fuel mixed with oil vapor can look like oil.

 

You don't have codes John?

 

you should get DTC codes

 

I understand, but I can literally see the oil measurement go down when checking the dipstick after running it for a short while. No oil leaks underneath car... but it's going somewhere.

 

Sean, I think you are asking me (Tracy)... yes, 0171 and 0174. Have been trying to get to the bottom of that, and it was suggested to me to start with the PCV valve, as there was a smallish amount of oil in it. Replace it... and That's when all hell broke loose.

 

Still have the old one? And did you check for a collapsed hose?

 

Yes, I put that one back on, but same results. Put the new one back on from the Jag dealer, as that seemed to be working the best... still oil in it, though. Tomorrow we are going to do another vacuum test, this time by blowing air in each cylinder and seeing (hopefully) where we are getting a vacuum leak.

 

Ok then oil it is.

 

jakra, you were correct. While I did lose some oil when I installed the new PCV, the problem was all 4 O2 sensors. I thought for sure what was burning through the exhaust was oil, but it was fuel. Put some new O2 sensors (which, by the way, were VERY easy to install... took less than an hour to remove all 4 and re-install the new ones, front and back), started it up, and while still smoking, eventually it diminished rapidly, took it on the freeway here, and burned it to just about nothing.

Now, I still have the 0174 and 0174 lean codes, but at least it is running. Very rough at start-up and idle for at least 10-15 minutes. The hard idle is strange... if I pull up to a stoplight, it lurches back and forward, rather than a standstill rough idle, if that makes any sense... I have to put it in park until the light changes, it lurches so much. Have no idea what this could be, or how it relates to the lean codes. Trying to get to the bottom of that now. Have a new MAF, no change. Checked all the hoses and clamps (at least the ones I could see). But I noticed that the hose going into the airbox was not the correct hose, according to Jaguar diagrams for my vehicle, so I ordered a new one and will see if that makes a difference.

 

I did not get any codes when this happened Sean. As soon as I removed the mini cats and positioned the O2 sensors as normal everything was fine with the 200 cel cats.

 

This really sounds like some form of leak in the intake system. When you say "not the correct hose" what hose are you referring to?

 

Well, I think it's called the the air filter intake duct pipe (has a rectangular opening). Mine definitely looks different than the original. I don't know if this would cause the poor idle I am experiencing, but a cheap enough part to replace. Part will arrive on Thursday.

So... a leak in the intake system. After all I have read regarding my symptoms and lean codes, and not being able to pinpoint any obvious leaks, should I be looking at a possible intake manifold leak?

 

It is a possibility. See what happens after replacing the intake pipe.

Your symptoms when stationary at lights would seem to indicate more than just a slight leak. Have a look thru the below thread:

https://www.jaguarforums.com/forum/x...h-idle-182699/

 

I'll see what happens after I put that hose on, but thinking, like you indicated, that I'm looking at more than just a slight leak.

Thanks for link. A question about dirty/bad injectors related to rough idle: I'm thinking that a quick clean with an injector cleaner poured through the tank? I can see how bad injectors could cause rough engine, but not sure how that would throw the 0171 and 0174 codes? Seriously appreciate your help, and others... I know so little about working on cars, though I have learned more in the past 9 months of owning my Jaguar than in all years previously combined -- out of necessity, I suppose.

 

A good injector cleaner would not hurt at all. I use one every other tank fill.

Good quality gas "should" not require it as many have said but.............

I am retired and my Jag is my "toy" according to my wife. I enjoy working on cars and always have so long as I am not under pressure to get something fixed quickly.

 

UPDATE: Still getting 0171 and 0174 lean codes... no new news there. The good news is it is not smoking... at all. So there's that. Still trying to get to the bottom of that of the lean codes. Intermittent rough driving, with restricted performance. Drove it this morning, and it was driving very rough. Checked for new codes... the bad news:

0300 - random misfire detected
0301- Cylinder 1 misfire detected
0302- Cylinder 2 misfire detected
0304- Cylinder 4 misfire detected
0305- Cylinder 5 misfire detected
0306- Cylinder 6 misfire detected
0307- Cylinder 7 misfire detected
0308- Cylinder 8 misfire detected
1316- Misfire rate exceeds emissions
0206- Injector circuit / open - cylinder 6

LOL! That's it. Multiple misfires with 0171 and 0174. Intake manifold leak? Leaks around the injectors? Thanks in advance for any input!

 

Are you still losing any coolant? You mentioned that earlier.

A .I would swap the coil packs between Cylinder 1 and say 2 and see if the fault transfers. I assume the spark plug is good but might as well check that anyway in cylinder 1.

B. Check cylinder 6 plug to see if it is wet with fuel. It might show or the plug could be extra black with soot/carbon.

Do A first before B is my suggestion.

 

Thanks, John. No coolant leak that I can see... looks topped off at max. I will look into swapping the coil packs as mentioned. Seems odd that all but cylinder 3 are misfiring.
The jaguar manual that we have been referring to suggested that if the car is having multiple misfires coupled with 0171 and 0174 that it could likely be an intake manifold leak or leaks around the injectors, so will look into those as well.

 

Ok misread your post on nearly all cylinders misfiring! I read that as only cylinder 1. So forget what I said about swapping no point in that.

It certainly looks like a leak but also something to do with the cylinder 6 open circuit on the injector. Looks like two separate faults.