Hello,

So I decided to take some friends to Montreal in my newly acquired 2005 VDP. Trip went well, but I did notice after about 3 hours of driving at Hwy speeds (130 KM/H) a burning smell come in through the air vents. I opened the windows for a minute, then closed them and no more smell inside the cabin. When I pulled off for gas I did notice the burning smell around the front end of the car. No warning lights and no fluctuations from ant gauges inside. This did not appear to be a sweet coolant smell, but rather a more hot metal/oil smell.

I drove another two hours and no smell in the vents, but when I arrived in Montreal and sniffed around the grille I noticed it from the driver's side half of the grille (hood closed) but not as strong as before.

Driving back I didn't notice it, and driving short distances around town I don't notice it - after a 15 minute drive I check the grille area for smells and don't smell anything, but when I drive it for more than an hour at speed I get the burning smell. Trying to figure out what it is.

My tire shop says the tires and brakes are good and no prob with wheel bearings. The oil change place says the oil pan and transmission pan are not leaking. Coolant level is where it is supposed to be. Driving the car around the block doesn't replicate the burning smell - it has to go for hours on the hwy to start doing it. I put paper under the car but no leaks on it other than clear water from the center area of the underside (a/c condensation prob?) after the car is first turned off. Maybe a 1/4 cup water puddle. I had an evap smoke test and no leaks to the fuel or exhaust systems. Speaking of smoke, this problem doesn't produce any blue or white smoke - it is odor only when it comes in.

Any ideas?

On another post someone recommended checking for oil leaking from the cam covers. I have not checked for that yet. Not sure what to look for but could ask the garage to look at those.

Another suggestion was the final drive/differential - check for leaks. I haven't changed this fluid, but thought it was good for 160,000 MI so it is not due yet for change. Also, if that was the problem why would the smell come from the engine bay area and the vents at speed?

The firewall insulation along the rear of the engine bay has some mouse damage (hole in it) but doesn't appear to be touching the engine.

Thanks

 

on a 350, there can be oil or fluid leaks that you will not see until you take the plastic undertray off.

On mine I noticed the hot oil smell and it was the steering pump weepng (it does get very hot). The loss can be so small that you don't see the levels dropping. I presume you haven't been topping it up and spilling oil?

Time to get it up on a ramp, I think.

 

So, an update on trying to find why there is an intermittent burning oil type smell after 3 hours of running the car on a highway at cruising speed (130 km/h)

The gaskets seals are dry, so it isn't a leak there. The power steering looks dry too from looking at it under the car.

Not having a hoist, I am looking on my back with a flashlight under the car.

What I did notice today is a couple of thin pipes that were coated in oil. Not the golden/tawny oil found in my engine, but a pitch black oil. These pipes were toward the rear of the car, on the passenger side - under the car about where the centre of the rear passenger side door is. When I touch the pipes with my hand a liquid black oil residue is on my fingers. I wiped a bit off on a white cloth to photograph the colour.

So I'm wondering where this black oil is coming from (no leak spots on my garage floor, so it seems to be a weeping leak I would guess as the flow can't be too great or it would leave black drips on the floor.

Any suggestions as to where this oil is coming from? The under car shielding is preventing me from following the pipes, though there is no other part of the bottom of the car that has any wet oil on it that I can see, including the engine both above and below (front shield removed). Engine oil pan is dry on the bottom, took off the plastic engine cover under the hood and all is clean and dry under there too, no gasket leaks. Could it be the differential case weeping final drive oil? If so, perhaps the burning I smell is the differential slightly overheating due to low fluid level during long trips, and it doesn't heat up on enough on short trips or in rush hour traffic as the car isn't moving forward for long enough.

Interesting mystery...

 

Kinda looks like brake lines, but might be related to your EVAP system since I think you gas tank fill is on that side. Can you follow those hose forward to see where the leak starts from? Look more like a motor oil leak from somewhere but hard to tell when the oil gets that dirty. Try to just find a drop hanging somewhere and lightly touch a paper towel to it to see the color better, don't wipe.

 

I stopped by the gas station service bay while on my way to work as there was no car in the bay. I asked if they would raise the car up on the lift so I could take a look and the mechanic said 'sure'. I bought us both donuts and coffee while he was raising the car. So we stood under it having a look. He agreed the pipes are the brake lines, but he wasn't sure if they were actually leaking. So he sprayed the wet lines with something followed by compressed air. He said if they are leaking, they will be wet tonight to the touch, otherwise they will be dry to the touch due to his cleaning them.

We looked at the differential and when he ran his hand along it there was a faint film of oil on his hand. He said a little sweating from the differential is normal so he probably wouldn't worry about it. He looked under the engine and said no motor oil leaks were visible. though the oil pan was new (still had the Jaguar sticker on it) so if the pan was leaking before, the underside of the car might have oily residue from that as when the pan was replaced whoever did it didn't clean the old oil residue off the areas around the pan. He said go through a car wash with 'bottom blaster' feature on and try to clean off the old oil and then see if there still is an issue somewhere.

He said he doesn't work on Jags as he says they are complex and too many things have to be moved to get at anything, and he joked that people don't expect high labour charges from a gas station like they do from a dealer.

He did say the underside looked it very good condition for a 2005, just put paper under it and see if any drips (I did that already and no drips). I'll see if the brake line is wet tonight again or if his spray has kept it a dry matte finish.

I didn't know the differential was supposed to sweat though. He said I wouldn't smell burning from there even if it was leaking at highway speed as it is at the rear and the wind would carry the smell away from the car. Anyway, his was the only bay I had access to without an appointment on the drive to work. We couldn't follow the lines forward as they go underneath shielding of some sort that would first have to be removed.

 

I would have though that to get this smell, oil, (or something), is getting onto the hot exhaust towards the front of the car. There are two lines from the transmission to the front of the car to take tranny fluid to and from the transmission cooling radiator. The pipes exit on the LH side of the tranny, and would be just above the LH side exhaust, I would think. The pipes are steel, and have no flexibles anywhere.