Specs: 1999 Jaguar XK8 70,000 miles

Just took apart my main intake hose (the large hose that runs from the airfilter box to the throttle body).

I looked inside the hose and saw an oil/gas residue in the tube (see figure C and D). It looks like a smaller hose ("Breather hose?") is connecting the intake hose to the engine, and this is where the oil/gas is entering. There is a pool of the liquid at the connection point on the engine (see figure A and B).

Questions:
(1) Is the liquid in figure A and B pooling at the connection point "normal"?
(2) Is the spraying of that liquid (figure C and D) into the intake normal?
(3) If these are not normal items, what is wrong with the car, and how to fix it?


Thank you in advance for your help!

 

Yes, those are normal. You mentioned "throttle body." This is the fuel return for your fuel injected engine. Basically, here's what happens:

unburnt fuel goes into the air hose and returns to the intake to get burnt the next time around via what you have called the "breather tube." An over abundance of it would cause your car to flood out, so it seems normal to me.

 

Thanks for your help! I'll clean it all up and put it back in place.

 

I hate to bring up the dreaded word 'Nikasil' but that is a lot more oil than my car puts out the breather tube.

Here is a link to an informative thread on the subject.

https://www.jaguarforums.com/forum/s...ead.php?t=3303

If the car is running well don't worry about it. Drive and enjoy.

Excellent pictures to augment your question.

 

Looks like, Crankcase breather to me. part of your emissions control system, normal to find some deposits here.

Although if excessive you could be looking at worn valve guides, and I stress excessive.

To me your pics look normal. You may also find more deposits in Winter due to lower ambient temperatures especially if coupled with short journeys.

In the old days the breather pipe would just be routed to somewhere under the car and the excess gases would go straight to the atmosphere. Nowadays they are rerouted back into the combustion circuit to be burnt in the engine.

Give it a clean and reconnect everything. make sure your connections are good.

You can get an idea of some of what is going through this system by carefully removing the oil filler cap with the engine running.

Have a rag handy and don't run it too long without the cap. You may very well notice a difference in the running of the engine due to loss of crankcase pressure.

Replace cap.

It might smell as thought there is fuel in the vapour but in reality there is hardly any.

This basic system is pretty much the same for any modern engine.

Just noticed you mention 'spraying' as in 'garden hose' or 'atomiser' type from a perfume bottle.

'Garden hose' not good.

 

Very nice pictures to explain! Though it looks like I'm late to the aprty and you have already been taken care of.

This is somewhat normal, some people install catch cans to collect the residue and keep it out of the intake. Do some research into the PCV (positive case ventilation) system and you will learn about blowby causing crank case pressure and in the old days it would shoot the dipstick out. here's a quic wiki search http://en.wikipedia.org/wiki/PCV_valve

 

What kind of engine oil are you using?

 

Penzoil Synthetic... the oil-change place said it was the best. What oil do you recommend?