My XJ has a small oil leak I have noticed on the garage floor. I am a novice with DIY car repair and would like to try to diagnose this myself. I know the first step would be to remove the shielding. Should I keep the car on a level surface, or put it in 4 jack stands? Any tips of what to look for in a 5.0 V8 SC? Engine monitor oil level is fine.

 

If you decide to put your X351 on jack stands, refer to the Workshop Manual as to the correct way to raise the vehicle so the body is not twisted. If the car is being lifted onto jack stands, it must be raised equally with two floor jacks, one on each side of the vehicle to prevent damage.

 

Whereabouts is the leak on the garage floor? Meaning what side of the car, front or back, etc.?

 

Front, middle, just behind the front axle. Very small but it's there. And I know these don't get any better. The shield is on (I do oil changes via extractor). I don't have 2 Jacks so I'll have to figure that one out.

 

My guess is the vacuum pump "O" ring seal is leaking. There are several threads that found this as have I. Some replace the vacuum pump and some the seal.

 

Yes check the vacuum pump on the front of the engine.
It could be a very simple and cheap fix.

The dealer will for sure replace the entire assembly at a high cost but all the DIY threads have just replaced the O-ring. In fact what I have seen is it's usually loose bolts which cause the leak and NOT a bad O-ring.
But with the cost of everything please put a new O-ring in!
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I would imagine the leak could be significant if its puddling enough to drip past the shield. I would get it checked out ASAP.

 

My leak in front was from the mechanical vacuum pump. Located on the lower front of the engine. I had to raise the vehicle and remove the drip pan to get to it. Very easy to get to underneath. At 110,000 miles I decided to replace the pump. Two bolts hold it on. When you remove the pump, you will lose oil, replace what you lose. I was having a slight hard downshift from 2nd to 1st gear when coming to a slow stop. I no longer have that problem.

*** side note, the new pump needed slightly longer bolts. Maybe 3/8 inch longer. Luckily we had some available.

 

Not a bad idea at all!

What was the cost of the vacuum pump?
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I got my pump for $381.44.

The two longer screws you need are part C2Z30121.

 

So after removing about 26 bolts and getting past the shields, this is what I find. Looks like the vacuum pump, but it's hard to tell as there's oil kind of all over the place

 

I'll be ordering a new O ring and hopefully that solves the leak. At 60k miles I think the pump should still have life left

 

Yep you got it!
Nice picture too.

Were the bolts loose?
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I was able to tighten them, but not too much. I know their specs are 12nm as per the service manual, but my torque wrench won't fit in there. So I just tested and I'll monitor for leaks, and order the O ring in the meantime.

 

Hello I have the same issue replaced the o ring now it’s leaking worse new vacuum pump maybe?

 

I would inspect the O-ring again and maybe just replace it anyway.
Your new pump won't fit any different from your old one. And it's EXPENSIVE!

Did you replace the O-ring?
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I replaced the o ring then that’s when it got worse

 

I don't know then? Bolts tight and new O-ring.
That's all there is.

Maybe leaking from somewhere else?
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They started using a longer bolt on the vacuum pump in the last few years. I know my tech switched mine over to the longer one when my pump was done.

EDIT: I see I already posted this info and the part number above. Sorry.



If the manual says 12nm force, then okay. But that sounds way to low (~8.9 ft-lbs).

Perhaps reclean the o-ring, rub some clean oil on it, and then bolt it on again to specification.

 

Hello everyone How do I take the grey and red elbow off?