Trying to find oil leakage XUD9

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CPtje
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Re: Trying to find oil leakage XUD9

Post by CPtje »

Nice, so it is okay to just remove one cylinder head bolt only. Will need to get the right socket wrench first and look up the right figure to fasten it again. Do I need to replace the bolt or can I re-use this one?

Replacing the HG is probably too difficult for me, so let's see if this will help.

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white exec
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Re: Trying to find oil leakage XUD9

Post by white exec »

It's unusual to remove just one cylinder head bolt, but I don't think it will do any harm in this unusual circumstance.
Might be worth checking that it was actually properly tightened, when you get the socket and the torque figure.

If that O-ring in the corner of the HG goes leaky, engine oil under pressure (up to 6 bar) can find its way in various directions. It can leak across the HG and into a nearby waterway (you then get engine oil injected into the coolant), or into the neighbouring cylinder (unusual, because the HG is reinforced around the cylinder bore - causing the engine to burn oil), or leaking across the HG into the ouside world (oil dribbling from the HG and down the side of the engine).

What you seem to have (oil around the head bolt) does seem to be consistent with the O-ring going leaky. Just my best guess.

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myglaren
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Re: Trying to find oil leakage XUD9

Post by myglaren »

white exec wrote:
09 Jun 2020, 13:15
What you seem to have (oil around the head bolt) does seem to be consistent with the O-ring going leaky. Just my best guess.
Is this not a common problem with the XUD or was that another PSA engine?

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white exec
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Re: Trying to find oil leakage XUD9

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It was a common problem with XUD. On BX diesel, a poor header tank arrangement (just a large air gap at the top of the radiator on some models) could lead to air locks and hot-spots in the head, which warped the head and allowed the HG to leak. The oilway captive O-ring (part of the HG) could also bake hard and go leaky. Same thing not unknown on XM 2.5, if cooling system is neglected.

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CPtje
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Re: Trying to find oil leakage XUD9

Post by CPtje »

Okay, all visible oil leakage but one are resolved. Did cost me some effort to get the cam cover leak free, but finally succeeded with all your help.

However, the real problem is not solved. 1ltr of oil is disappearing each 400km. So now, the real question is... is it the engine or the turbo. Is there a simple way to know this for sure. The turbo looks "wet" from the outside.
IMG_20200915_124750.jpg
I cannot say that I have lots of blue smoke, but I can smell burned engine oil sometimes when driving with the windows open.

For instance, is there a way to check if the engine is burning oil by taking of the turbo somehow? Is it possible, would it work to check this way if the engine itself is okay?
Pricewise, a new turbo would be okay if I am sure the engine isn't the problem. However, if the engine would need a complete overhaul, I might be better off with a replacement engine.

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CPtje
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Re: Trying to find oil leakage XUD9

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Extra info: Just took of this piece of hose from between the turbo and the intercooler. I can't remember it to be this wet some years ago. Is this more than just from the fumes? Can this be only because of the turbo or can there be another cause for this? ( and the oil usage of 1ltr on 400km).
IMG_20200919_140106_1.jpg
IMG_20200919_140131.jpg
IMG_20200919_140417.jpg

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white exec
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Re: Trying to find oil leakage XUD9

Post by white exec »

Not unusual for the pipework from turbo to intercooler to be oily, and inside the intercooler too.

With the car parked up and engine properly warmed up, if you boot the accelerator hard, is there any sign of blue smoke from the exhaust? Black smoke would just be down to the extra fuel being injected; white smoke could be glycol coolant getting into one of the cylinders, and burning (unlikely - you would have mentioned that).

As you say, 1 litre in 400km is either a physical leak, or it's getting combusted.
How's the compression? Just wondering about piston ring condition?

Another possible route for heavy oil consumption is worn valve-guide O-rings, which let oil from the valve/cam area get sucked into the cylinders.

moizeau
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Re: Trying to find oil leakage XUD9

Post by moizeau »

Have a friend follow you at night. Headlights show wonderful things. If valve guide seals are that worn I'd expect very sooty heater plugs and a puff on gear changes. Have you looked at the heater plugs, not from a starting issue from a 'spark plug' point of view, are they a nice light grey?
My BX's oil used to get up to the air filter but didn't use much.
Sounds like it's starting to drink it's own oil if there are no obvious leaks externally.

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CPtje
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Re: Trying to find oil leakage XUD9

Post by CPtje »

No white smoke. No oil in coolant.

Some grey/blueish smoke but not that noticeable.

Compression not checked. Need to have this done in a garage.

Anything more I can check for myself? More ideas?

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Re: Trying to find oil leakage XUD9

Post by moizeau »

Whip the glow plugs out and see if any are sooty.

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CPtje
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Re: Trying to find oil leakage XUD9

Post by CPtje »

Took the glow plugs out this morning. They are 3-4 years old. It always starts without a problem. They are not really wet or something. But the left one does not look right. It's from the most right cylinder. Is this sooth or something else?
Or would you define this as all 4 are soothy because they are not white grey at the tip?
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Last edited by CPtje on 21 Sep 2020, 11:46, edited 1 time in total.

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myglaren
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Re: Trying to find oil leakage XUD9

Post by myglaren »

Might be a good thing to test them while they are out.



If they are faulty then Beru replacements are recommended.