More problems! Low oil pressure, ticking & swarf in oil!!!

[JimmySpeed]

After finding out that my misfire on 2002 X5 4.6is was down to a leaking head gasket, and getting that fixed and having the car run perfect for 500 miles or so, a new (or seemingly new) problem has occured;

Today when driving I started hearing a clicking sound coming from the car and started to look for a place to pull over, as I made my way off the dual carriageway the low pressure warning came on. I stopped and the oil was low, towards the bottom of the dip stick. I topped it up - took 2 litres to get to the top of the dip stick - and started it and the sound went away. Drove off and within seconds the sound and the oil pressure warning returned.

Had it towed to my mechanic who checked the oil filter and it has alot of swarf in it. He flushed the oil system and changed the oil and put in new filter (as the filter was clearly blocking the flow of oil due to the swarf). It sounded fine once running again but as soon as I drove up the road the sound came back and the oil pressure warning came back.

It appears that whenever its topped up, all sounds normal and oil pressure seems fine but as soon as the car is driven just a few meters, the pressure cannot be maintained and the oil does not circulate. The noise seems to occur when the pressure drops and oil is not reaching all parts of the engine.

The mechanic is going to strip down the car - sump, oil pump, timing case, rocker covers etc - everything off for full inspection. However I am interested to hear what you guys think may be the problem. And where the swarf has come from...

[X5Sport]

Could be main white metal bearings on the crank, camshaft bearings, big end bearing shells, timing gear/chains, or the oil pump itself has failed.  In any event it sounds expensive.  Is it steel or Ali swarf?

If they had the head(s) off, were they tightened down correctly and checked for warping and skimmed if needed.  Sounds like the engine wasn't re-assembled correctly to me.

Sorry you're not having much luck with this one....

Richard

[IanP]

As I had the same problems, here is my best guess. One or more of the cam chain guides is damaged or broken, this as allowing the cam chains to flap around which is gouging lumps out of the chain casing hence the swarf. The low oil pressure is possibly due to the tensioner coming too far out of its housing. If it was all OK before you had the head work done I would say something was not put together correctly. After you get the work done you MUST remove the sump pan and clean the pump suction filter. You might find this is blocked now which could cause your low oil pressure, if this is the case then you will hear the oil pump howling when  the engine is run.

[JimmySpeed]

Cheers Ian. I was hoping you would chime in.

I'm already expecting to have to do the timing chain kit and oil pump anyway. If the damage is localised to these areas I won't be happy but I won't be shocked either...

[IanP]

I think to change the oil pump you will need to remove the front driveshafts and engine cradle to get the sump off. I changed my oil pump due to the amount of swarf that had been flying around, a lot had got into the oil galleries as well.......Might be an idea to throw new vanos units on while you are in there.

[JimmySpeed]

[quote="IanP"]
I think to change the oil pump you will need to remove the front driveshafts and engine cradle to get the sump off. I changed my oil pump due to the amount of swarf that had been flying around, a lot had got into the oil galleries as well.......Might be an idea to throw new vanos units on while you are in there.
[/quote]

wow - that much work to access the pump! jeez!

the headgasket work cost £1100, I am in two minds to cut my losses now and not throw anymore money at it but 1) that would be waste of what I've spent already and 2) there is no way to do that now in any event as its not even saleable as is and 3) when it works its just an amazing vehicle

So frustrated! >:( >:( >:(

[IanP]

You might be better off taking the engine out.......

[JimmySpeed]

[quote="IanP"]
You might be better off taking the engine out.......
[/quote]

The mechanic said the same thing!

Its at his garage but he can't look at it until next week, maybe the week after

[JimmySpeed]

[quote="X5Sport"]
Could be main white metal bearings on the crank, camshaft bearings, big end bearing shells, timing gear/chains, or the oil pump itself has failed.  In any event it sounds expensive.  Is it steel or Ali swarf?

If they had the head(s) off, were they tightened down correctly and checked for warping and skimmed if needed.  Sounds like the engine wasn't re-assembled correctly to me.

Sorry you're not having much luck with this one....

Richard
[/quote]

Sorry Richard - I didn't see this response till just now.

I'm not sure if its steel or aluminium - I doubt I would know the difference but the mechanic said he would check when he re-opens (got there just before closing).

The head was sent off to a refurbisher, skimmed and all valves etc checked and refurbed where necessary. Compression has been checked and is spot on in all 8 cylinders now, and it runs super smooth. The sounds and symptoms certainly seem to be localized to the timing chain area and the oil pump is clearly not doing its job, but as Ian says that may be a result of blockage from swarf.

Thinking about it, the noise started before the oil pressure dropped enough for the warning light to come - I was driving in traffic and thought "that Nissan in front sound terrible" - turns out the sound was my car but only could be heard when another vehicle was in the next land and the sound bounced back at me. It got louder and then the oil pressure dropped.

Its not definitive but does support the theory that the chain guide went first, causing chain slap, creating the swarf which blocked the filter and pump...

I know its all speculation until its teared down but anything to help me sleep better tonight eh 

[JimmySpeed]

The other thing is I saw a funny looking shaving in the filter so I picked it out, expecting it to be metal but it was a very thin plastic shaving. There was metal in there too though...

[X5Sport]

If I remember correctly, the chain guides are plastic, and yes the swarf could have blocked the strainer so causing the pressure drop as the pump was not able to pick any oil up from the sump.

IMHO someone messed up re-assembling everything.

R

[IanP]

Yes the guides are brown coloured plastic. BTW I saw your post on A.N.other site, and it is possible to clean the suction fliter if you uncrimp the bottom. You will see what I mean when you remove it. I just changed mine as it was not that expensive in the great scheme of things