Td5 major oil loss - what just happened?

[mools]

So there I am driving along the highway, running normal - normal temp, normal EGT and normal oil pressure when suddenly - oil pressure alarm goes on and smoke. Pulled up very quick and shut it down (all under a few seconds). popped the bonnet. Not a pretty sight - lots of smoke, lots of oil (under the bonnet, on the road, under the vehicle). Let it cool down and had a poke around. The top of the rotor filter had been blown clean off, turned through 90 degrees and resting loosely on the filter housing, the threads of both the securing bolts were filled with the housing i.e. stripped the ali housing out when they gave way.

Whilst waiting for the tow truck I did check with the nanocom but no faults were registered, coolant is all still there and clean. My madman had logged an oil pressure max of 10 bar!

Its now parked outside a garage waiting for monday to come. Looking like one sick puppy at the moment,.

What could cause such overpressure in the oil system? What else (apart from the filter housing) will have caught a flogging during this? Has anyone else suffered a similar incident?

I can't fathom whats gone on but suspect that it's going to cost me an arm and a leg to get it sorted. Views and similar experiences sought.

Ian :(

[goingbush]

10 bar is 150 psi, with that sort of oil pressure, like 3 times whats normal I'd have thought you'd been running on oil fed past the turbo seal and into the inlet tract & noticed smoke & over revving before any catastrophic event.

My guess is the oil pressure was fine but the madman sensor was faulty

The relief valve should have blown first.

Who does your oil changes, My guess is the bolts on the rotor housing were over tightened & stripped, just waiting to blow off ???

[djam1]

If you genuinely had over 140 PSI oil pressure I would of thought that the Oil Cooler would have burst leading to oil in the coolant and major coolant loss.
I am sorry for your situation hopefully it was a simple as the threads being stripped mine have helicoils in them because they too were stripped by over zealous mechanics.

[Blknight.aus]

Pics?

I can buy 140psi not pushing out the turbo seals as the turbo seals dont see full working oil pressure as the drain is a lot larger than the supply.

Im going to guess that the drain from the rotor housing got blocked stopping it from draining, 40 psi over the area that the housing covers would easily pull the 2 m8s out of the ally.

but excluding that..

the oil cooler is drain to sump so in theory shouldnt see any working pressure as it offers little to no restriction to flow, the rotor filter does so lets play with this scenario.
(edit its full pressure and cools the oil Before it goes into the galleries and not the bleed off oil from the filter, had my head in the wrong department)


1. the relief valve has jammed closed
2. the oil pressure being fed into the rotor filter has skyrocketed (its skyrocketed everywhere but in this case the rotor has been the component thats failed)
3. the filter has overspun and stalled onto the shaft (or its been completely blocked from not being changed)
4. the pressure has built inside the rotor filter untill its burst and the stored energy has smacked the filter housing off.

[mools]

Ok Dave thanks. Well I don't have the knowledge to argue against any of that, and wouldn't argue anyway, after all I'm after opinions, and that all sounds reasonable.

For what it's worth here's the only picture I took it's of the stripped thread (well stripped housing in the thread of the rotor filter cover) both bolts were the same. Like I said it was resting on the rotor filter but 90 deg. out of place when I found it. The rest was, well an oily Td5, not very photogenic! The rotor filter was intact, undamaged and span freely when I whizzed it round with my hand.

I changed the filter out about 3000km ago, along with oil change and usual service (about every 6K all filters and oil) and I torqued the retaining bolts up to spec using a torque wrench as was aware that it was somewhat vulnerable to over tightening.

41301

I had some oil loss since then but had though it was down to a leaky rocker cover gasket that I had been meaning to change, it may have been getting worse very recently (judging by the larger than usual oil stain on the driveway I can now see in it's absence). The day before the incident I had topped it back up to full on the dip stick (took about quarter liter).

Now I think about it while back after a service I remember an un explained oil leak (possible discharge) from a similar area (passenger side of engine). Would this be where the relief valve is?

It's at the garage now, they'll get back to me tomorrow (I hope) and let me know what they reckon, still wondering what the cause could have been and what the damage may be.

It was running at about 2.3 bar oil pressure most of the time - which I took to be normal. Although this would drop to 0.9 bar when I came to a standstill triggering the low pressure alarm. I thought nothing of this.

Are there any things that I should ask the garage to look at in particular? All this is a bit beyond my comfort zone.

Cheers for your input.

Ian.

[Blknight.aus]

the relief valve should be part of the pump setup.... (going to have to have a dig through the books, sometimes it forms part of the gallery the pump bolts to and sometimes part of the filter assembly)


check the return drain for the rotor filter housing, if thats clogged theres your culprit.

else Id suspect that youve had a combo of the bolts being done up over enthusiastically one time too many and its finally let go combined with a spike reading when the cap blew off... Ive seen some interesting results from diesels when a contaminant in the oil has spontaneously ignited in the sump...

[mools]

Thanks Dave. Any info on the releif valve, operation, location would be of benifit, if not just for future referance. Is there any way of (manually)checking it's operation say at the service interval? I honestly have never heard it ever referred to.

If it was near the filter housing would explain the mystery oil leak I had some time ago.

I can't think how it would have got any contamination in the oil to make it block though.

Fingers crossed for the report from the gararge now. Although the longer it takes the more I fear.

Ian.

[Blknight.aus]

The relief valve is part of the pump assembly, the only way to check it is by operating the pump and measuring the pressure it puts out. the easiest way of doing this is with a gauge in the oil pressure senders hole and running the engine.

The oil cooler is a full pressure item. and deals with the full pressure of the system when the oil temperature is high enough...

[djam1]

FYI

TD5 Very high oil pressure - SA 4x4 Community Forum (http://www.4x4community.co.za/forum/showthread.php't=79080)

[mools]

Thanks for your input(s) on this. I guess we'll see in time what the culprit was. At the moment it seems that all was well prior to the incident - all oil pressures normal at idle and at running and had been since I fitted the pressure monitor some 9 months ago. Then something went wrong and the **** hit the fan.

I can pretty much discount the oil pressure reading being wrong as my sensor oil pressure sensor worked OK and (destructive) evidence suggests significant over pressuring occurred, cause of which as yet unknown. The relief valve appears, therefore, to have failed to work.

I guess the best I can really hope for here is that historical over tightening of the dizzy filter had created a weak spot which allowed failure to occur in one spot and not across multiple seals etc. The oil cooler, which appears to have escaped a bursting, may suggest this. Alas time will tell - will no doubt hear from the garage tomorrow.

keep you posted.

[djam1]

Mools any news??

[mools]

Just got back from picking it up. They fixed the damage to the threads on the dizzy filter housing (using helicoils as I expected they would). They also said that they checked the operation of the overpressure valve and that it was OK and the engine had not over pressured.

I was told, but not sure I beleive, that if the threads on the filter housing cover are shot then it would not have to have over pressured to spew like it did. Apparently whilst not common they have sen it a few times.

To be honest I could have done the filter housing fix myself but wanted to take it to a gararge because I feared the worst. They say there is no lasting problem - I'm (with no reason to be so) unsure.

Like every other engine that has ever let me down I now feel a bit sceptical about it. I guess I'll see, time will tell. Up to now it's been utterly reliable and I really hope that that continues.

If there are any tell tail signs of deeper damage I should look out for I'd be interested to hear.

I'll update this thread with any development and try and relax a bit.

Thanks for the input, advice and concern shown.

Ian.

[Sitec]

If it's any consilation, I did an oil change on my 99 Td5 a few months ago, and was told beforehand that no matter how delicate I was I would strip the centrifugal filter cap threads, it was common, and that if I didn't, it'd have helicoils in it! Sure enough, one came out fine, the other came out feeling fine but there to see was the alli thread on the M6 bolt! With a torch I could see one Heli coil and one threadless hole... Not happy! having had a better look, the stripped hole had lost 5 threads but deeper in the hole there were still a decent number of untouched threads! So, one longer bolt later and I was back in action. Note, there is now an M6 heli coil kit in the truck as there will b a 'next time'!

[Blknight.aus]

amazing how many places say that, Ive never stripped one personally yet..

those bolts have a torque spec and 11nm is within torque SCREWDRIVER range and below most torque wrenches.

[Sitec]

Yeah, 11nm.. only a bit more than finger tight! frightening!!