Oil in header tank - cit bx

[Geoff Lebowski]

Xud 9 block bored to make a xud11 - block of unknown/untested origin.
Head from my pervious trusty bx steed. I did unwittingly run this head for about 5 minutes without coolant!!
Warp check on head showed to be in tolerance - just.
New mls 2.1 gasket and new bolts torqued to Cit spec for 1.9td which is a bit tighter than 1.7 td.
Emulsified Oil in header tank and water globules on dipstick.
Can't see bubbles in header tank.
Starts and runs very well.

Possible causes in order of preference!
Do bolts need to be tighter for a larger bore?
Porous oil cooler - does this happen?
Need head skim?
Porous head?
Porous/cracked block?

Have I missed anything?
Has anyone pressure tested an oil cooler? Shouldn't be to tricky? I have a compressor.

[CitroJim]

Hi Geoff, check the oil cooler if all else appears good. They are known to fail...

[Geoff Lebowski]

Hi Jim,
I did wonder, but I've never had one fail on me before so I was in the dark a bit. However, I will elaborate as I think all might actually be ok.
As I wasn't sure if the engine was going to work (in theory yes it should but you never know!) I re-used the old head bolts just to save on my tight budget. Not only was I a tad ginger with the final angular tightening, but I've since discovered I used a much lower angle than hbol specifies. This led to the oil in the header tank and indeed bubbling. I then bought new bolts and tightened correctly. This I assumed had solved the problem. It was last night that I thought I'd check the coolant level and found the oil again. My hope, is that the trip to the mot station and back has flushed any remaining oil to the header tank and provided a false alert that all isn't well. I've just been out and cleaned the header tank as best I could, so after a re-test on Monday, I'll run it about and see if I get more oil. Will keep you posted!

[CitroJim]

Ahh, now I understand Geoff... Hope that's all now good and that was just a bit of remaining oil from earlier in there... Fingers crossed..

Let us know how it goes...

[lexi]

Maybe take a few flushes once you know it has stopped leaking. Is this a big growler 2.1td in a BX?

[Geoff Lebowski]

Thank you both Jim and Lexi - I will keep you posted. Lexi It's a 2.1 (xud11 crankshaft and Pistons) inside an 1.9 td lump. Normal xud 8v head. Goes rather well although I've only driven to mot station and back - about 3 miles in total!!

[lexi]

Sounds excellent and best of luck with her.

[Zelandeth]

Having played this game on a Jag XJ6 I can attest to the fact that it can take quite a while to get shot of the oily gunk in the header tank. If you can easily give the radiator and heater matrix a thorough reverse flush, it's worth it as quite a lot of it clings in there.

Do imagine that will make a BX shuffle along quite briskly given that I don't find my Xantia lacking in get up and go despite being a standard (as far as I know...the jury is still out on whether the fuel pump has been lightly twiddled with) XUD9TE.

[elma]

Check if theres a locking collar on the adjustment nipple between where the diesel pipes enter the pump Zel. If it's still there then your pump hasn't been turned up.

[Old-Guy]

I can attest to the fact that it takes a lot of effort to clean an XUD cooling system of oil and you'll never get it all out! The problem with flushing is that as the coolant drains down, the oil floating on the surface gets spread downwards onto all the solid surfaces of the cooling system.

What has worked for me is to attach small strips of oil absorbing mat to the bottom of the level-indicating insert in the header tank, changing the strip whenever it's saturated with oil.

See page 612 of the Spill Control Section of this Pirtek Catalogue; explain what you want at the parts desk of your local Pirtek depot, you might get given a piece of suitable map for free!

Loosely, but securely, attach a strip about 30mm x 100mm to the bottom of the header tank insert with a cable tie. Make a generous loop so that the tie can be cut and refasten when the strip is loaded with oil. The strip will also be soaked with coolant which will readily drain off (DO NOT SQUEEZE) leaving the oil trapped in the mat. I changed the strip every time there was a trace of oil floating in the tank - half-a-dozen strips, two years and 10,000 miles later, the coolant is staying clean though the current strip is black again.

[CitroJim]

Guy, that's a good tip to clear any oil...

[myglaren]

I wonder if Forte's Cooling System Flush would help?

[Geoff Lebowski]

Thank you all very much for your advice and support. I'm slowly coming to the realisation (or deluding myself) that the problem is indeed fixed but it is residual oil making me think that it wasn't. She's in for re-mot tomorrow and pending a pass, I shall run her about and see how things pan out. If all seems ok, then I shall indeed refresh the relevant fluids and use the oil absorbant mat as suggested by 'old guy'. Although, it has crossed my mind to use a dilute degreaser in the cooling system for a three mile round trip and in the same day flush out and replenish with proper coolant. Can any one see a harm in this?

[Stickyfinger]

Personally I wouldn't, most are based on various "salts" and that is not great for the internals......I like the mat

[ken newbold]

Drop a dishwasher tablet in and run it for a couple of days, then flush and refill.