BXProject

[David]

This is slightly wierd.

BX I've just put the head back on to is exhibiting some rather odd symptoms.

History:
This is DavidB / Marty / My landlord's old BX. A TZD turbo with retrofit aircon. About 9 months ago, the aux belt shredded on a badly aligned pulley and wrapped itself around the cambelt, slipping it several teeth. Pistons met valves. Camshaft in numerous pieces. Bottom end unmarked, head wrecked. Standard stuff.

Old head off. Replacement head (from a 1.9TD 405 I ought to add) skimmed and fitted. BX N/A camshaft fitted. New cambelt. Only thing "wrong" is that the oil strainer for the turbo in the feed pipe crumbled when it was removed, so the pipe was re-installed with the strainer missing. I've never found anything in one of these strainers, so I've no issue with that, but it does alter the seal at the end of the pipe....

Started the engine today, and it appears to have issues with gaining oil pressure. The sump plug and old oil filter were left off for about 3 days, so the pump and galleries will have drained completely. It has a new oil filter and a fresh sump of oil. If the engine is revved to 2000rpm, the oil warn lamp flickers a bit, but won't go off completely. I've run the engine for about 30 seconds in total.. surely that's enough to fill the filter, oilways, turbo etc and gain oil pressure? I can't run it for any longer at the moment as the cooling system isn't back together yet, but I am concerned as usually on an XUD the oil lamp is out within a few seconds.

What have I missed?

[mat_the_cat]

The only thing I can think of would be the feed to the vacuum pump - but I'm certain you'd find it difficult to miss an engine bay full of oil!
If you have another pressure switch I'd be inclined to try it perhaps...

[Philhod]

I think the clue is in your info David. The pick up point on all engines is very important.
Too high in the sump and it gives exactly the symptoms you describe.
Too low and you usually get no pick up at all and therefore no oil pressure, even though it's filled with oil.
This occurs when the strainer is less than 1/4" from the sump floor.
I've actually measured it once on an Escourt mexico. but optimum distance for the pick up with strainer would be between 1/2" and 1" .
The Mexico was showing your symtoms after rebuild (without strainer) Fitted strainer but noticed that pick up pipe was bent and straightened it (too much) ergo no oil pressure.
bent it up some and magic, aok.

[docchevron132]

Or... it could be that the pump is a bit weak and having had three days to drain wont pick up anymore. Equally, the pressure relief valve could have stuck?

[jonathan_dyane]

Assuming that the sender hasn't gone bad, it looks like you're going to be dropping the sump and taking off the oil pump to check and fill with vaseline.

Never left a XUD without oil, but have encountered other engines which have been left without oil and have then struggled to reprime. Strange one though...

[David]

I think the clue is in your info David. The pick up point on all engines is very important.

The issue with the strainer is in the oil line to the turbocharger where the feed is screwed into the back of the block, nothing to do with the oil pick-up in the sump...

And Doc, yes, I thought similarly.. an oil pump that just won't prime.. but I've never heard of that before on an XU engine...

Turns out that the engine does have oil pressure after all. Running the engine with no alternator belt on means I should have a battery warn lamp, and no oil pressure lamp. What I've got is the exact opposite. Yes, someone has got the oil pressure wire and the alternator exciter wire the wrong way around. Just blind luck that they are wired similarly in the dashboard so that they both still worked, just the wrong way around.

Just like a number of things on this car really. The A/C is nice, but the installation is a bit crappy. The addition of a one-touch system on the passenger side is nice, but the system doesn't work properly (can't be controlled from the driver's side) so it's crap. The problem I've just found is undoubtedly related to the installation of a GTi set of clocks. Nice to have the temperature gauge, but the installation is crap.

Ah well, at least the engine works....

[Philhod]

Oh you mean the little plastic thingy in the pipe.
I've left those out before as they don't sell them separately. When I rebuilt the 2 litre HDI last year it split. I superglued it back together and refitted and it's been fine.

[Bx Bandit]

Assuming that the sender hasn't gone bad, it looks like you're going to be dropping the sump and taking off the oil pump to check and fill with vaseline.

Never left a XUD without oil, but have encountered other engines which have been left without oil and have then struggled to reprime. Strange one though...

Just out of curiosity mate what's the vaseline for? (see, I always pick up on the word vaseline )

[mat_the_cat]

It's something that will stay in the oil pump and effectively 'prime' it so it can suck up the oil from the sump. I *thought* the XUD had the pump in the sump anyway, so would be self priming?
I've had to use vaseline several times on Rover V8 engines as the pump is above the sump, although if it's just because it's been left for a while (rather than after a rebuild) you can sometimes get away with whipping off the dizzy and spinning over the oil pump with a drill.

[Bx Bandit]

Coh! Vaseline eh? So......................... many uses

[mat_the_cat]

I guess priming an oil pump is something that you can't use the old 'spit on your hand' method for?

[David]

I've had to use vaseline several times on Rover V8 engines as the pump is above the sump, although if it's just because it's been left for a while (rather than after a rebuild) you can sometimes get away with whipping off the dizzy and spinning over the oil pump with a drill.

Had to do this before on a kit car I was assisting with. Beautifully rebuilt 3.9 engine, and when asking the guy who built it about it I casually asked "oil pump full of vaseline ready is it?" "No. I didn't like the sound of that so I didn't do it."

Hmm. Dizzy out, driveshaft made up, and pistol drill running at 2000rpm. Took about 1 minute to achieve any pressure at all (engine would no doubt have been ruined by this number of revolutions) and then another minute to get good pressure and decent drainback.

Worked though...

[charlie]

Just out of curiosity mate what's the vaseline for? (see, I always pick up on the word vaseline )

meanwhile down in the bx sewer

mr bandit is hard at work

and i take advice off this bloke

[Philhod]

Just out of curiosity mate what's the vaseline for? (see, I always pick up on the word vaseline )

It lubricates all mating parts and makes things slide in and out smoothly, ye great twonk

[Bx Bandit]

[smiffy]

Right then boys and others, as some of you may know, I want to fit an oil pressure guage to my car, and I want to know if anyone can recommend an off the shelf T piece adaptor to go in the engine block? When I next do an oil change, I will also swap the sump for one that has a temperature probe in it.
You can never have too many toys and dials on your car!

[Philhod]

Provided they work!!!!!
You can but T pieces with a screw connector for the gauge and an electrical terminal at the other.
Good quality Gauge kits come with one in ready

[smiffy]

trouble is I don't know what thread size the pressure switch is. I think the gauge sender is M10x1, but as for the light switch, I don't know. Of course, I then have to make up a small wiring harness for it, together with the oil temp, and the red light of death too!

[smiffy]

been snooping around, and I gather the oil switch is M16x1.5....nobody makes a t piece with M16, and M10!

[mat_the_cat]

Just get an M10 oil switch! That's what I did. Simplez.