[Corsa B 1993-2000] No oil pressure after oil and fiter change change - blockage??

[zuluman]

x10xe engine 86k miles


Any help appreciated as I am in the countryside with no car for Christmas :-(


So here is the story:

Slight whirring noise from engine

Decided to change oil and filter

Drained old oil

**Filter badly damaged - broken

*Washed out filter housing with diesel (did not remove filter housing from engine when I did this)

*Poured some diesel via oil filler opening to generally wash out orifices in engine

Replaced filter with Crosland filter

Added 3 litres new 10W40 Magnatec

Started car.

Whirring noise still there. Then died away. Car ran smooth. All ok

Turned off car

Started car approx 10 min later

Car now very noisy (sounds like no oil on timing chain and in top of engine generally)

Oil pressure light on

Changed filter for a coopers FIaam

Made no difference

Removed oil pressure switch

No oil pressure at all

Removed oil filter housing

Oil squirting out of centre hole on block, where the filter housing would be attached (feed from pump to filter)

I can hold this oil flow back with my thumb (I think this is correct ? as the oil pressure should only be ca 21 psi)

*Thus oil pump is primed and working (????)

I am thinking that either the filter housing is blocked OR the orifices between filter hosing an rest of engine are blocked OR both

Blocked with part of the filter AND/OR crud from the diesel wash??


What do you think?

How can I clean the orifices in the engine?? With air compressor or drain oil and fill the orifices with diesel and let it soak???

Any help appreciated (hope big ends are not now damaged)

[Taurus]

It's a fairly common issue if aftermarket filters are used in them. The filter cartridge disintegrates and the debris blocks the oilways.

By the sounds of it the pump is picking up oil from the sump but it's not getting back from the filter into the block, which makes sense if you think about the filter debris causing the blockage. Clearing it depends if you can identify where the blockage is and clear it - as you say, check the filter housing and then the flow back into the engine. Hopefully you might be able to see what's causing the blockage and get it out.

If you haven't run the engine under load you'll probably have not done any damage - best of luck with it.

[zuluman]

Thanks for confirming what I thought

If I cannot see a blockage would letting the oil galleries soak in diesel overnight help?

Are Hengst filters, the best to use in these or just change the aftermarket filters at ca 1000 - 2000 miles or upon inspection?

She got run for a mile on the road (half mile down and back) in this condition, so I hope there is no damage

To this end, I do not see any shards in the oil

I will take off the sump and have a look too for damage

[Rob]

best filter is genuine gm. i wouldn't be starting it with no oil pressure.

[Taurus]

I use either genuine GM filters or Mann. Part of the problem is that some aftermarkets are actually slightly the wrong size so they distort and can break up very quickly.

In terms of clearing it I think you'll need to make a tiny hook on the end of a length of welding wire or similar and have a fish around. Diesel won't soak it out - you will need to physically clear it. The snag is you can't easily see there without removing the radiator and grill.

I remember an article a few years back where they drained the oil out of an engine and ran it round a track, expecting it to seize more or less immediately - it actually ran for quite a long time with no problems - so you may have got away with it. The main issue with oil is when people leave old oil in for ages as the damage is cumulative.

[zuluman]

No more starting.

I just started it to see if oil pressure was present on the filter line- saved me stripping the engine to look at the oil pump.

what a mess so close to Christmas

[zuluman]

I use either genuine GM filters or Mann. Part of the problem is that some aftermarkets are actually slightly the wrong size so they distort and can break up very quickly.

In terms of clearing it I think you'll need to make a tiny hook on the end of a length of welding wire or similar and have a fish around. Diesel won't soak it out - you will need to physically clear it. The snag is you can't easily see there without removing the radiator and grill.

I remember an article a few years back where they drained the oil out of an engine and ran it round a track, expecting it to seize more or less immediately - it actually ran for quite a long time with no problems - so you may have got away with it. The main issue with oil is when people leave old oil in for ages as the damage is cumulative.

Never knew that about he aftermarket filters

I have the fan already removed and the upper heat shield (to better access the filter housing bolts - plus I will drop the exhaust at the cat to manifold joint to get the sump off)

So rad and grill not such a big thing

I think it should be ok too in terms of damage

Here is hoping.

Thanks for the help! will report back

[zuluman]

Washed out filter ousing - no blockage - large bores in it anyway - too big to block


So took rad, Grill and front bumper assembly off.

Ran a thin brass rod with a small hook on end down the galleries which are visible when the oil filter housing is removed - to no avail - only got down a few inches anyway before the junction on the gallery was hit

I took the camshaft cover off. I removed the timing chain guide. I put the rod down that gallery but no blockage - rod did not go far

Put the rod in the pressure switch gallery to no avail

Should I put the air compressor on the chain guide and pressure switch galleries and try and blow out any possible blockage ??

i would then be blowing in reverse and not forcing any debris INTO the engine. If i blew from the oil filter housing, I would be forcing debris into the engine.

If I took the head off, would I be able to access the galleries better?


A question on pressure:

As I wrote yesterday, there is pressure as far as the filter housing.

I can hold the pressure back with my thumb.

From your experience, is this about the correct pressure or should it be much higher???

regards

[Taurus]

I think you're misunderstanding how oil pressure works. Oil is picked up from the sump and pumped into the filter, and from there to the engine. It is pumped, not compressed, so its pressure is actually quite low at that point. When it gets into narrow galleries that's where pressure builds up, and of course it's influenced by parts being in close fit (ie main bearings having designed clearances - which is why worn bearings cause low oil pressure - there's less resistance to the oil flowing through them.) That's a crude way of putting it, but don't be looking for oil pressure when the system is running as yours is now.

Having said that if the pick up is clogged then even a healthy pump won't deliver enough oil to enable pressure to be established - due to flow rate rather than pressure per se. In which case the first thing to do is to drop the sump and check the pick up. Simpler to do that than remove the head.

In reality the blockage could be in the galleries from the filter to the head, in which case blasting air down from the oil pressure switch will probably just move it along the system rather than blowing it clear. So removing the head and cleaning systematically is the only real way to approach it. But I'd check the sump first just to make sure.

Something you might try - though no guarantee - is to feed fresh clean oil via the pressure switch port at low pressure to see if it just might float any debris back out of the inlet. How you'd do it would need some bodging - a large syringe might work if you can make a bung to feed it into the switch port. It depends where the debris has got to so it would be a long shot, but so long as it's done gently you won't do any harm. Never tried it, but there's always a first time for everything.

[zuluman]

Thanks, I will try that with a syringe or something makeshift

I could also syringe the port at the chain guide

I have the sump and bell housing bolts removed - just gently trying to get the sump off.

If a thorough clean is unavoidable, do i have to remove any oil plugs in the block?

Are they screwed in ? where would I get replacements

I think a replacement engine would be quicker to put in. I could look at my engine then in peace

[Taurus]

General rule is to dismantle as little as you have to. Check the sump pickup first and take it one step at a time from there.

[zuluman]

Yes, will investigate sump.

Got a syringe from the pharmacy today.

Will keep posted

[zuluman]

Stripped off sump.

Oil pickup clean.

A few cruds - like a paste in sump from older oil - nothing major

I blew into the oil return pipe with my mouth, which terminates in the sump.

No apparent resistance pressure - feels clear.

Port for <oil pump appears clear - little pieces on edge of port - could be pieces of Gasket?

Removed baffle

No shards to be seen in sump or baffle

Removed relief valve - looks clean. Moving freely

What is the function of the one way valve which is located above the relief valve but is accessible from the outside of the engine?

It is above and to the left of the port for the TDC tool when setting the timing?

The search continues

Happy Christmas all

[Taurus]

Oh dear - it was worth checking the pick up - you've got to make sure - but it sounds like it's the upper gallery area which is 'downstream' of the filter housing.

Re the valve - I think you mean the parts labelled 3 & 18 on this - Vauxhall, Corsa + tigra 1993-2002, Engine and clutch, X12xe petrol engine, Oil Pump And Fittings OEM parts and accessories illustration

[Rob]

only way now is a full strip and rod all the galleries.