Oil draining from filter after oil and filter change

Cheap aftermarket filter without one-way valve? It's for this very reason that Saab enthusiasts will only fit genuine Saab filters.

The only thing you can do about it is to replace the filter again, but be more fussy about the make & specification.

Thanks for that :-)

Interesting, I never even realised that there was a one-way valve in oil filters. It is a Halfords filter, which I thought were OK - I take it I was wrong about that?

It only comes into play in the event that a filter is fitted above horizontal, i.e. with the open end below the closed end. The catalogue they use to select your filter may specify whether it has an anti-drain valve and/or a bypass valve. I have an old AC filters catalogue which gives this info.

I would go back to halfords and check the catalogue, stressing that you believe they have sold you the wrong filter. Take the number of the filter, check the book in the store, and if it gives a different filter from the one thy sold you, insist that they change it for you. Make them fit it.

Steve

Why on earth are you buying filters from Halfords when the genuine GM is less than 3quid?! Their 10w-40 semi synth oil for 9 quid is a bargain too.

Even less if you;re in the trade club.

Tim..

Is this a newer engine with the replaceable element or the older engine with a spin on filter?

Regardless off the engine, there is no one way valve in the filter (there is a pressure relief valve/spring in the spin on filter so the filter is bypassed if it blocks, but it doesn't affect oil drain back). Depending on the engine there could be different faults.

I think it s called drain-back. Maybe on this engine there is a valve which is stuck open or leaking.

or maybe the oil filter should have a flap valve fitted, but has not.

Try fitting a new filter and see if the problem goes away?

(Assuming there is enough oil in the engine that is - or are you parking on a sideways slope, which leaves the oil pickup pipe above the oil in the sump?

What part number did they sell you, and exactly which engine do you have ?

It was part number HOF226, and it's the older normally-aspirated 1.7 Diesel (made by Isuzu I believe). I might add that there were no problems before I did the oil change, but it's started happening immediately afterwards, so I doubt it would be a problem with the engine itself (which has only done

15,000 anyway).

It's the older engine (late 2000) with the spin on filter. The engine has

15,000 miles on it only and it was fine until immediately after I did this oil change.

Are you *sure* it's a normally aspirated engine?

The once badged "1.7 DI" as opposed to "1.7 DTI" were still turbocharged.

Don't know the exact difference between the two, but I know they were both turbocharged - maybe one was a lower power version or something.

Peter

This is where the confusion comes in.

In the old astra-f, in the last few years off production you could get either the GM 1.7, or the Isuzu 1.7. The GM engine was originally used as a normally aspirated engine, but to clean up emisions and get a couple more years production out it, they added a low blow turbo. They also used the Isuzu with a higher output turbo with an intercooler. Then when they went onto the Astra-H, they done away with the 1.7 GM engine (the 2.0 GM was an option), and used the isuzu engine. It was still turbo'd, but I'm fairly sure it was only a low blow (from what i remember at work, the 1.7s were only used for pool cars, with the 2.0s being the preferred choice for group managers). About 2000/1 the Isuzu was changed to fly-by-wire and Direct Injection, but my works contact with Astras diminished as the standard company car was changed to a Vectra.

From what I remember all the 1700 astras had a front mounted oil cooler, which on some cars was prone to leaking either at the cooler itself, or the connecting pipes.

I have also seen an oil pump fail on one off the diesels, which could give the symptoms you describe. Personally, I'd be looking at changing the oil and oil filter again (you did use the correct grade oil???). If that doesn't cure it, then the next step would be an oil pressure check, to ensure that the pump is working correctly.

The fact the engine is low mileage doesn't mean a thing. Low mileage would indicate the cars been used for short journeys, which will wear an engine far quicker than if it was doing long journeys.

just in case this hasn't been covered before, there is a one way valve in the filter that stops the oil from draining back into the sump on most filters it is clearly visible at the base of the filter body (if you look through the hole)

unless youhave one of them different filter set ups it should be easy to go back to halfords and see if the other filters in the box have the same clear to the back of the filter or valve fitted

on a separate note, I'm going to link this someone so if you get strange questions from people, you can blame me :)

That valve is not a one way valve. It is a low pressure bypass valve, which allows oil to bypass the filter element should it become blocked.

Some filters incorporate a simple one way valve in the form off a rubber seal/flap just below the oil entry holes into the filter (that's the holes between the centre hole and the outer seal ring).

it was explained as the valve that stopped oil returning to the sump from the system after you turned off that way you had oil in all the important nooks and crannies when you fired up again in the morning

I'm afriad the one-way valve is just that. The valve you can see down the center hole is indeed the by pass valve if the filter becomes blocked, but the one way one is just visable through the small holes and take the form of a rubber flap which seals against the steel end of the filter. (oil direction is through the small holes and out the center one)

Tim..

Just to let everyone know, I got the filter exchanged at Halfords and everything is now bak to normal, with the oil-prssure light going out after a couple of seconds.

Interestingly, the warning light went out after about 10 seconds after putting the new (and completely empty) filter on, which suggests there might have been more to the faulty filter than that it was just letting the oil drain back, as it was keeping the light on for at least a minute after every engine start.

I'm going to have to think hard about Halfords stuff in future, one of their batteries packed up on me after a few months as well, which either means that I'm very unlucky or their quality control isn't all that it might be. Unfortunately Halfords is just round the corner, but I don't have any Vauxhall dealers around for miles :-(

Many thanks to you all for your help.

And for a one way valve to work it must be combined with a centre tube running from the neck by the thread to very near the base of the housing and overlapping the by-pass valve unit.

Huw

Next time you change the filter part fill it with clean oil and you will find that the oil light extinquishes quicker!

Did they give you another filter of the same part number ? Or did they give you a filter with a different part number ?

ie was it a faulty filter, or had you been given the incorrect filter ?