Oil filter bypass stuck

[stewal 8]

Never seen this before but when changing the oil recently i was alarmed to find the removed oil filter completely dry: it was clear no oil had ever been through it in the 6 months it had been fitted.....

 

I assumed it was a faulty filter but repeated changes with different makes all give the same result. This is a recent issue: I have done numerous normal  oil changes using the same make of filters in the past.

 

There is clearly (unfiltered) oil circulating: the oil pressure light goes out and the guage reads normally so i guess there is a stuck bypass valve in the block?

 

The car is a standard 1.9 with no oil cooler and a filter that screws straight onto the block.

 

Anyone has any idea where this valve is and if it can be replaced without stripping the engine?.

 

cheers

 

Steve

[tartanbloke 35 1 Cars]

I think you have found your issue already...

 

The car is a standard 1.9 with no oil cooler

 

It is my understanding that the cooler circulates the oil correctly and without having this fitted, you are experiencing the outcome. I could however be wrong and happy for something to say so.

[Tom Fenton 1,542]

I don't think it is oil cooler related. Remember a 1.6 doesn't have one, and otherwise the oil system is the same. The only possibility would be if the sandwich plate is still in situ and the hose outlets are blocked off. But the engine would be scrap by now if that was the case!

I can't think where there is a bypass valve in the block but I'll have a look at one I've got later.

[stewal 8]

Thanks for your replies, I should have said it's the detuned  cti engine so never would have had a cooler and no sandwich plate as you say it's pretty much the 1.6 set up. 

 

I am told there may be a bypass valve in the block part of the filter housing but access is poor in the car so if you could take a look o the your block Tom would be grateful. 

 

Cheers 

 

 

[PhilNW 44]

Cant find any bypass part listed in service box

 

Is there a non return valve in the oil pump?

 

Has the oil just drained back to the sump through the oil pump, 

Edited July 25, 2018 by PhilNW

[stewal 8]

Found what appears to be the culprit on page 32 of the Haynes manual it's apparently built into the oil filter mounting face on the block above the threaded sleeve. 

 

Any ideas of where to find a replacement or how to get the old one out? 

 

Might just try flushing oil to start with... 

[Tom Fenton 1,542]

Not sure what you are looking at in the Haynes book but I’m sat here looking at my spare XU block and there is absolutely no way the filter can bypass. The oil comes from the pump straight into the outer cavity of the filter housing. It passes through the filter media and then passes back into the block via the centre threaded pipe. That pipe feeds into a gallery that runs “north/south” which then links up to the main oil gallery that runs “east/west” along the entire length of the block, just above 1/2 height of the block. 

[Tom Fenton 1,542]

I’ve just looked in my old Haynes book. That bypass valve isn’t on the XU engines. It’s on the old XV XW layback 1100/1300 Simca engines fitted to early base model 205’s until the TU engine came along in 1987 (-ish).

 

Are you sure the filters are dry? They have a tendency for oil not to piss out of them. Have you cut one in half to check?

[Tom Fenton 1,542]

 

[wicked 103 3 Cars]

Do you have a picture of the dry filter?

Afaik there is an overpressure valve in the filter itself.

[stewal 8]

Thanks for your info: I 'm stumped. 

 

There is no doubt the filters are bone dry like new. 

 

Whenever I have done filter changes over the years with this car oil has pissed out: now absolutely nothing. 

 

The filters all have bypass valves within them but if this was operating for any reason,  even then the filter would surely have oil in it? 

[Thijs_Rallye 87 4 Cars]

I don't understand how the engine can flow oil and not go through the filter . There should be at least traces of oil somewhere in the filter, albeit the bypass route in the filter internally.

 

(some more pictures with oil filter internals: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3389299/OEM_Renault-Purflux_LS218_vs_A )

[PhilNW 44]

There is a messy way of proving this ,take off the oil filter, disconnect the ignition system and spin it on the starter for a couple of seconds  to see if any oil comes out

[welshpug 1,661]

check the crank pulley bolt!

[Richie-Van-GTi 72 2 Cars]

Are you sure it's circulating oil at all, have you took the cam cover off. Pretty sure the car would of down by now if it wasn't but no idea how much you have used it. I have literally smashed a couple of the alloy blocks up before and never found any evidence of bypass valves in the oil system other than the non return valve in the good quality filters but even they have evidence of oil running through on removal.

Have you still got the old filter that hasn't had oil in, take a grinder to it and check you are right??

[stewal 8]

Without a bypss built into the block I can only conclude that there must be a breach between the gallery feed from the pump and the main gallery from the filter and then i guess the oil will take the path of least resistance and bypass the filter.

 

will try and find time to take the sump off and take a look.

[davemar 16]

Did you ever get the answer to this one?

 

I've just taken my oil filter off and it is also totally dry. It looks like oil has never passed through it.

 

The car has been sat for a couple of years, but I recently restarted the engine on the original oil and seemed to run OK (ignoring manifold leaks and that I can't drive it yet). So I would have expected to see some traces of oil on it from the recent run.

 

I also removed the sump at the same time as the oil filter, as there's a bit of a leak from the sump, and the oil pump and nether regions of the engine looked suitably oily.

 

[stewal 8]

Dave: it was all a bit bizarre really: I replaced the filter and ran it and oil was circulating ok again. The problem filter was the correct one but the only conclusion I could come to is that it was a manufacturing fault with it  - but quite how it could stay dry and still extinguish the oil pressure light and register on the gauge had me baffled.

[stewal 8]

Should have added mine has a/c and consequently required the much smaller filter to fit past the compressor. ( same diameter, thread etc just shorter) All of these filters remained dry after fitting.

 

I removed the compressor and used the full size standard filter and oil was in the filter again.

 

Is yours using the smaller filter perhaps?