Oil Filter Housing leak

[GAZZEH]

Dear FCF members,
If you can help, please do it, your help is highly appreciated.
Noticed a leak coming from the Oil Filter Housing in contact with the engine and need to change the gaskets (part number:16 135 719 80)
As Citroën no longer has a dealership near me, a local mechanic said he must remove the exhaust to be able to dismantle the oil filter housing (as 1 or 2 bolts out of 4 are located behind the exhaust).
I found this strange. Why Citroën would hide the oil filter housing behind the exhaust, difficult to remove and time-consuming.

Do you think no way to remove the oil filter housing without removing the exhaust?
Thank you for your valuable help.
Karim GAZZEH.
Citroën C4 (B7), 120 VTi, Model year 2012, Engine (NFS) EP6C.

[GiveMeABreak]

Looks like it can be from either the Oil Filter Support on the Cylinder Block:

Sealing:
- 2 separate seals
- 4 bolts

Probability: Low
Possible Causes:
- Incorrect tightening of the fixing bolts
- Faulty seal
- Absence of seal
Access: Difficult
Repair: Replace the seal (Set of seals)

Or

Oil Pressure Sensor on Oil Filter Support

Sealing: Sensor screwed onto the oil filter mounting

Probability: Low
Possible causes:
- Incorrect tightening : Sensor
- Sensor faulty
Access: Average
Repair: Replace the seal

[GAZZEH]

Thank you GiveMeABreak for this reply.
The first possible cause needs to replace the set of gaskets.
The second possible cause needs simply to verify the sensor, which is accessible.

Regarding the 1st cause, can you please elaborate on whether I need necessarily to remove the exhaust to access the 4 bolts and replace the 2 separate seals?

If you don't mind, can you describe the procedure to replace the seal, including how to remove the oil filter support (housing)?

[GiveMeABreak]

I can't say for sure as I don't have access to this vehicle, but from the description it does state access as being 'difficult', so your mechanic will probably have a better idea. There's no specific removal procedure that I can see for this operation.

[GAZZEH]

Many thanks.
Let's wait for other contributions, they might have access to the procedure that Citroën uses.

[xantia_v6]

On the turbocharged version EP6CDT, some of the fasteners for the oil filter support are behind the heatshield behind the catalytic converter. So both need to be removed.

[GAZZEH]

On the turbocharged version EP6CDT, some of the fasteners for the oil filter support are behind the heatshield behind the catalytic converter. So both need to be removed.

Bad news for me. What about my particular version EP6C?

Because removing the exhaust, I guess, is a complicated task, isn't it?

[xantia_v6]

The job is awkward rather than difficult. Some of the fasteners are out of sight and the radiator is too close for comfort. At least you won't have a turbocharger blocking access from above.

[GAZZEH]

Thank you for those members who tried to help.
I had to remove the exhaust to access 2 bolts out of 4. Now the gasket has been replaced. Tomorrow will clean under the engine and the area around the housing to spot if new leaks occur. If yes, then that gasket was not the only source of leak.

[gwest]

Gazzeh, I note that the tightening torque for the oil filter housing to cylinder block is 10Nm. When I did the same job on my DS5 THP155 I mistakenly used 25Nm, before realising my mistake and backing them off. Two years later and I have an oil leak that I suspect is from the housing- I have not investigated it yet. In terms of long-term reliability using these O-ring elastomer seals is pathetic. But probably cheap.