V6 fuel filter change

[elma]

Coolant change about to start then I'll be swapping the fuel filter. I don't know where it is though, assuming under the rear door. Is there a procedure for changing it to depressurise the fuel or do you just undo it with a rag over the union?

I'm quite enjoying having to ask so many questions again, I'm lost in this engine bay at the moment.

[Mandrake]

You should definitely depressurise the fuel rail before trying to change the filter unless you like a face full of petrol. (been there done that)

The easiest way to do this is locate the fuse for the fuel pump in the under bonnet fuse box (it has a fuse all to itself) then with the engine idling pull out the fuse - it will keep running for a few seconds then splutter and die as it runs out of fuel. After this the fuel rail pressure will be minimal.

Leave this fuse out until you are finished the job because the engine ECU on the V6 will activate the fuel pump approximately 3 times over a period of 20 minutes or so for about a second a piece even if the key is removed and the doors are locked! If you happened to be looking at the end of a disconnected fuel line when this happens you will not be a happy chappy...

This is done to keep the fuel rail pressure topped up as the engine cools to minimise vapour locking.

And yes its under the right rear door - easy to get to and has the safety click lock connectors.

[elma]

Perfect thank you. The handbooks been unusually useful, fuse 7 15 amps.

[elma]

All went well, an alarming amount of unleaded did shoot out anyway. About to take some pics and go for a spin.

[elma]

Spin was smooth, old filter was manky. Made a world of difference, looking forward to getting the spark plugs and engine oil changed shortly.

[CitroJim]

James, take heed of Simon's advice on which spark plugs to use... His Bosch recommendation is mine too.

And make sure you have a new inlet manifold gasket as to do the rear bank the top half of the inlet manifold needs to come off. The part number for the gasket is 0348.K7

When you take the coil off, give it a good clean and don't worry if it appears to have a few cracks in it - they all do in my experience!

Look for oil in the spark plug wells.. The plug well by the oil filler may be quite full and this will be a result leakage when topping up the oil during an oil change. Oil in the other wells may point to cambox leaks...

Soak up the oil and before removing the old plugs give each well a blow out with an airline to remove any debris - otherwise it'll fall into the engine when the plug comes out...

Plugs may be tight... I find it helps to remove them with the engine still warm and if they are tight work them backwards and forwards in gentle stages until they ease off...

Be careful starting off the new plugs.. The wells are deep and it is easy to start a plug cross-threaded...

[elma]

Thanks jim, I've got my eye on a set of Citroen boxed Bosch ones. I'll change them at work so I have an airline handy. Just waiting for the 15th for some pay before I order the bits.

[lexi]

I put the super duper plugs into the Vel Satis. They last about 80k. Iridium. If the Xantia V6 were produced today, that is what they would use.
Even the little Jazz has those plugs.

[elma]

I'm not into iridium, they perform less well but last longer. Personally I'd rather change them regularly and have a better drive.

[CitroJim]

I once used iridium plugs in a TCT XM running LPG and in that application they did seem to bring forth a bit of an overall improvement when running on LPG but given the cost it was pretty much neutral. One area where they do seem to help is starting and on Sian's Pixo they seem to be essential for quick and reliable cold starting... The Pixo ones are eyewateringly expensive. Good job it only needs three!!

I must see what the C1 uses...

[elma]

Blooming v6 is a v5.5 now. It's been running alternately on 5 then 6 cylinders today. Interestingly I looked up iridium's for the Scenic (it's due plugs too) Renault actually have forbidden them in the Scenic which seems weird as it's the sort of car I would put them in.

[Mandrake]

Personally if you are having misfiring problems and plan to change the rear bank spark plugs anyway I would change the rear bank spark plug cassette at the same time.

The wires break internally where they come around the sharp bend at the back corner of the manifold causing intermittent misfiring. I've had to replace the cassette in both my V6's for the same reason.

The best place to buy them seems to be mister-auto.co.uk - last time I checked they were £45. I would tend to replace this before the coil pack because its a lot cheaper than a coil pack and it requires the manifold removing to change it so it makes sense to do it with the spark plugs whereas the coil pack is an easy 10 minute job to change should it be neccessary later.

A nearly 20 year old car is going to have worn out spark plug leads and it's very likely that it's still on the originals.

[lexi]

I'm not into iridium, they perform less well but last longer. Personally I'd rather change them regularly and have a better drive.

In actual fact James, I got no benefit from my fit and forget plugs as I sold the car, so new owner scored. If you can get a deal and don't mind fitting then the copper are probably best bet . The Vel was like the Scenic.........engine tucked under scuttle.

[xantia_v6]

If you splashed any water around the top of the engine while doing the coolant change, there is a fair chance that your misfire is due to water finding its way under the manifold or top cover and drowning one of the spark plugs in its well.

I have never had the coil pack or plug leads fail in about 230,000 miles of ES9 motoring in 5 cars.

[CitroJim]

I have never had the coil pack or plug leads fail in about 230,000 miles of ES9 motoring in 5 cars.

I have... It stranded me and I needed recovery home from Somerset... Coil was fine cold but broke down when hot...