Exhaust

[Richard]

I recently had the exhaust centre section and back box replaced on my Williams 2.  Both have been replaced before.  I was surprised to find that the back box was a Clio 16V part rather than a Williams part - narrower tail pipe.  On checking it was the correct part number for the Williams.  Are Renault now supplying the same back box for both the 16V and the Williams?

[Rob.]

I have never heard of pipe thickness differences on 16v and williams exhausts. What exactly do you mean?

The differences in exhausts comes from the different catalytic converters and the different hanger types on the two cars.

[Richard]

Photos are the best way to see the difference - I have a PDF I sent to Renault.  Where can I send it/post it so you can see the difference?  The part fits the car perfectly - it's only the diameter of the pipe leaving the rear silencer box that's different.

[Rob.]

What is the diameter of the old and new?

[Richard]

I measured the circumference - it's easier.  On my old Williams exhaust the pipe leaving the rear silencer has a circumference of 160 mm, leading into the chromed section with a circumference of 225 mm.  On the new exhaust fitted to the car, the pipe leaving the rear silencer has a circumference of 140 mm.  The chromed section is 225 mm, as on the original.

I'm not too bothered about the difference - I think the silencer is a 16V part and the 16V revved higher than the Williams.  It's just odd that the part number is correct but it's a differerent part.  The frustrating thing is I can't get any sensible comment out of Renault.  Aftermarket exhausts are obviously an option, though they generally don't fit as well. 

The car is going very well.  At the same time as I had the exhaust replaced I had the timing belt and multibelt changed.  I've got a squeak from the power steering on full lock, which I think has been diagnosed before as a slighlty loose multibelt (or oil on the pullies).

I was interested in comments about the oil filter.  I've noticed that my oil pressure doesn't seem as high as when I first had the car (I've owned it since it was new), though there's apparently no fault.  Seems it's the Renault oil filter.  I'm using Mobil 1 fully synthetic oil.

[Rob.]

What is the diameter / circumference of the in pipe?

You wont get a sensible answer from Renault. There are probably only a hand ful of Renault employees in the whole country that know their arse from their elbow. You have to remember that Renault buys these exhausts from manufacturers in batches. The spec changes from batch to batch. I am 99% sure there is no difference between a 16v and williams exhaust except for the hangers, and the cat. I cant see why their would be a difference in the exit pipe on the back box, Renault simply do not go to that level of detail. If it drives ok, and looks ok, i wouldnt worry about it.

I will measure the circumference on my williams exhausts and my 16v exhaust, andposts the results up in a bit.

As for the oil filter, i have researched this extensively. Of course some of the drop may be due to engine wear. Do not discount this. However, Renault changed the williams filter, from a specific williams only item, to a now generic clio filter that also fits diesels, and other Renault cars. The new filter does not maintain as high engine oil pressure. You cannot get the old mann filter even from mann. I wrote to mann and they confirm the new filter is not the same filter pore size and the pressure relief valve is set at a different pressure.

The oil filter i found to be the best replacement was the champion f136 filter available from halfords. This is what i now use. With the new Renault filter i might have got 2.5 bar at 3k at 80 degrees, with the champion i get 3.5 at 3k at 80 degrees, which is book figure.

[Richard]

Harder to measure......but 160 mm circumference on both.