Confused S3 or S3c

[merky300]

Until this week I have been convinced my car is an S3 however following my recent post "Body On Advice Needed" it was mentioned that I had an earth point on the chassis which was thought only to be on the S3c chassis. I have now come to change the spark plugs for some NGK BCPR6-ES which have a flat washer fitting and found that the old plugs have a taper fitting with no washer, which I believe were fitted to the S3c.
Is there any sure fire way of telling if the car used to be fitted with cats and is am S3c?
Are the plugs interchangeable/is there any way of telling which plugs should be fitted?
Am I right in saying that the tapered plugs are only fitted to S3cs'.

The questions are coming thick and fast this week.

Thanks

Tony

[mep12345]

merky300 said:

Until this week I have been convinced my car is an S3 however following my recent post "Body On Advice Needed" it was mentioned that I had an earth point on the chassis which was thought only to be on the S3c chassis. I have now come to change the spark plugs for some NGK BCPR6-ES which have a flat washer fitting and found that the old plugs have a taper fitting with no washer, which I believe were fitted to the S3c.
Is there any sure fire way of telling if the car used to be fitted with cats and is am S3c?
Are the plugs interchangeable/is there any way of telling which plugs should be fitted?
Am I right in saying that the tapered plugs are only fitted to S3cs'.

The questions are coming thick and fast this week.

Thanks

Tony

Tony,

Don't get bogged down on the S3C comment wrt the earth, that was my guess from when the body off of my car happened over the winter. There is one sure fire way of telling the difference (listed in "the bible" and that is in the fuel system. If the car was an S3C then in the nearside boot where the filler pipe goes through you should have a "purge tank", which I understand filters the fumes when venting the fuel tank. On non cat cars the venting is done via a hole in the filler cap.

The Steve Heath Bible pages 67 and 68 refer. Steve comes up trumps again.

Mark

[tvrgit]

The S3C has lambda sensors in the exhaust manifolds. It has no air flow meters. It has a small black MAP sensor (about the size of a matchbox) on the bulkhead above the offside exhaust. It has a small purge valve on the nearside, a small metal cylinder plumbed in by two rubber hoses, it sits just above the windscreen washer bottle.

If your car has those, then it's an S3C. If it doesn't, it's not.

UNLESS (there's always a confusing "unless" eh?) somebody has changed the engine for a non-cat version, changed all of those ancillaries AND the ECU, at some point in the past.

At the end of all that, though, I'm not sure that evidence gives a definitive answer on what plugs to use - mine is an S3C and has always had flat washer plugs, so that's what I've used. Of course, a previous owner might have fitted the wrong plugs and I've just perpetuated that, but I checked the heads carefully at one point years ago and they don't look like tapered plug seats...

[merky300]

Thanks again for the advice, I'm quite sure again that it is an S3 and maybe the wrong plugs have been fitted. I've never owned a car which uses tapered plugs so I'm not to sure what the plug hole should look like. Mine look normal but do have a very slight maybe 1mm taper on the edge, which i'm not convinced hasn't been caused by the tapered plugs.

Tony

[sighck]

If you check on your cylinder heads there is a letter on one of the outlets (left side first cylnder). Letter F => plugs with washer, K => tapered plugs

/Hasse

[merky300]

Hi Hasse

Thanks for the info, if this is the "F" you refere to then the wrong plugs had been fitted previously.



Tony

[sighck]

Hi Tony,

Yes, thats the "F" i refere to.

/Hasse

[merky300]

Hasse

Many thanks for the advice, another dilemma solved.

Tony