I'm puzzeld - spark plugs for Xantia Mk2

[atr]

Hi
After the problem that I had with the hidrostatic locking of my Xantia's RFV engine (2lit. 16v, 2001) I've changed the spark plugs. the ones that were fitted are EYQUEM rfc42lz2e and it was running smoothly. the new ones that I've purchased are Denso K20TXR and I'm facing phenomena
that seems like lack of power and sometimes it seems like only three cylinders are functioning. yesterday was the worst - it was like I've described befoe plus there was a cloud of smoke of oil that was emitted from the engine (I couldn't see exactly from where since it was at night ) and today I've noticed that the level of the engine oil decreased.
your comments and opinion will be a great help.

[addo]

I'd suggest a compression test on all four cylinders first, if that is OK then look at the coil dwell times on Lexia - the pair of coils should have near identical dwells.

[Mandrake]

I wouldn't place too much faith in small differences in dwell times on the Lexia, after having been down that road replacing a coil pack that turned out not to be faulty with a brand new one, with both old and new coil packs showing different mismatches on the Lexia. My problem turned out to be a damaged spark plug lead that was sparking to the chassis through a hole in the insulation and fixing it fixed the misfire but did not change the difference in the dwell readings one iota!

Given that the car suffered from hydrostatic locking of the pistons due to water intake you should be looking for potential damage that has been caused by that. It's highly unlikely there is anything wrong with one of the new spark plugs, as long as they're a compatible type they're not going to cause you problems. The cloud of smoke is suspicious too, a misfire due to a spark plug is not going to cause that. Unfortunately my guess is there is mechanical damage that occurred at the time the water locked the engine, but finding it could be difficult. Certainly do the compression test as a starting point.

[citronut]

as you say it was running smoothly before fitting the new plugs did you check the gap of the new plugs, maybe one has no gap (closed up ) possibly droped at some point

[Mandrake]

The old spark plugs were removed to eject the water locking the cylinders, (discussed in another thread) but were the old plugs put back in and running well after this happened ?

If so, why not just put the old ones back in, a bit of water won't have damaged them.

If not and the old plugs were removed, the water was expelled from the cylinders and the new plugs were put in its more likely there is un-diagnosed damage to the engine as we haven't seen it running afterwards with the original plugs.

So to clear things up, was the car running smoothly on the old spark plugs AFTER the hydrolocking incident ?

[atr]

No. after the water was expelled from the engine, I've replaced the spark plugs with the new ones (denso K20TXR). what I reffered to that it was running smooth - it was prior to the "incident" as you called it.

[Mandrake]

That's what I thought. We don't know if there is a problem with the type of the new spark plugs or whether damage was done to the engine. If you still have the original plugs and they look in usable condition as a quick test I would refit them and see whether the symptoms stay or go away...

[atr]

I have them and I'll try to put them back tomorrow and then I'll report what the outcome is. in the meantime I'll try to find &download the lexia software (I've lost the disk that was supplied with the cable).
Thanx.

[citronut]

No. after the water was expelled from the engine, I've replaced the spark plugs with the new ones (denso K20TXR). what I reffered to that it was running smooth - it was prior to the "incident" as you called it.

in that case i suspect engine damage,

did you crank the engine over with the plugs out to expel the water before fitting the new plugs

[Mandrake]

Yes he did. See this thread:

http://www.frenchcarforum.co.uk/forum/v ... =3&t=42843" onclick="window.open(this.href);return false;

[atr]

Update.
I've replaced yesterday the cover plate that carries the coils and the spark plug connectors, as was mentined by Addo&Mandrake. didn't replaced the plugs - left the new ones. so far seems O.K. I'll see what will be in a day or two.