Hi there

Well it miss-fired last week and never again since until tonight. I went out in the car at lunch time when it wad dry and she drove fine. Yet tonight in the wet very slight miss-firing, sounds almost like a crackle and most noticeable between 3500-4500rpm and more noticeable if one holds light throttle at 3500rpm and then accelerates it's noticeable more so, particular in 2nd gear.

So on both occasions this has happened it has been raining which can't be a coincidence really.

Surely if the coil packs were failing this miss-fire would always be present?


Could water getting in through the washer jet seals cause this?

But surely if water was getting in would it not dry out once engine was unto full temperature? Tonight the car was still miss firing some 30 minutes later and I'd have thought any water that could have dripped down from washer jets would be dried out, or would moisture/water not dry out quite so quick as I'm thinking.

It's also notvthe DSC system as I shut it off to rule that out.

Any advice or things to check as I really don't want to go changing the coil packs at a cost of nearly £200 if they won't solve it and it's just a water/moisture issue.


P.S. Car is an 2000 3.0 V6 manual S-Type

 

May be coils or oil in coil wells. Lincoln LS used the same coils which are half the price. Check for moisture in trunk too.

 

Read the codes and post them. Do you get restricted performance or failsafe indications?

 

No error codes that I can read and I don't get any restrictions or failsafe indications.

It was not raining this morning, though it had been raining through the night.

So I started the car and then lift the hood and lots of steam came up and the lining around the washer jets was wet so I think water is getting in through the washer jets or possibly around that area and dripping down onto engine area which I suppose could definetely cause such issues and as it only seems to be when raining would maybe prove this theory?

 

There is a design flaw allowing water to seep around the windshiels cowl down into rear of engine.

 

Probably a failing coil. Mine did that for over a year before an error code showed up.

 

Definitely check there's no water/oil/contamination in the plug wells - fairly common cause of misfires. Yes it could be coming from the washer jets but also could be getting in past the cowl as has been posted.

I think the car counts misfires per cylinder but a typical OBD tool won't report those counts. You'll only get a code if the counts are bad enough to flag a code. In any case the PCM needs to have gone CL (closed loop) - which any OBD tool which does live data should be able to report.

 

No codes! If water is getting into and on the engine it might be traveling into the cylinder plug area causing it to stumble. Water and condensation is not a good thing. I would also suggest removing the plug for the throttle body and clean and dry the contacts, you can use CRC contact cleaner and a little di-electric paste on the contacts. Make sure the contacts are clean and tight when you put it together and see how it goes. Had a similar problem and it worked for me.

 

Hi there

Its the lower window rubber seal / scuttle/cowl basically when it rains water is running down the windscreen and straight onto back of engine.

Fixed for now with silicone but shall look at buying a new scuttle and lower winscreen rubber.

Thanks guys.