I have a 2005 Ford Focus and it has done 91 thousand miles to date. Only this year have I had a problem with cylinder 4 misfiring. The spark plug well/valley (as i've seen it been called) is full of water, mainly over cylinder 4. I've had the core plugs replaced and coolant topped up and after the spark plugs have been dried out. After a month of being dry they will fill with water somehow and causes cylinder 4 to misfire! This tends to happen a lot in low revs when applying sharp or sharpish acceleration. Any tips on where the water maybe coming from as the coil leads seem to have a good seal. No coolant has leaked either.
Check for leaks on the valve cover gasket.
I will take a look at this. Thank you for the recommendation
When the core plugs were replaced so was valve cover gasket. So the seal should be good, only cylinders 3 and 4 are affected badly by this. I've had a look at the spark plugs just now and they seem a little wet with pure water, no coolant, it hasn't rained where I live for a week. Core plug look rusted again and spark plugs not in healthy condition. Any ideas on where else the leak could be into the spark plug wells?
@kp is there a possibility that exhaust gases could leak from the exhaust manifold back into the spark plug area (combustion area) and condense back to water? As it has been dry all week and my spark plugs are still getting wet.
Possibly.
definitely not. water can't condense on a hot engine.
Okay, I think the only possibility left would is a crack or a leak of the gasket or on one of the cylinder heads. I'm guessing its a small amount of coolant leaking into the plugs causing the misfire. Plus the engine head cover is all rusted from the consistent water build up which I think has chronically damaged the engine health
Very strange. you mean clear water, or colored engine coolant?
This has happened for the past 5 months and i'd say once a month it has been cleaned out. I saw the fluid last time and it looked like clear water. Coolant level still at max. As mentioned previously, core plugs replaced as we thought this was the issue. Plug leads are rusty inside. Top of the engine has a greasy feel to it and looks oily/greasy rather than dry dirt. I've been told on my model focus that the jet washers for the front windscreen can leak and they are directly above the plug leads. But I can't see any sign there. Or on the scuttle boards.
ahhhh. well lift the hood up a bit, peek under, and run your squirters
I've checked the squirters just now. They have a solid seal. No water leaking through them or from the ejt hoses themselves. Just checked the engine bay and on top of the rocker covers there is a greasy texture and it looks like the throttle rail has a brown substance on. Not sure if this is hinting towards a leak somewhere else and its not water in the engine.
some photos might help