miss under light load 3.0 dohc sable

[TheB2B]

My Taurus had the exact same issue, replaced the spark plugs, same problem. Replaced the coil packs on all six cylinders problem solved. Same engine, same year but a Ford not a Mercury. Purchased the coil packs on line for around 165 with shipping.

[behlinla]

Yes, it still sounds like you have one or more weak coils. The engine is under greater load when in overdrive, so you need more spark energy. The cracks can be very tiny, so look on all sides of the coil. Or ohm test them all.

[cvsable]

Ok, thanks that's actually great news, coils are cheaper than tranny's, lol, my gut feeling is usually right and it feels like an ignition miss, the trans fluid is up and clear, I must be just over thinking this so I will inspect the rear coils and do the plugs Thursday and let you know, no comments on the plugs though, any thoughts on the NGK?

[behlinla]

Yup, make sure you get to all the plugs in the back. Sometimes people skip them 'cause they're lazy.

NGK plugs are okay for Al DOHC heads these days. NGK might even make some plugs for Ford. I recommend Autolite, Motorcraft, or NGK plugs.

[cvsable]

thanks, lastly, the plugs in it now as mentioned earlier are Iridium, was this stock for this engine, or were they upgraded from standard or platinum?

[Breeves002]

The original plugs were double platinum, and I would stick to them if you can. However I've seen people use Iridium with no problems. If you want the plugs to last 100k miles though, buy double plats.

[cvsable]

ok thanks

[sheila]

Iridiums should last longer yet.

[cvsable]

WHOO HOO!!! SUCESS!, well thanks for the help and for anyone following this thread, the problem is gone, what I did...replaced all six plugs with double platinum Autolite, (the old NGK's were worn right out with lots of wear and wide open gap), many people mentioned looking for cracks in the coils, #1 cly's coil had a small hairline crack right across the top but all coils ohm'd out the same as the one new one I purchased and had on hand for the repair, so I did replace that coil anyway, I cleaned the throttle body with proper spray and checked all vacuum hoses for leaks, (none found), went for a road test and all is good!, It was also recommended to change the pcv valve while the uim was off but where the h... is it?, I thought maybe at the d/s rear valve cover on the side there is a plastic fitting there but it didnt seem to want to come without breaking, some threads said dont bother, anyway maybe someone knows?, lastly for anyone doing this for the first time there is lots of short cuts that can be done to save time, I unbolted the uim and disconnected the coolant hose under the T/B as well as the vacuum hose, (1/2 inch or so) underneath as well, then a few other electrical and vacuum disconnects, then when the manifold was unbolted just swung it out over the front valve cover while working on the rear plugs, I did remove the egr and replaced one of the gaskets only because I had one but they and all other gaskets were ok to re-use, everything went rather smooth,thanks again for the help, I have another totally seperate issue to ask about but I will start another thread as it is a different topic

[behlinla]

Glad you got it fixed! Sounds like you did everything right.

04 Duratec, PCV valve, where is it??