03 Crown Vic tranny slipping maybe? I can't diagnose; any ideas?

There were lots of complaints of transmission "shudder" in some of the Fords using that transmission. not sure of which years but I think it included the 03's. The cure if often as simple as a transmission fluid change or fluid flush. I think it has to do with the lock up clutch in the torque converter. They are designed to sometimes run at less then 100% locked and I think that, combined with transmission fluid that isn't up to snuff, causes the thing to shudder. There is also a special transmission additive (can't recall the name) that many people have added that is said to help a lot. Do a google on "ford transmission shudder" and you'll probably find more stuff then you can find time to read.

The problem is usually trans torque converter shudder or engine misfire. The misfire can be caused by a bad plug boot. I believe you can buy them separately nowadays. That would be relatively cheap to ensure water is not getting in there causing a short.

The converter problem can usually be fixed with a fluid change. Many people like the flush method. I still like the drain and fill method where the pan is removed to drain the sump and change the filter. The torque converter should have a drain plug that is accessed thru the opening in the bottom of the bell housing after removing the rubber plug. The engine will need to be turned by hand to align the drain with the opening. NOTE: there are no external adjustments for this trans other than selector and nuetral switch which are both rarely required after installation. The shudder usually goes away soon after the fluid is replaced. Either way, a fluid change and service is still necessary and more expensive than ever - still one of the cheapest things you can do for your trans. If you have never had it serviced, it is probably due even if the COP boots fix your problem.

You might also note that the OBD2 powertrain management system on your car can and usually does record and flag engine misfire with cylinder identification. It may be that you need to subject it to a better scanner than those at the local parts store for a complete diagnostic. Converter shudder is not normally flagged by the ECM as it usually does not provide enough converter slippage to set the code. If it did, there would be more vehicles in for repair than you could shake a stick at. You may simply be at the annoying stage.

Lugnut

Thanks guys. I will go with that and let you know what I find out.

Have you tried tightening the transmission nuts? Sometimes the transmission nuts come loose, which results in the transmission fluid leaking out. The leaking fluid gets into the spark plugs and makes them misfire.

Maybe I missed where Ford started putting transmissions on top of the engine, but I just can't imagine how leaking transmission fluid could possibly get into the spark plugs.

If it was "leaking" through a perforated diaphram of a vacuum modulator, fluid could get to the plugs.

With that particular engine/transmission when certain transmission nuts become loose hydraulic oil can sometimes be ejected at high pressure. The end result is an intermittent misting of the entire engine compartment.

The misted oil droplets are naturally attracted to the high tension leads which results in the high tension leads wicking up the oil and becoming contaminated.

In the case of multiple loose transmission nuts, oil can be ejected directly into the fan which in turn flings it onto the high tension leads.

It is also possible to detect loose transmission nuts by using the dye test.

No vacuum anything on that trans

Lugnut

Whatever you're smoking is better than any I've had.

Lugnut

How about you check to see if there are any software updates for the ECU and the tranny computer? Maybe there is a update to address this shudder. Otherwise, maybe it is the summerfuel, lasttime youdid a fuel system cleaning, tuneup, what is the running temperature of the motor,altitude of when you start going uphill?