5.4 V8 has started to die at idle.

[SierraHawk]

This is a 2003 E350 SMB 4X4. It has 140,000 on the original engine, has run great up until now and uses less than a quart of oil in 3000 miles. We are doing a grand tour of the US this year. In the past 4 weeks the 5.4 has started to die at idle but only when the engine is hot. It dies more frequently when putting it into gear from park but will die at up to 50% of the stops we make in town (only when the eigine and outside temp are hot).

I haven't noticed any missed firing - spark plugs were changed at 100K. No color to the exhaust. Gas mileage seems to be a little worse but we are towing an Airstream trailer so it is hard to tell. The only change that I have made in the last two months is that I replaced the OME air intake filter with one from NAPA. Reason why is that the last dealer that charged me to replace the air filter when I had it in for a lube and oil change did not actually put in a new air filter - they just left the old air filter in place.

I burn Chevron when we are in the western US but we are now traveling in New England states. I periodically add Techron to prevent the injectors from choking off but, without tearing everything down, we will never know if it really helps.

We are now in Vermont and will be touring the East Coast for another two months. Are the NAPA air filters inadequate? Should I go back to using the Ford OME air filter? Can the idle be reset like on an old style carb or does it have to be adjusted through the computer? Is there any magic stuff that will fix the problem so that the SMB will get me back to Tucson by December?

Appreciate any suggestions.

Michael

[SteveInLA]

It may be an apples and oranges thing and may not even apply to a Ford engine, but my '78 Volkswagen van used to do the same thing periodically. The fix was to replace the engine temperature sensor, which in that engine was a $25.00 part and simple to swap out. With all the chips and sensors in today's engine, it just takes one misinterpretation of data to foul things up. Hopefully this steers you in a helpful direction.

Steve in L.A.

[dhally]

Many auto parts stores will lend you an engine computer analysis tool. It might give a code with a hint of the problem.

[Ford_6L_E350]

Ask around for a good dealership repair shop. I had a tow company tell me which dealer gave good service and which one to avoid. Auto parts stores should also know. They have the best equipment and knowledge to work on your van. Asking around, you may find that an independent shop in that area is the place to go. Ask more than one place for a reccomendation.

If the dealer that charged you for a new filter that wasn't installed, I'd go back and talk to them and either get my money back or let then know why they won't be getting any business from me or my friends. And I'd let the state Bureau of Auto Repairs know about it also.

Mike

[carringb]

Idle air control valve is dirty or sticking. You can pull it and try to clean it, but it likely needs replacement.

[SierraHawk]

To anyone who has a similar problem; it was the idle control valve. It is not cheap ($140) but replacing it was simple.