Contour Enthusiasts Group Archives Forums General Troubleshooting DPFE Problem?

My '98 (68k miles)Duratec has been making a whooshing sound from under the hood during hard acceleration. I began to notice it when the outside temperature started to dip below about 15F. It seems to coincide with the activation of the IMRC above about 3000 RPM but only when the engine is under heavy load. It does not happen when the engine is gunned while in neutral. Fuel economy has dropped a bit but this might have more to do with the average temperature being about 10F over the last week or so.


I have looked for loose hoses all over the engine compartment and have found nothing.

I have read a bit about the DPFE in this forum, but several things are not clear to me.

1) Where is the DPFE (if so equipped)located on a '98?
2) Will a DPFE problem generate a CEL?
3) Does the outside temperature really have anything to do with it, or is it my imagination?
4) If the worst has happened and my precats have failed, what do I tell my LM service manager to persuade him to investigate the precats in the absence of a CEL? I assume that I have a little time to get these replaced before the 7/70 limit.

Any help would be greatly appreciated. Thanks.

The DPFE should be located on the firewall. The part can give some weird failures, but will cause a code in most (if not all) cases.

You aren't describing symptoms that would indicate a failed DPFE, but changing it wouldn't be a waste of the $$$ if you plan on keeping the vehicle.

Failed cats should also cause a code. I can't see how they would cause the sound either though.

I can't think of what would cause the 'wooshing' sound. Seems interesting that it doesn't happen in gear. Maybe it could be trans related in some way, but I am at a loss here.

I will scan for codes in spite of no CEL. The car was running very well up until the cold weather hit here in MA, so I agree that the precats are probably OK. In fact, in the fall I took the car on an extended highway trip and got over 30 MPG. Can the precats fail suddenly, or is it gradual? It definitely coincides with IMRC operation under heavy load , though. Do I have an intake manifold gasket leak? I would think that such a leak might cause problems at idle. The car idles just fine. My guess is that the cold weather has caused some plastic or rubber part to crack. I'll keep looking. It would be nice to completely eliminate the precats as a problem before my emission warranty expires in a couple of months.

Thanks for the reply. Did I read that right? 148K miles on your Duratec? You must have some stories to tell.

I thought of a vacuum leak also, but I would think you would get lean or rich code, and it would show up at idle.

I still keep coming back to the fact that it only happens in gear. Maybe there is a vacuum line attached to the transmission that is leaking only when the drive train is in certain positions. I'm grasping here, but I'd at least look for vacuum/transmission related things. One thing to check is that your dip stick for the transmission is pushed all the way in (assuming you have a ATX).

Yep, I have almost 149,000 now. Pretty much uneventful - I've been blessed to have such a reliable vehicle but I believe that proper maintenance schedules plays a big part.

Well...I have an MTX with a V6. I have had cars with vacuum leaks before and none were this loud. If I had to compare the sound to something, the closest thing would be an uncapped air hose at the gas station that one uses to fill tires. It's that loud. I can easily hear it over the usual engine sounds during hard acceleration.

I'll keep looking. Thanks for the help.

DPFE is mounted on the engine, just below the EGR valve on the V-6 engine. It's a small rectagular box (either metal or plastic) with a plug-in connector and 2 hoses

Thanks. I'll take a look at it tonight.

I believe that I have experienced moosing in the past. It always seemed to happen when the ambient temperature was very high in the summertime. It sounded like a very low frequency tone and only at idle. What I am experiencing now is definitely the sound of alot of air either escaping from or being blown out of an opening at high engine speed and load.

Does the moosing problem manifest itself differently in cold weather? I use a K&N filter in the stock Mystique V-6 airbox. Red herring or important part of the puzzle?

I definitely do not have a CEL, but will scan for codes anyway.

Had a similar sound coming out of my 98 2.5.Sounded like air whooshing out at high rpm,was louder than the engine.Took it in they found,a hose that had come off the cat,or so they said.Anyways turned out that it blew off two days later, was traced to a plugged rear precat.Had the cat replaced under warranty thank god,and has been fine since.
Good Luck.