Rough / Low Idle

[arejayesss]

Hello all! Thank you so much for providing this forum, it's great. This is my first post. I just traded in my 99 Grand Marquis Ls (2 previous Grand Marquis Wagons under my belt '85 and '91) last week for an 03 Black Marauder with 20,956 mileage!! I still can't believe I found it. I have wanted a MM for a while now. Of course, when I went to the dealer I had only planned on looking at it, not coming home with it. I'm sure no one can relate to this, but, I was so taken aback by it's beauty that I didn't really inspect the car as well as I should of. Anyway, to make a short story long, I have noticed a low idle RPM of about 500-700, and in addition to that the idle seems kind of rough. I can't really explain it, but I will be sitting at a stop light and I can feel little 'bumpity' in the idle. And also, performance wise, it seems a little restricted. I do not know very much about cars, so any help / advice would be great! To my knowledge, there have been no mods to the car (dealer didn't know of any) Thanks in advance!!! rjs

[Zack]

The rpm range is fine.
I recommend driving it hard for a while combined with a Seafoam treatment.
The last owner might have babied it and developed a carbon buildup on the piston tops and valves.

Good luck with it!

[arejayesss]

You know what, I think the original owner did baby it. The engine compartment is spotless, as well as the rest of the car. I put in a can of Seafoam tuesday night, and have not noticed any differences yet. Maybe it takes a little longer to work?? I have already begun your first recommendation!!!! (How can you not?) Thanks for the reply Zack

[Stranger in the Black Sedan]

The idle will be a little "bumpity" because of the cams in the engine, it's probably normal. As far as performance goes, these cars stock have brisk acceleration for their size, but are certainly not outright fast.

[arejayesss]

Are there any simple things I can do to help with performance, I am already using premium fuel and running synthetic motor oil. Also, the original owner had put in a K&N air filter. Better spark plugs? Cold air intake? Thanks again for your help.

[Stranger in the Black Sedan]

Bascially the whole point of this message board is to improve the performance and looks of the Marauder. I'd recommend sitting back, relaxing, and reading up. A lot of people have a lot of different approaches. Most guys are doing PCM tunes and gear swaps as early on modifications.

[arejayesss]

Quote "As far as performance goes, these cars stock have brisk acceleration for their size, but are certainly not outright fast."

Well, outside of that fact, it just seems like there is something kind of restricted or not performing fully. I don't know, maybe it is normal. Would one of the computer chip upgrades be helpful from Reinhart or other company? I don't know anything about these computer chips.

[KillJoy]

Quote "As far as performance goes, these cars stock have brisk acceleration for their size, but are certainly not outright fast."

Well, outside of that fact, it just seems like there is something kind of restricted or not performing fully. I don't know, maybe it is normal. Would one of the computer chip upgrades be helpful from Reinhart or other company? I don't know anything about these computer chips.

Yup!

An XCal2 from several of the Vendors here would work very well for you.

Reinhart's or Lidio's Tunes will REALLY wake the car up!

Just pick one, and enjoy!!!

KillJoy

[gohogs]

Some owners reported problems with the IAC (Idle Air Controller), some even carry a spare. It's an easy replacement (two bolts and a push on by-pass tube). Not expensive to carry a spare. I have have no problem with my MM, but have with my 2000 CVPI, and it does give you a rough surging idle.

[Local Boy]

Congratulations on a great find! You metioned that you have a K&N filter. Here's your problem... The K&N filter is a "oiled" filter...meaning that the filter element has oil applied to it to improve its filtering. This is a good and bad thing...in the sense that it does improve its filtering qualities:However, it also deposits the "oil" on to the MAF sensor - resulting in a rough idle and less than aceptable performance. Get a can of MAF Cleaner (specifically made for MAF sensors - NO RESIDUE) and clean your MAF. It's really easy! 10 minutes and your done! Hope this helps - ALOHA

BTW: Regarding the seafoam... You need to use up the entire tank to purge the fuel system of the sea foam before you expect to "feel" the performance come back...Seafoam is a cleaner and does not combust at the same rate as good fuel.

[Stranger in the Black Sedan]

Yeah the K&Ns get overoiled sometimes, didn't think of that. I would just use a regular paper air filter.

[arejayesss]

Update: Car seems much 'healthier' I have done several things since this original post. I put in a can of seafoam treatment, installed a K&N CAI. While I had my intake apart I cleaned my MAF sensor, and also used a bottle of the fuel injector cleaner. I have definitely noticed a difference in the last day since I put in the CAI and cleaned the MAF sensor. I have also been running it hard to clean up any deposits on the cams. I don't know if I can attribute it to any one of these things, but something worked!! Thank you so much for your help. rjs

[96DiamondVIII]

My car has showed an occasional rough/shuddery idle at stoplights (happened twice today, which is what made me think of it), and come to think of it, I did recently clean/re-oil my K&N and may have put it on a bit thick. Is there any particular brand to look for, or do I just head down to advance and ask for MAF cleaner? Where exactly is the sensor itself, and are there any removal considerations? Thanks in avance...

[arejayesss]

Yeah, its very simple. Just ask for MAF cleaner. The can says MAF cleaner. I have a harder time finding the right household cleaners for certain surfaces at home!!!! The MAF sensor will be located in the upper portion of your intake tube, right before the air gets sucked into the engine. Once you take apart your intake tube at that joint, you will see a little 'thingy' sticking down inside the tube. THATS the MAF sensor. Spray it down, wait a little for dry. done.

[mtenderenda]

Last night, i took the car out...
The first trip car was fine...It was alittle rough, still it was ok..
The second trip out, it was rough and error codes came up...There was 6 of them..I'll check them later...