Slightly off topic since this is about my 2008 Jeep 5.7 Hemi engine.
Took it to Dealer for 35000 mile service today and they recommended throttle body cleaning since they said it was dirty. Price $199.99, discounted from $249.99. Said they use a machine it takes 45 minutes and gets cleaned well and should increase gas milage by up to 2 MPG.
I went along with it since I made a snap decision while driving on the road and I want the Jeep running up to par for the winter. But, after googleing the procedure I am not even sure if the 5.7 is supposed to have cleaning done to it. I have cleaned throttle bodies on Mustang and GTO myself and cannot see why this must be so expensive and what machine do they use ? Anyway any input form the forum is good for me to hear.

BTW, I have three cars with the 5.7 engine so I am very curious. ( 2006 Charge , my wifes, 2008 Jeep Grand Cehrokee and my 09 B5 bleu 6 Spd )

thanks and Peace

 

I will be installing a catch can on my 5.7 to help limit this situation. I would think you could do just as good a job as the factory. Just spray heavy detergent carb cleaner through the system and clean intake as well.

 

The process cleans the intake track through a port on the intake. Cleaning the throttlebody on the car may introduce the harsh cleaner into the electronic parts namely the throttle position sensor and short it out. Also you could wash the carbon into the throttle plate shaft and that will cause excessive wear. The EFI cleaning process also cleans the injectors by running the engine on the actual "cleaner". But this is all just a guess.

 

The throttle body is up-stream of any of the blow-by goo that a catch can is supposed to catch, and so will not be affected by blow-by. On the other hand, if your air filter is an oily rag with holes in it (K&N, etc.), then your throttle body probably will need cleaning at some point.

 

I have a Mopar Cold Air Intake with blue filter, does not look oily at all. Is this a problem ?

 

I read on one of the other forums that the Mopar filters came in both flavors (oiled and/or dry). You'll have to rub it with your fingers or something to see if it's oiled. If it's dry, you can forget about it causing any grief for your throttle body or any sensors in the intake.

I only raised the issue of oiled filters because I had a bad experience with a K&N drop-in that I bought for another car (turbo 4-cylinder) I had. I bought it new, took it out of the package and installed it in place of the stock paper filter. It ran OK at first (no better or worse than the stock setup) but after a couple of weeks, the car started acting up. It was way down on power while at the same time the boost gage was showing the engine was getting much more boost than it ever had in the past. Investigation revealed two problems, both caused by the K&N filter. The first problem was that the oil in the filter had started to "gel" and was actually beginning to clog the filter. This caused a sufficient reduction in intake air flow to cause the boost gage to register "high" because it was comparing the pressure difference between the pressure just ahead of the throttle body (now artificially-reduced) to the pressure in the intake manifold (also now reduced, though not as much because of the turbo). Obviously, the over-all reduced air flow was the reason for the power loss, but a second problem showed up as well. During the investigation I disassembled the whole intake tract, back through the throttle body, and discovered that oil had been "leaching" out of the filter and been carried down stream, leaving a fine coating on everything. Unfortunately, this included the throttle body and the hot wire in the MAF sensor. I immediately replaced the K&N with a clean stock filter which helped a great deal, but the car wasn't completely normal again until I took it back apart and cleaned the oil off of everything. Ever since, I've been a big user/proponent of clean paper air filters and have never had another problem of any kind.

 

Trying NOT to hijack this thread but i couldn't help but wonder if K&N air filters are still all they're cracked up to be ie #1 air filter, etc. Ever since the 80's I've happily used K&N air filters on every car I've owned, never cleaned them or oiled them, just put them on and ran them. Never had any problems and I knew they were better then anything stock from the manufacturer. Heck sometimes I even forgot about them, life was good. But now many manufacturers are on to K&N and they produce their own quality air filters in the past 20+ years. And I'm sure filter technology has evolved a lot since the 80's although i couldn't tell how it has myself. So is K&N still the end all & be all when it comes to airfilters?
I ordered my my 2010 SRT8 Challenger with the Mopar factory performance air intake system. Although mine came with the Mopar blue filter my air pipe is not the silver pipe and it doesn't have the blue "Mopar" painted on it. Anyway I'm getting ready to install the Cervini's "ram air" PKG on my Challenger. The install kit came with everything including 2 K&N air filters. One is a direct replacement for the stock air filter while the other looks to me to be a breather of some sort. I was planning on swapping out the Mopar one for the K&N air filter but after reading all the way through this topic and its subsequent reply's I'm not so sure any more. Maybe dryer is better air filter wise but seeings how I never oiled any of my K&N filters to begin with, is this a problem? Any thoughts either way on this before I proceed with with the Cervini's ram air install?

Re: the catch can so I've been told is a necessary item that should be installed sooner vs later due to Mopars failure to address the issue during the engine design phase. As I understand it, it catches (contains) sludge build up and prevents its ingestion back into the engine. Our cars are new and still under warranty so this isn't an issue yet. However after several years and more miles along with expired warranties, this could be an issue. I think Moroso makes this part and it is sold by shopHEMI.com, FYI. Part costs $250, I think. Hope this helps you out some.

Re: throttle body cleaning by dealer - Although pricey, I think its a good thing assuming it cleans not only the throttle body but also the fuel injectors as well. And the dealership you went to did in fact knock a few bucks off the price of the job so what's not to like, IMHO?

 

Only throttle body cleaner we sell at Autozone is the STP brand.

 

I work at a dealer, the Mopar Fuel Cleaner kit comes in 3 parts:

One- a can that you dump in the tank
Two- Another can that you dump into a container that is pressurized with shop air and is run thru the fuel rail to clean the rail/injectors
Three- A spray can that is shot thru the Throttle body and cleans it and the intake valves.


We only charge 129.99 at our dealer for it.

Like i said, this kit is made by mopar and is approved on all chrysler gas engines

 

And we all know this is true because K&N tells us so... If you need to pass even more air than a clean stock filter, then the cheapest and easiest thing to do would be to toss the filter in the trash and run nothing at all. Of course, you wouldn't think of doing that. You want clean air going into your motor. That's why there's a filter in the first place. If a K&N filter is the same size as a stock filter and it passes more air, then it passes more dirt, too. You just have to decide whether you want clean air or more air...