Best way to clean IM?

[Fett]

What is the best way of cleaning the IM? Is using the spray that you use while the engine is running just as effective as using a rag and cleaner and doing it by hand?

I have some spare time this weekend, and I want to go ahead and do some good cleaning in the engine. I haven't done a through cleaning yet.

[Andy]

I want to do it, know it needs to be done, but am afraid to try to take the UIM off. I just dont want to fudge something up.
I've tried the spray, seemes to work a bit. Notice a little blip in performance and pickup, but I imagine there is no substitute for actually getting in there and cleaning.

[ZERO]

its a pretty big pain to take it off, actually the main thing is the EGR gasket.. i dropped 2 of em in my frickin engine bay! got one out but the other is idunno where

[pgtatx]

The upper IM shouldn't be too tough to get off. But that'll be the best way to clean it. I soaked min in the most powerful cleaner I could find. then fluched it out with water, and soaked it again...I also cleaned my lower while I was at it...

[mello88]

Probably the best way is to remove your stock unit and replace it with a shiny new clean SVT manny .

On my truck, I would yank the upper and carb cleaner/soap+water it, then dry it all off. Same for the TB, but I think some newer (ours?) TBs have special (teflon-like) coatings on the inside that are supposed to reduce the amount of crud that builds up. Because of these coatings, you're not supposed to use very abrasive/caustic cleaners on them.

Pulling the upper shouldn't be that big of a problem either. The first time is the hardest . Many others have said that they can swap their uppers in under 20 minutes or so (after doing it xxx amount of times). I don't doubt that for a minute -- I had my truck upper off in about 10 minutes after I got the hang of it... Just be sure to give yourself enough time to get it off/back on (IE, don't remove it at 7:00am when you have to be at work at 8am . Give yourself enough time and make sure you've got the right tools.

Sorry this doesn't have any specific answers, but it just might be classified as 'useful' information.

[katnyp]

I would take the thing off and clean it. You know you're getting it clean, and can see the results. The only way to be positive about how well spraying the running engine works, is to take the upper off to see how dirty it is, put it back on, spray clean, then take it off again.

A number of people have claimed good butt dyno results from doing it the easy way, so I'm sure it works somewhat.

This is just an educated guess, but I don't see how the secondaries would get very clean unless you take the IM off. 70% or more of the grime is in the secondaries, and if you spray the running engine, the secondary intake butterflies are closed, so very little air and cleaner is going to reach the dirtier areas of the intake tract. (unless you're Bnoon1 and don't have butterflies)

[MaStaMooN]

Yea, I believe removing it is the only way to get it really clean. I cleaned mine recently by spraying a good amount of carb/tb cleaner in it, using a tooth brush/bottle brush to clean out the ports... Letting the chemicals sit in there for alittle bit, then spraying it out with water. Then repeat again to make sure all the gunk is out. You will be amazed by the amount of crap that comes flowing out. And to do the lower, I just sprayed a rag with the cleaner, and scrubbed the ports and butterflies with it... Just spray it down, put your finger in the rag and scrub. The only way to get it totally clean is to take it off.

BTW, to keep your secondary ports cleaner, keep them cracked... You can adjust them with a screw on the lower... By keeping air moving through the ports, all the gunk doesnt build up on them. I learned this by having mine stuck open for 6 months... My lower was as clean as the day I put it in.

[PuckPuck]

not so long ago i cleaned my upper and lower.... (about 2 months ago)... last week i took the upper and lower off again just to be disapointed by how gunked up the secondaries were... follow mastamoon's advice... i have mine cracked also (2 full turns on the screw)... the power transition feels smoother although i don't notice any type of power loss/gain... and i would bet that this will help greatly in keeping the secondaries clean.... the other problem i can see is the PCV valve... the ideal way to do this is to get a collecting cannister on the hose to collect the oils but still allow the pressures to vent

[mello88]

Reading and thinking about this again -- the REAL reason why the TB/UIM/secondaries get coated with oily crud is because of the PCV system... My understanding (pretty sure our car works the same) is like this: the engine needs to be vented of oil/gasoline vapors. This is done through a hose that is connected to one/both of the heads. On the other end of this hose is some arbitrary part of the induction system -- usually the throttle body. When there is vaccum present in the manny, the oil/gas vapors are sucked out of the crankcase/head and into the intake stream. These vapors are very hot when they leave the engine, and sucking them through the UIM/TB causes them to cool off and affix themselves as crudy solids to the valves/TB/UIM.

Prolly the best way to eliminate this problem would be to semi-eliminate the PCV system -- by installing a K&N style breather assembly. This would allow the vapors to still be vented, although they would not be sucked into the engine again. They would be permitted to exhaust to the atmosphere. I don't know if this has been done on our engines yet, but it wouldn't surprise me if it has. Any thoughts on this?

[MaStaMooN]

WDOMKR was selling PCV mods that first pulled them together then ran into a K&N filter... The only problem with this was it would fill up with oil quickly and clog.. (i had mine on for like 5 days and it was already oily... Also, Im pretty sure in order for it to vent correctly, there needs to be a vacuum.. But I believe Craig has had his hooked up to 2 breather filters for awhile with no ill affects??

Im leaving mine hooked up.. With cracked secondaries, you should have alot less build up, Ill go with this untill something else is figured out.