I would NOT do this and it's not recommended by anyone I know with an M90- the teflon coated rotors in the blower do not play well with SeaFoam. You will soak them with SeaFoam if you introduce it via the brake booster cable.

The vacuum T right below the supercharger snout is what's generally recommended and what I use.

Regarding cleaning your supercharger, throttle body, and MAF:

- Do not "clean" your supercharger. It's better the way it is, and you'll probably damage the coating on the rotors if you try to clean it. With a little build up the rotors actually seal better.

- Cleaning your throttle body is a great idea. Remove the MAF, then remove the throttle body from the vehicle and spray it down with throttle body cleaner, wipe off, and repeat until it's clean. If it's very dirty now, you will notice an increase in power and throttle response.

- Cleaning your MAF sensor is an even better idea. Remove it from the vehicle, than clean it with a dedicated MAF sensor cleaning aerosol (they sell this an Advance/Autozone/waddever). Make sure you use a dedicated MAF cleaner. Do not touch the MAF wires with your fingers/any tools/any surface. Only use the spray cleaner on the MAF wires. Do NOT try to wipe the wires with a cloth or towel. Be careful when cleaning it and do NOT use a petroleum product on it. You will notice the car running better with a clean MAF, and it's amazing how dirty they get.

Regarding descreening your throttle body- I descreened the throttle body on my Regal GSE (same engine as your Monte)- didn't notice any difference at all. Some folks report problems due to descreening due to the MAF getting improper readings- I haven't experienced this, but due to the VERY minimal if any gains I probably wouldn't do it again.

Regarding porting your throttle body- you will experience a gain in power by porting your throttle body or buying a ported throttle body. That M90 is hungry; the more you feed it, the more it performs.

 

Excellent advice my friend. Thank you!!

 

No problem! Let us know how it runs after your maintenance.

Then all you'll need is a 3.5 pulley and 3" downpipe and it'll be a whole new beast.

 

I wouldn't bother unless you have a tuner- the results are awfully mixed with just doing it and not adjusting for it. It's also different if you have an aftermarket intake, and can get a nice smooth section before the TB so its not so turbulent coming in.

Honestly, if your air filter is missing stuff big enough that the big holed MAF screen catches- then you've got a problem.


I totally agree, although that LIM hose won't clean very much. There is no really great way to do this on an L67 IMO. The brake booster hole is great for cleaning out a bunch of gunk- it's pretty much right above the EGR inlet. But as mentioned- you really don't want to clean the stuff off the rotors. That built up gunk on there is making a slightly tighter seal- and stripping it off will make you lose efficiency and boost.

The problem with the LIM nipple is its all the way at one end of the LIM- so I really doubt its getting much to the two cylinders on the opposite end of the engine, and you're only cleaning from the LIM down- this won't clean the SC outlet or inlet, or behind the TB at all.

 

Hmm, point well taken regarding uneven distribution of SeaFoam to the cylinders. I do think it still helps though. Regarding cleaning the bottom end only- that's the most important area to de-carbon on our L67s, since carbon build up increases effective compression ratio (and theremore makes the mill even more knock-prone).