Bama

How do you remove/replace the muffler in the throttle body for the IAC air supply? Does it pullout press in?

Knot 4 Me

Very simple. Pull the flame arrestor and you will see a white (though it is probably now black from use) bit of foam material in an opening at the top of the inside of the throttle body. I think I used to take a small blade screw driver and gently pull it out. Then the new one you line up to where it best fits the opening and push it in. You'll know what I mean when you look at how the opening is shaped and how the muffler is shaped. Pic here shows it (part #5).

https://www.mercruiserparts.com/bam/...31816/11414/70

BUP

iTrader: (9)

Not all PCM 555 used the IAC muffler even thou they use an IAC. It all depends on engine serial numbers and if the PCM was sent back in many years ago for the recal and that did include a IAC muffler taped to pcm when is was return back to the dealer in the early 2000s.

And zero DTS engines use a IAC muffler nor even a IAC.

BUP

iTrader: (9)

MerCruiser 496 Mag (H.O. Model) Throttle Body ( Mechanical Throttle-shift ) Parts


just in case any doubters per what I post PLEASE read # 5 script from the link

Bama

Serial # on my engine is OM628104. Not sure if previous owner sent the PCM in for recal or not. I guess if there is one in the TB clean or replace if not don't worry about it. I do have the mechanical throttle shift.

Boat was 10years old and had 145 hours on it when I got it. The flame arrestor was almost completely clogged with belt dust and belt dust was all over the bulkhead. I cleaned everything and replaced and tensioned the belt and the belt dust has been very minimal to current hours of 281. I just didn't know to look for and clean the muffler but the IAC was very clean when I removed it.
From the looks of the flame arrestor when I got the boat the muffler will need cleaning, if there is one in my application.

BUP

iTrader: (9)

I see many people on the VOLVO side install a IAC muffler -- Volvos use the exact 100 % same throttle bodies as MERC and guess what VOLVO never used a IAC muffler ever / never.

People install them but have no idea that one should NOT be installed and the same for some early Merc 496 s. Early Merc did not use a IAC muffler until the PCM / ECM got recaled and then from there on used a muffler except for DTS.

Correct info posted here to make sure the correct installs take place for whomever. Engine serial numbers will determine the correct installs. Anyways have to get back at it.

My point is --- if a muffler is installed maybe someone is clueless or if the muffler is missing maybe someone is clueless. I can careless what the last person or tech did because at times its wrong inwhich is my job to figure all that out before their app leaves my hands. I do not expect boat owners to know this cause they never sat in on an oem class for the correct info but read all the info online thinking its correct.

Woodsy

Hi guys....question....when I bought the muffler it came in a pick of two. When I read about this some posters refer to the filters, plural.

I opened up the throttle body and there are two holes. One of them had a dirty muffler and the other one had nothing.

My question is....are both holes supposed to have a muffler in them or just the one that had the dirty muffler in it? I'm wondering if mine originally had the two mufflers...or if it is only supposed to be the one on the right hand side....

Thank you!!

AllDodge

iTrader: (1)

Just one

Woodsy

Thank You sir!!