Intro/theory-

If you’ve seen my other thread lately, you’ll know I have taken the top off my intake manifold to vacuum some debris out of my cylinder heads

this is a huge no-no according to mercedes. Apparently the entire intake manifold is supposed to be removed instead and the manifold should never be opened. Whoops too late! I’ve read this is because the manifold is tricky to seal, so I wanted to start this thread to document my process with pictures and explanations of results

I’m kinda glad I split the manifold because this thing was absolutely filthy inside. And if you’re into the performance world you’ll know this robs your engine of power

there isn’t a lot of info online about working on these manifolds, and most of whats online has old photobucket photos which are no longer available, making the threads and info halfway useless

on the subject of this part being “non serviceable” I personally think that is a joke. It’s good in theory, it prevents a lot of people from doing a half assed job on sealing their manifold and ruining their cars performance with vacuum leaks. If you remember right our transmissions were “non serviceable” and “sealed for life”, what a joke. It’s this same “non serviceable” attitude that I believe ruined the reputation of the Abc system, because if mercedes developed and shared a PROPER maintenance schedule for Abc, we would have seen exponentially fewer abc failures in my opinion, but I digress

like I mentioned, this part has been serviced before with success. In fact in the 2000’s there were multiple people opening these manifolds to port and polish them, one user claimed an Hp gain of 20. I wish I had more time to devote to porting and polishing my intake, but unfortunately I have just bought a house and this intake repair job couldn’t have come at a worse time. Apparently it takes upwards of 80 manhours to properly port and polish these manifolds, yikes . But a 20 horsepower gain for $0 is right up my alley haha

heres some pics of my manifold top piece after being painted with DupliColor engine enamel, color Aluminum. No other color looks right in my opinion. And remember you want very very thin layers of paint because unfortunately painting these pieces will make it retain heat and possibly lose some power. I however am looking to ultimately restore my mercedes to a really stellar condition all around

Prep/application of sealant


To clean and prep these pieces I started spraying with brake cleaner, it was clear a brake cleaner bath would not get these pieces clean

cleanliness is absolutely crucial to applying sealant to metals

so what I did is I soaked the pieces overnight in some gasoline. Make sure to keep the plastic brake vacuum barb OUT of your gas/brake cleaner bath. I believe fuel and brake cleaner will eat away the plastic

after soaking overnight, I scrubbed all the pieces until they were visually clean. This fuel bath helps a lot to loosen all the old sealant and old glue. After a fuel bath the pieces will be coated in a thin oily film. Now here’s where you spray them down with brake cleaner again

removing all of the old sealant is also absolutely crucial to adding new sealant


so here’s a photo, maybe the only one on the internet, that shows the sealant pattern for the inside of the upper manifold. Keep in mind this is a very hasty application of high temp RTV and I ended up removing and re-doing the sealant. Main issue with this sealant application job was using too much sealant. Not only is this going to have too much push-out , but this will also inhibit air flow through the manifold with how much extra sealant would be squeezed out. It could even possibly break off in pieces and get sucked into the cylinder head. Not good




be prepared to do the same if you want proper results

Please note- the very top and bottom line of sealant, I did not find these lines of sealant when dismantling it. I’m not sure if those parts had sealant originally but I don’t see what it would hurt


To start I took apart the pieces and studied the patterns of sealant and glue meticulously. This is very important for getting the right patterns. You’ll see where the old sealant goes after stripping and cleaning the pieces. It’s pretty clear where the Sealant goes because it will be the only strips on the manifold that isn’t discolored with oil film