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jorgE30 01-09-2013 01:37 PM

MAF sensor cleaning
I'm about to give my E30 a full service, new fuel, air and oil filters, new sparks plugs and change of oil of course. However the car is running a bit rich, only when I accelerate, so I also want to use nulon "foaming air intake cleaner" to clean the throttle and pistons crown and CRC MAF sensor cleaner to clean the MAF sensor.

I don't know if this is necesary to make it run better and more economical or if I could really stuff things up even more. I know the MAF sensor is fragile but I know to handle with care.

P.S the car seems to take a long time to pick up speed when taking off at the lights for example.

I have the BMW E30, 318i with the M40 engine.


mgoods50 01-10-2013 05:08 PM

I don't know what "nulon "foaming air intake cleaner" to clean the throttle and pistons crown" is, but the sound of it makes me shudder.

I've used CRC with success, you can clean the AFM with it. (you don't have a MAF). I use brake cleaner to clean the TB and butterfly.

Back to the foam: Think of it this way-- how on Earth is that stuff supposed to travel into the intake, and onto the pistons equally? How does it burn / change the compression ratio? I'd not even consider whatever that stuff is.

If you want to clean your combustion / fuel areas-- get Jectron, and Ventil Sauber. They are the ONLY products I put into the fuel tank of my BMWs, or my clients BMWs. These are proven, WORKING, safe products.

onager 01-11-2013 02:18 PM

When you say your car is running a bit rich on acceleration, do you mean it blows smoke when you accelerate? If so how much and what color?

mgoods50 has it right I think. The last thing you want to do is to loosen up years of built up carbon deposits or dirt/metal particles that have accumulated over the years or in my case, decades and have them clog a screen or filter or worse scratch the cylinder walls.

jorgE30 01-11-2013 04:22 PM

The nulon foam cleaner works as follows... You put a bit on the throttle plate and wipe it with a clean rag, you put about half the content into the vacuum hose while revving the engine and lastly you take out the spark plugs and squirt some into the slots, crank the engine a couple of times wait for it to dry a put new sparks in. It comes in a spray can of 150ml... Anyway I had a go at it already and so far the car still running hahahaha. The Mat sensor didn't look like any other sensor that I've seen, I pulled out of the air box and sprayed the little wire on top of it, however I was looking for the two wires that run across some sensors, I hope I did the right thing. I didn't go any where near black box on top coz I didn't want break the seal and I don't know what's in it. Changed all filters and oil and it seems to be more responsive. I need a mate to drive behind me to check if still blowing black smoke when I accelerate but when testing it against my white garage wall it didn't leave any spots on the wall, wife is happy. By the way nulon is a highly regarded product in Australia that's why I used it but I agree it does look scary put anything into your engine, never again for me I think. Thanks for you help

mgoods50 01-11-2013 06:55 PM

Ok- that sounds like what people around here do with a product called "seafoam".

Results can't really be measured without looking at tops of valves with a scope-- and users are usually either pro or con, with no one in the middle. The seafoam does have decent cleaning properties, with some lubrication properties also-- just for most jobs there is another that is better for one or the other.

The "smoke" that you see (I'm not a believer) is simply the product burning-- not excessive carbon buildup.

That said, I've used it myself before storing a car for a few months-- I'll dump some into the combustion chambers to keep them free.

That black box is what you need to remove and clean out-- the air filter housing, and the AFM-- don't remove any electrical components. The entire assembly will lift out after removing the intake boot clamp, and loosening the two 10mm nuts along the (here) drivers' side fender area. There's a flap in this thing, the AFM. Clean out that entire box with cleaner and gently work the flap with your finger or a plastic implement. Don't use a screwdriver, you can damage the walls or flap itself.

The TB & butterfly can also be cleaned out with a shop rag / brake cleaner / toothbrush to remove any gunk present. Just don't spay it liberally into the intake of the TB itself.

If you're experiencing hesitation, it could be related to whether the DME is reading the AFM, or ICV. At idle, (TB butterfly closed fully position) the ICV is active. Off idle, or TB butterfly angle off closed position, the AFM is active.

The AFM has a track inside that can sometimes be a little jacked up with gunk.

A good cleaning like I've described of the entire intake tract SHOULD have noticeable results.

jorgE30 01-12-2013 02:54 AM

Thanks for your help mate, have you ever thought of posting DIY videos on youtube via pelican. I you'd get 1000 hits a day and that's just from me hahaha.

You're a champ mate thanks, where i live there is a self serve wreckers (auto salvage?) and next time they get an e30 I'll go and practice on that AFM :)

Nick323 01-15-2013 04:21 AM

Carbo removal the cheapo way
If I want to throw something into my engine to decarbon it, I would use Brake fluid :yikes:
& since I am a decendant from scrooge, I'd use old brake fluid :bigpimp:
But since I do drive spirited enough, I do not need to worry about carbon depositing :rofl:

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