Just want to thank the brotherhood once again. Over the last few drives my car had been running progressively worse and worse. The idle was all over the place, it seemed to hesitate when pulling away from a stop and CEL 1-4 was popping up with ever increasing frequency. I was about to make an appointment to have the car looked at but decided to search through some threads here first. After reading about cleaning the MAF I went ahead and gave it a try. WOW!!! What a difference. Idle is pegged at 1000 rpm, not a bit of hesitation and not a flicker of CEL. Needless to say I will not be making that appointment with the mechanic.
Glad you were able to fix the idle and cel issue. Using a k&n the oil plus dirt causes that on my '90. After air filter oiling I usually had to clean the maf's a few times in the coming months though cleaned electrical maf connections, thermo sensor and coil pack connectors at the same time. Went away completely. Slightly overfilling the motor oil on a top off seemed to affect the cel flickering in the same way so the oil level on the dipstick just under max ~3/4 running warm worked best.
What procedure did you use- did you remove the Maf and physically clean it or just spray it in? My 355 runs great- I was thinking of using that maf cleaner on my daily driver...
Removed MAF on the right and left banks. Cleaned the screens and sprayed electronic cleaner through them. I also cleaned the connections and checked the resistance across points 1 and 6. Both were reading 389 ohms but since the car was running quite well after the cleaning I figured there was no reason to make any adjustments to those numbers.
Great! I guess it can't hurt to try that on my daily- I have a feeling it's like a mini tuneup if the maf is getting dirty but bad enough to need to replace.
Hi Amattox, Well done, sounds like you got it sorted. Do you have the link you found that you used for reference? Thanks.
Sorry for the mis-post- I meant what Amattox1 did would be good if a maf is getting dirty (therefore affecting performance) but not bad enough that it needs replacement. I always wondered if the MAF in some of these cars has shortened life due to the excessive heat generated....i.e. my BMW MAF lasted probably close to 100K miles whereas my 360 needed new ones (both within 6 months) probably after around 20K miles. I haven't been able to actually drive my newly acquired 355 so not sure if the underhood gets as hot as the 360 (360 had sort of side vents in the engine lid to allow the glass window whereas 355 has a bunch of the cheese grater slots which may vent better than the 360?). The heat was a theory of mine on the 360 anyway. The other thing (not looking to start an argument on this) but I feel the K&N style filters are no good in that it just seems to me filters that are oiled cause more troble than they are worth- caused issues on the 911s when I had one and followed the porsche forums, and I've heard about it fouling up MAFs in other cars (including Ferraris as discussed elsewhere on f-chat), particularly if people inadvertently over-oil the air filter when servicing it. I have never used anything other than OEM air filters because of this (which are paper).
I had an e39 m5 and the MAF sensors gave a good bit of trouble. Cleaning had minimal effect. I replaced mine at 40K on the m5 and it made a huge difference. I remember someone had discovered that some VW had the same MAF sensors that cost next to nothing compared to the OE BMW. It was also well known about K&N filters screwing up the sensors on the BMW. The car would just run crappy and stumble at high rpm's and not give any codes. Glad you got it running good again. I put in new plugs and wires this weekend and it made a huge difference. I think mine were original. I haven't driven it yet, but the skipping and rough idle seems to be gone. It is a good feeling!
The throttle response difference between k&n and paper filters was significant on the 348. It is worth the trouble for me to have a much better response and a few extra ponies traded off with minimal upkeep. My Porsche Turbo has similar issue so I just clean the filter every few months and it runs well.
Hi Dave, I also have a K&N in my 348. Just to clarify, was yours better with or without the K&N? Thanks.
I just put "MAF cleaning" into the search. Read through about half a dozen posts. They were all pretty consistent on the cleaning procedure.
With k&n is way better. The paper filter did nothing good other than remove fine particles but stop Cels. I tried to get the company that makes green filters to fit one for the 348 box but they said no. The green filters flow as much as k&n but did not require oil. This would be the best solution. Dave
