M60 MAF cleaning

[Alpinewhite]

Hi All,

I have this rough idle and CEL problem on cold mornings. Before I spend $ for PCV and other seals, I want to do all the cleaning/checking stuff. 2 days ago I cleaned ICV and this improved things a little. I want to also clean MAF. Can I use CRC MAF cleaner and just spray that stuf inside the MAF tube? I dont want to get the sensor out and dip in 90% alcohol as some people suggest. It is quite expensive ~$400; I dont want to spoil a good one.

Problem in a little detail if interested:
On very cold days (< 40F) after the engine starts rpm is falling to 300 range and car shudders real bad. Immediately it adjusts to 800 range. After moving a while at the next stop and go(traffic light) rpm again falls to 300 range and CEL comes up. CEL stays for 10 mins and then I wont see the shudder or the CEL until next cold morning. I had this same problem at the end of last winter and I had a smooth bimmer for the whole summer. May be my car needs flu shot .

Thanks
Arun

[The Bigfella]

I wouldn't be spraying it inside the tube - I'd be removing the MAF and spraying it - otherwise, where is all the crap going to go?

I've heard that cleaning the ICV isn't the best thing to do, as they are lubricated.

Have you done a stomp test to find out the fault codes (try searching for it)

[632 Regal]

I took the ICV out and it was quite gummed up when I twisted it in the air the valve would stick. sprayed it with carb cleaner til it was silky. Might look into that again as I put 30k on it since.

[BillionPa]

"On very cold days (< 40F) after the engine starts rpm is falling to 300 range and car shudders real bad. Immediately it adjusts to 800 range"

that is EXACTLY what happens to mine, however it happens any time the engine is cold cold, even if its 60F out. However, once mine hits 600rpms (thats my cold idle speed) it has no more problems.

this only started happening about 2 weeks after i cleaned out my ICV. when i do the intake gaskets im gonna clean it again and use WD40 or something in there, as i believe its just sticking for a second.

MAF cleaning is a good idea, every once in a while. the MAF should auto clean itself with heat, but that doesnt get everything off of it.

the OTHER thing that may cause this behavior is the voltage regulator bushings in the alternator, but getting to that on the M60 is a real pain in the ass, so im not gonna do that unless things go south.

[brosher]

I had the same symptoms as you. My car was fine in the summer when I bought it but as it got colder things progressively got worse. I did all the intake gaskets and new PCV plate and everything is mint now.

To clean the MAF I just used electrical contact cleaner. Spray a steady stream right on the little piece of metal for a while. I don't think this cleaning is going to solve your problem though. Goto autohausaz.com and fill up your basket with intake gaskets and such. You should be under $150 for everything. Took me about 10 hours and I'm an amateur. The most time is spent using vice grips to get the stupid torx bolts out that will strip. Plan on replacing these with some hex ones.

Do a search, there is an excellent step by step how to for the intake gaskets.

[brosher]

"On very cold days (< 40F) after the engine starts rpm is falling to 300 range and car shudders real bad. Immediately it adjusts to 800 range"

that is EXACTLY what happens to mine, however it happens any time the engine is cold cold, even if its 60F out. However, once mine hits 600rpms (thats my cold idle speed) it has no more problems.

BillionPa,

Make sure you reconnected the idle control valve to the proper connector. I forgot to reconnect mine once and this is what happened. If it is connected try spraying some electrical contact cleaner in both sides of the connection.

[BillionPa]

i did clean the connector and used electrical lube on it too (same with my oil level sensor)
however the problem only occured 2 weeks later when it got really cold.

and the idle stabilizes after about 1.5s, so the ICV is definately functioning.

i am running 10W40 dino oil right now as part of an autorx rinse cycle, so im sure thats part of the problem.

[The Bigfella]

The most time is spent using vice grips to get the stupid torx bolts out that will strip. Plan on replacing these with some hex ones.

Ah, maybe spend 30 minutes buying some Torx tools?

[bsell]

When is the last time you clean your injectors? Cold weather puts the hurting on atomizing gasoline. Especially if the stores and distributors are still pushing the summer formula package (hot weather). As the weather cools, the gasoline manufacturers reformulate the additive package to make the gasoline atomize better in cold weather. Add in some injectors that are squirting streams of gas versus spraying a mist and you could very well get the same symptoms.

While you are cleaning things, get at the throttle body with the carb cleaner. What happens over time is the small gap around the throttle butterfly valve gets stopped up with goop, causing less air to get around the mostly shut butterfly valve. Cleaning the goop out gets the idle control valve back to working in its normal operating range.

I don't know how many cars of all makes I have 'fixed' by doing the above procedures. Sometimes all you need to do is wring the engine's neck with some WOT runs to redline to blow the crud out off the valves/combustion chambers and injectors (finally allowed to fully open ).

Of course, if you have vacuum leaks, life will never be good until they are cured. A couple minutes with the carb cleaner, spraying the gasket areas related to the intake manifold should tell you if you need to go through the pain of swapping intake manifold and throttle body gaskets. Any changes in idle speed are sure signs of vacuum leaks.

Brian

[brosher]

Ah, maybe spend 30 minutes buying some Torx tools?

Have you ever done an intake on an M60? I have the proper torx ratchets. Even the most careful person can't get them out with the proper torx. The heads are so soft the bit just chews them up and they are seized on there pretty good. Maybe you will be lucky but I know I am not alone.