[iqraceworks]

I took my "new to me" 2007 335i for it's first drive a couple of days ago after I got the water pump replaced. It was really down on power, and gave me the 1/2 engine warning light, and a 30FF low boost pressure code.

I finally got around to checking the vacuum lines today....and I noticed that both of the boost solenoids bleed vacuum off pretty fast when I hook my mighty pump up to them.

If I pump the vacuum up to around 20".....it will drop down to 0 in a matter of 5-6 seconds. One bleeds off faster than the other one.

Am I correct to assume that this means that both boost solenoids are bad and need replaced?? Will leaking boost solenoids give the 30FF code??

Does the car need to be on (without motor running) to test the boost solenoids? I tested them with everything turned off ..

[Silent9n54]

most likely your boost solenoids might be bad

they are not too expensive and its a good starting point to get rid of your 30 ff code

[iqraceworks]

Originally Posted by Silent11N54

most likely your boost solenoids might be bad

they are not too expensive and its a good starting point to get rid of your 30 ff code

But should they hold vacuum or not?? I don't mind replacing them.....but I don't want to throw $300 down the drain if they are not bad.

[Theana9]

Originally Posted by Silent11N54

most likely your boost solenoids might be bad

they are not too expensive and its a good starting point to get rid of your 30 ff code

+1

[Silent9n54]

Originally Posted by iqraceworks

But should they hold vacuum or not?? I don't mind replacing them.....but I don't want to throw $300 down the drain if they are not bad.

they are probably 50$ each and take 10 mins to change

i changed mine and they got rid of the 30ff code, same with my friends 135i

[iqraceworks]

Originally Posted by Silent11N54

they are probably 50$ each and take 10 mins to change

i changed mine and they got rid of the 30ff code, same with my friends 135i

Well.....I went ahead and ordered a pair of them from FCP Euro. There were both acting strange....I figured that after 12 years, it can't hurt to replace them.

[mweisdorfer]

Originally Posted by iqraceworks

But should they hold vacuum or not?? I don't mind replacing them.....but I don't want to throw $300 down the drain if they are not bad.

You can get a set for $150.00 pierburg is the OEM provider.

30ff codes can be caused by leaks in the intake track and outlets as well.

If it were me, I'd change out all of my vac lines to platinum cured ones. I'd change out the o-rings on the FMIC connectors. Look for loose connections among the inlets & outlets.

Look at your blow off valves. If they see OEM, they too have O-rings.

Check the O-ring where the charge pipe meets the throttle body. Check the other end of the charge pipe.

[iqraceworks]

Well.....I found my problem. Unfortunately, it was after I already ordered new boost solenoids.

As I was pulling the chargepipe to check it out, I noticed that the tube coming out of the FMIC was loose.....the previous owner didn't even get the connection all the way pushed on before he put the clip in....so the pipe was just hanging there....no wonder why I was getting a low boost code!!

Well, I'm sure new boost solenoids can't hurt....along with the new vac lines I'm installing.

Hopefully the thing will run great after I get it all back together.