Vanos solenoid vs seals failure symptoms?

[ZFawbs93]

I feel like something is definitely wrong with the vanos unit in my car. The only thing in unsure of is wether or not it's the solenoid itself or the seals. What are the different symptoms for each?

[e36fiend]

The solenoid will give you at least two different check engine codes. 1) if it's unplugged and 2) if the cam position sensor detects that it isn't advancing the cam far enough. I would think that if the seals were far enough gone then you'd see code 2 but my experience has told me otherwise.

Basically it's difficult to test those conditions without an air compressor and DIS.

[ZFawbs93]

The solenoid will give you at least two different check engine codes. 1) if it's unplugged and 2) if the cam position sensor detects that it isn't advancing the cam far enough. I would think that if the seals were far enough gone then you'd see code 2 but my experience has told me otherwise. Basically it's difficult to test those conditions without an air compressor and DIS.

There's no check engine light at all. Just seems to be down on power and hesitant below 3000 rpm's. Usually a rough idle when at a stop or initial startup as well.

[Eric93se]

Rough idle has nothing to do with the vanos. You might need to do some tune-up work. Check for vacuum leaks. If you oxygen sensor is original or very old go ahead and replace it, you lucky you only have one and its cheap. Run some fuel system cleaner like royal purples fuel system cleaner.

Test your CPS to see if its in spec.

[flyfishvt]

Go to Biesan Systems and read up on Single Vanos. Except for your rough idle you have classic vanos oring failure symptoms. My 95 325 did the exact same thing. I replaced the orings and it was like driving a new car. I think the key thing here is that you are not getting a check engine light. As mentioned above a solenid failure will generate a code. The orings generally will not.

As mentioned above there are procedures to test the solenoid with an adapeter and compressed air but to do it the right way you really need software to read the engine while you are doing it. One thing to keep in mind is that Vanos Oring failure is 1000 times more common than Vanos Solenoid failure. Dont dismiss the obvious when it stares you in the face

[cmor7965]

What's sort of hesitation do you get below 3k rpm? I get the bunnyhops, sometimes its bad othertimes its barely noticeable. Then when it hits 3.5k rpm it pulls hard. Im not sure if its oxygen sensor, vanos seals or cam sensor (sorry to hijack thread).

If you manage to fix the issue it'd be awesome if you replied.

[ZFawbs93]

What's sort of hesitation do you get below 3k rpm? I get the bunnyhops, sometimes its bad othertimes its barely noticeable. Then when it hits 3.5k rpm it pulls hard. Im not sure if its oxygen sensor, vanos seals or cam sensor (sorry to hijack thread). If you manage to fix the issue it'd be awesome if you replied.

Mine at low rpm just feels like the car is holding itself back as far as power goes then around 3-3.5k it cracks and starts pulling hard. It's definitely something I notice, but I'm also a little OCD with how my car runs

[morzada]

I'm also a little OCD with how my car runs

That's why we're all here.

[ZFawbs93]

Don't worry guys some drunk asshole hit my car last night and probably totaled it so looks like I don't need to worry about this vanos issue. Not the way I recommend solving the problem...

[e36fiend]

Ouch, that sucks dude. Same thing happened to be a few years ago. Parked my car for 24 hours while I rented a moving truck, dropped off the truck in the middle of the night and my car had been totaled sitting on the side of the road. I lucked out and there was a business card from the Seattle police on my windshield saying a drunk driver had been arrested after hitting my car and I got his insurance info.

[Graf Spee]

Hey guys, I’m reviving this dead thread here. I am experiencing exact same issues. Rough idle at start and sluggish until 3k rpms then it really opens up big time. My car is throwing a code for variable valve timing sensor and o2 sensor. So I have ordered a used vanos solenoid off line and plan to swap them tomorrow hopefully it clears it up. Guess I ought to get the o2 sensor while I’m at it even though it was replaced less than 10k miles ago. If this doesn’t work I’m going to go with dr vanos and replace the spark plugs while I’m at it

[B234R]

A question about this, if I disconnect the solenoid and start the engine, apart from a CEL will the engine suffer any damage? Just for seeing the difference between running the car with the solenoid plugged/unplugged. My car is an early ´96 328i.

[Eric93se]

Unplugging the solenoid will not do any damage.

Graff, you should use another scanner because our cars do not have a "variable valve timing sensor". You can also test the solenoids resistance, your problem is like most, the seals in the Vanos need to be changed. When doing the oxygen sensors do the pre-cat sensors even if the code is for the post cat sensor. If you have two pre-cat sensors then do both at the same time.