E90 325i - Erratic driving and idling after revs drop

[DuckKnuckle]

Morning guys,

How's it going?

So an issue has now presented itself in my E90 325i.

Whenever I allow the revs to exceed ~5000rpm (usually to overtake or if I feel like putting my foot flat) and then let the revs drop low again after the car changes gears, my general driving and idling becomes extremely erratic.

The only way for me to get rid of the jumpiness of the car is to switch it off and back on again. I've tried changing to sport mode and back, I've tried changing gears myself, but the issue is still there. No warning light comes on when this happens either.

Could this be a timing issue? Is it vanos related?

I'll be taking it in to Brilliant Mechanics next Friday when payday hits cos I honestly don't know what to expect in terms of pay.

Cheers,

 

[Siyaman]

Having the same problem with my E90 325i,last time it did the same thing it was an ignition coil that had gone so it was misfiring.all got sorted after i put a new one.
Now its started again but its not that bad yet so i think its another coil going out.problem is its not throwing any errors yet so i don't know which one it is.


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[DuckKnuckle]

Having the same problem with my E90 325i,last time it did the same thing it was an ignition coil that had gone so it was misfiring.all got sorted after i put a new one.
Now its started again but its not that bad yet so i think its another coil going out.problem is its not throwing any errors yet so i don't know which one it is.


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When I take through to Brilliant next week, I'll let you know what they find :thumbs:

 

[Philip Foglar]

When last was the oil changed, and what is the current oil level? It might be a Vanos solenoid that has some oil sludge or is a bit dirty. These engines and in particular, the Vanos, relies on good oil pressure. Old oil and dirty oil filter don't help either, hence not sticking to the normal lengthy BMW oil service intervals and instead changing oil more frequently.

But, there could be other things causing what you are experiencing. If it is a dirty Vanos solenoid, it is very easy to DIY clean!

 

[DuckKnuckle]

Hey Philip!

I fill up the oil probably every 2000km. Give it about 500ml - 1l.

This usually every 1 - 1.5months.

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[Philip Foglar]

That's right, I seem to remember you mentioned your car uses some oil. This will help, but it may still be a case of the solenoids are not functioning properly or restricting oil flow. The Eccentric shaft sensor is another common failure that can cause a similar problem. Then there is the fuel system, so it could range from a dirty fuel filter which is part of the fuel pump regulator in the fuel tank, or the fuel pump.

Hopefully Brilliant Mechanics can find the cause of the problem. :thumbs:

 

[DuckKnuckle]

Okay so an update on this!

Took the car in this morning and Brilliant Mechanical Workshop ran the diagnostics on my car.

There were a total of 6 error codes, two of which were related to my timing chain and vanos intake.

The vanos intake is R5 500 excl. vat so I had them check if my mech warranty covers it. Turns out I needed to have had the car serviced within the first month of signing for the warranty, otherwise the warranty becomes null and void.

Currently fighting with the dealership now to find out if they had the car serviced before I took ownership.

Fun.

 

[Philip Foglar]

Vanos intake, I gather then they mean the Vanos solenoid on the intake side? If so, then I would seriously try and clean it first! And surely it's not that expensive from the agents?! It is also really easy to DIY replace.

Maybe also list all of those 6 error codes. :thumbs: