Hi all,
When driving at constant speed on straight flat section of the motorway, it happens sometimes that the engine “surges” for 1-2 sec: I can hear and read the RPM going down and back then.
This is quite annoying when driving on long distance, however does not happen all the time.
Please be aware that I am not very knowledgeable in mechanic / engine etc… however I’m trying to gather all information to solve this issue, which makes this a long reading (sorry!). But hopefully some other people have experienced the same and could help?
After having had one occurrence of a “check engine “ light on the dash, I have decided to bring the car to BMW. I have explained how the car behaved on constant speed and they could read a fault code related to “camshaft adjustment required”. Engine had a reset of the VANOS, then a test drive and all was found satisfactory. Also, for the sake of having all things done properly at once, I decided to have the inspection II carried out as well. Car has 84’000km (that’s 50’000miles).
I could then immediately feel a difference in the engine response, as if a remap had been performed. This was maybe even more noticeable as the car is an automatic and I could feel the engine was often running under-speed.
BMW dealer also informed me that the ECU will “learn” from the next drives, and that my problem was most likely to be related to short commuting at low speeds, etc…
I am now happy the car is feeling more “alive” and engine is more responsive than before, however my “surging” problem is still there.
My feeling is this is related to an air intake issue, as if a valve or something which is regulating the air flow is shortly limiting the air supply to the engine? This impression is also coming from a general air flow sound that I can hear at all speeds when having the foot on the gas pedal. It seems to come just from the engine bay area in front of me (LH steering wheel).
I had this reported to BMW already before, engine was visually checked and found all ok… Unfortunately I have no experience with another Z4 to compare…
By looking for air intake problem on the forum, everyone points at the DISA valve, but that’s not supposed to apply to N52 engine, right?
Do you think it would be worth to have it checked? But what to look for?
Or am I searching in the wrong direction, could there be anything else than air supply that would explain the surge?
Thanks for your advice :roll:
When driving at constant speed on straight flat section of the motorway, it happens sometimes that the engine “surges” for 1-2 sec: I can hear and read the RPM going down and back then.
This is quite annoying when driving on long distance, however does not happen all the time.
Please be aware that I am not very knowledgeable in mechanic / engine etc… however I’m trying to gather all information to solve this issue, which makes this a long reading (sorry!). But hopefully some other people have experienced the same and could help?
After having had one occurrence of a “check engine “ light on the dash, I have decided to bring the car to BMW. I have explained how the car behaved on constant speed and they could read a fault code related to “camshaft adjustment required”. Engine had a reset of the VANOS, then a test drive and all was found satisfactory. Also, for the sake of having all things done properly at once, I decided to have the inspection II carried out as well. Car has 84’000km (that’s 50’000miles).
I could then immediately feel a difference in the engine response, as if a remap had been performed. This was maybe even more noticeable as the car is an automatic and I could feel the engine was often running under-speed.
BMW dealer also informed me that the ECU will “learn” from the next drives, and that my problem was most likely to be related to short commuting at low speeds, etc…
I am now happy the car is feeling more “alive” and engine is more responsive than before, however my “surging” problem is still there.
My feeling is this is related to an air intake issue, as if a valve or something which is regulating the air flow is shortly limiting the air supply to the engine? This impression is also coming from a general air flow sound that I can hear at all speeds when having the foot on the gas pedal. It seems to come just from the engine bay area in front of me (LH steering wheel).
I had this reported to BMW already before, engine was visually checked and found all ok… Unfortunately I have no experience with another Z4 to compare…
By looking for air intake problem on the forum, everyone points at the DISA valve, but that’s not supposed to apply to N52 engine, right?
Do you think it would be worth to have it checked? But what to look for?
Or am I searching in the wrong direction, could there be anything else than air supply that would explain the surge?
Thanks for your advice :roll:
