# 2008 X3 3.0si surging/bucking problem-no error codes



## gator90065 (Nov 5, 2020)

I have a 2008 X3 3.0si with 130,000 miles. Recently it started to surge and buck intermittently when accelerating from the line, doesn't do it on the freeway. No error codes but I thought it might be bad coils so I replaced them. Initially it seemed to have solved the problem but then it started again with a couple of months. Thought it might be the fuel injectors so I cleaned them, it ran fine for a short while then started again. I finally gave up trying to troubleshoot it so I took it to independent BMW repair shop. I was told it had to be a mechanical issue because no codes popping up. I was then told it was the intake manifold actuator so I had that replaced. It seemed to have solved the problem for a couple of days and then it started back up. Took it back and left it with the repair shop for over 2 weeks. They told me they found the problem and it was the VANOS solenoids and that they were partially clogged so I had them replace the 2 solenoids. Car ran fine for 2 days and then started back up again. The surging and bucking is intermittent. I am at my wits end and will not be taking it back to this repair shop because (1) they can't seem to figure out the problem and (2) I am tired of paying for unnecessary parts and labor. Any suggestions on what could be causing this problem. FYI, the repair shop said they did a flow test and all injectors were performing well.


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## eenerbot (May 16, 2021)

gator90065 said:


> I have a 2008 X3 3.0si with 130,000 miles. Recently it started to surge and buck intermittently when accelerating from the line, doesn't do it on the freeway. No error codes but I thought it might be bad coils so I replaced them. Initially it seemed to have solved the problem but then it started again with a couple of months. Thought it might be the fuel injectors so I cleaned them, it ran fine for a short while then started again. I finally gave up trying to troubleshoot it so I took it to independent BMW repair shop. I was told it had to be a mechanical issue because no codes popping up. I was then told it was the intake manifold actuator so I had that replaced. It seemed to have solved the problem for a couple of days and then it started back up. Took it back and left it with the repair shop for over 2 weeks. They told me they found the problem and it was the VANOS solenoids and that they were partially clogged so I had them replace the 2 solenoids. Car ran fine for 2 days and then started back up again. The surging and bucking is intermittent. I am at my wits end and will not be taking it back to this repair shop because (1) they can't seem to figure out the problem and (2) I am tired of paying for unnecessary parts and labor. Any suggestions on what could be causing this problem. FYI, the repair shop said they did a flow test and all injectors were performing well.


Hey!
Having the same issues as you are having. Replaced the camshaft position sensors, then the Vanos solenoids. Engine light is sometimes off and sometimes on. The BMW dealership is at a loss without further extensive diagnosis. 
The X3 surges, feels like loss of power, etc. Never feels like it is driving properly.


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## HotGrbg (Apr 23, 2021)

Just off the top of my head,
Stator in the torque converter? A slipping torque converter can cause acceleration issues from a stop as after about 35-40 your torque converter lockup is engaged and you won’t feel it on the highway. 
Looked for oil in your eccentric shaft sensor? Eccentric shaft issues can cause all
Sorts of erratic driveability issues.
Ever replace your ignition coils? Sometimes coils won’t set faults if the misfire is sporadic enough. Also they can seem fine but misfire only under heavy load at times ( accelerating from a stop ).


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