E46 M3 - jerky/hesitation when accelerating

Peertjies

Active member
Hi.... What whould the cost of a TPS sensor be and how difficult is it to install? I'm thinking I need to replace mine as well.
 

Khalid Essa

New member
M3west said:
Hi Guys,

I have symptoms exactly like the guy in this post I have found on Piston Heads. I was wondering if anyone has suggestions?

I "borrowed" his post as it it explains my issues 100% :thumbs:

Evening all

My 05 E46 M3 convertible sometimes sufers from a hesitation when accelerating, when it does it its like you are coming off and on the throttle really quickly. I can't get it to do it at will, it just "happens" seemingly randomly. I believe its doing it in the lower half of the rev range, and I've experienced it on both full and partial throttle. Thinking back, its been doing this for many months, but due to the infrequency I've not given it much thought. Its only recently that I have come to the conclusion that there is something "wrong". It is NOT the traction control activating, this is a lot more violent, its literally like coming on/off the throttle very rapidly. I have always used quality super unleaded petrol from when I first bought the car, so I don't think for one minute its dodgy fuel causing this. If I had to have a guess, I would say its an electrical issue, but I'm not a mechanic.




The car has done less than 30K with full BMW history, its due an Inspection 1 in around 5500 miles. Its still under AUC warranty so I can take it back to the stealer to look at. However, because it does it intermittently, I can't show the problem to them, knowing my luck they won't be able to replicate the fault. Would an intermittent fault like this store a fault code on the ECU which they could then read? If there isn't a fault code stored, I doubt they will be able to fix it as they seem to rely on the magical BMW diagnostic computer telling them what to do. Also, If its not something covered under warranty I don't want to take it to a main stealer as they will no doubt pull my pants down, if its something I've got to pay for to fix I will take it to a reputable indy.

I would appreciate any help offered as this is starting to spoil my enjoyment of the car. The straight six engine should be silky smooth, when it does this jerking its like I've got Parkinsons in my right leg

Many thanks in advance


Thanks guys....
 

Andy1GP

///Member
Gizmo said:
It sounds more like the throttle actuator is giving in. Have replaced them before on the e46 M3 and the e39 540i. It will throw a code if its misbehaving. Get those fault codes read.:fencelook:

Who did the throttle coding for you Warren? This is the only thing holding me back. If Gertinator can do it then I will be pleased :)

I'm going to start off replacing the TPS sensors first. Followed by the actuator. It's a kak expensive part though.
 

Andy1GP

///Member
I ended up replacing the other one as well. Located on the actuator itself. The problem started creeping back and for now it seems to be behaving again. Car is still adapting and feels even smoother low down. Vanos is behaving better in harmony with the throttle adaptation.

Sent from my SM-G900F using Tapatalk
 

Xack

Active member
Andy1GP@TheFanatics said:
I ended up replacing the other one as well. Located on the actuator itself. The problem started creeping back and for now it seems to be behaving again. Car is still adapting and feels even smoother low down. Vanos is behaving better in harmony with the throttle adaptation.

Sent from my SM-G900F using Tapatalk

Waiting for the day you do a diy on vanos:cartel:....cos on that day, iam bringing a case of beer and a ton of meat to braai,lol

Iam gonna do these to sensors aswell as soon as my O2 errors clears.
 

Andy1GP

///Member
The vanos adaptation values will give you an indication of the o2 errors. I mean to say incorrect vanos timing could cause p2 errors or excessive o2 values

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Xack

Active member
Andy1GP@TheFanatics said:
The vanos adaptation values will give you an indication of the o2 errors. I mean to say incorrect vanos timing could cause p2 errors or excessive o2 values

Sent from my SM-G900F using Tapatalk

Yip, ive heard so, thing is I haven't touched the vanos yet...saw you did the vanos solenoid pack on the silver e46 m3, maybe I'll try doing that first, if it's gonna even do anything,lol
 

Andy1GP

///Member
No further update on this?

I am suspecting throttle actuator. It is a mighty pricey part and a fair DIY that doesn't seem to occur all that commonly. But might just be the case.
 

Rotinaj

Active member
Mine did that, swapped the TPS's and it was smooth as silk. Any out of range values on the OBC or codes.

If not i do have a spare actuator sitting in my garage.
 

Andy1GP

///Member
Rotinaj said:
Mine did that, swapped the TPS's and it was smooth as silk. Any out of range values on the OBC or codes.

If not i do have a spare actuator sitting in my garage.
So you haven't replaced your actuator yet? I also chaged both the TPSs but its starting to come back.

From what ive read and understood it could be the actuator itself however ive never had any codes or lights whatsoever. Unless my code readers are defective. I would like a second test elsewhere if possible.

On the to do list next is injectors (as i have them already) and fuel pump (in tank) and checking the fuel pressure regulator. Will also swap out actuators to see if that makes a difference. And report back.

Sent from my SM-G935F using Tapatalk
 

Andy1GP

///Member
After I had BMW Leo Haese Pretoria run a vanos test on the car the hesitation was as good as sorted!

Many thanks to John lodder from Leo Haese as he organised the Brake fluid flush special as well as Aircon gas top up. HAven't enjoyed the car as much before all this was done.
 

ChrisBrand

Staff - Legal
Staff member
VANOS test can be done on INPA but always good to have experts to tell you exactly whats wrong if there is something wrong with the Vanos
 

Andy1GP

///Member
Rotinaj said:
Is that not something INPA/DIS can do? The Vanos test that is.
Im yet to find someone thats inpa can do that on a MSS54 dme. Mine can do the test on the Z4M MSS70 but ive not seen one do an M3 before. Rheingold ista D yes.

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