Hesitation on acceleration
Thread Starter
Junior Member
Joined: Mar 2015
Posts: 57
Likes: 6
From: Calgary, AB
2007 S550
Hesitation on acceleration
Hello!
So I've had this issue for a while now. I've tried quite a few things along the way and been to many different mechanics and they've come up with all manner of diagnoses but the problem is still here.
My friend thinks that it could be a slightly out of place exhaust line from the engine (I was in a crash that damaged the front right side so this is plausible). There is also a popping sound which may or may not be audible in the video.
If you accelerate slowly, it works fine. But if you floor it, there's a 'sucking' sound and it goes silent for about a second and then continues to accelerate. During this process, the lights dim and flicker.
I'm hoping someone has experienced this before and can shed some light on what might be causing it.
I had to upload the video to Youtube, I couldn't find anywhere to attach it here. It's very short (less than thirty seconds) and it shows the problem quite clearly.
Thanks in advance!
So I've had this issue for a while now. I've tried quite a few things along the way and been to many different mechanics and they've come up with all manner of diagnoses but the problem is still here.
My friend thinks that it could be a slightly out of place exhaust line from the engine (I was in a crash that damaged the front right side so this is plausible). There is also a popping sound which may or may not be audible in the video.
If you accelerate slowly, it works fine. But if you floor it, there's a 'sucking' sound and it goes silent for about a second and then continues to accelerate. During this process, the lights dim and flicker.
I'm hoping someone has experienced this before and can shed some light on what might be causing it.
I had to upload the video to Youtube, I couldn't find anywhere to attach it here. It's very short (less than thirty seconds) and it shows the problem quite clearly.
Thanks in advance!
Thread Starter
Junior Member
Joined: Mar 2015
Posts: 57
Likes: 6
From: Calgary, AB
2007 S550
I haven't but I now know it is most likely a vacuum leak. We created a leak on another car and the exact same thing happened so now I'm looking for a a good vacuum hose diagram so I can check them and find the leak. Any help with that would be great.
Thread Starter
Junior Member
Joined: Mar 2015
Posts: 57
Likes: 6
From: Calgary, AB
2007 S550
So I got my hands on a vacuum diagram and checked all the hoses. Found a few small leaks and plugged them. But the problem is still present. Someone suggested it might be a brake booster leak and so I went and got a replacement but that didn't make a difference either. I tried using the method on eBay http://www.ebay.com/gds/How-to-Diagn...8571669/g.html and the first check worked (it softened after I started the engine) but the second one didn't (the pedal rose after being held down for 30 seconds after turning off the engine). Is it possible that both boosters are bad? Or could it be something else?
I have also tried running with/without the MAF meter, it makes no difference regarding the original problem.
That sound from the video I originally posted is still there, and it sounds like air is moving rapidly. If I had to say, I would think its air being sucked IN somewhere.
Any ideas?
I have also tried running with/without the MAF meter, it makes no difference regarding the original problem.
That sound from the video I originally posted is still there, and it sounds like air is moving rapidly. If I had to say, I would think its air being sucked IN somewhere.
Any ideas?
