[02fbody35th]

So I've noticed something a little odd today. Sometimes when driving on the highway if I take my foot off the gas and just coast for a few seconds, the car does this weird shudder. It almost feels like the clutch disengages for a split second and then reconnects. It kind of feels like when afm cars go from v4 to v8 mode but my car is a manual and does not have afm. Has anyone else experienced this? I'm wondering if maybe this is just a common trait of the dual mass twin clutch these cars come with. But I don't know.

[clanky]

Well I am glad I am not the only one that notices that. It does it everytime after so many seconds. I test drove another one and it did the same thing... so I would assume it's normal but who knows. I would be very curious to find out what it is exactly doing.

[02fbody35th]

Originally Posted by clanky

Well I am glad I am not the only one that notices that. It does it everytime after so many seconds. I test drove another one and it did the same thing... so I would assume it's normal but who knows. I would be very curious to find out what it is exactly doing.

Yes exactly! After a few seconds of coasting it does it. Well it's good to hear that it's probably normal

[Whitemaro6]

YES! Mine does this most notably in 5th gear. I think it might be the vvt kicking off causing the rpms to drop monetarily. My guess

[macgoober]

Do you pay attention to the instant fuel economy when it does this? Does it go straight to 99mpg?

Could just be engine braking.

[02fbody35th]

Originally Posted by macgoober

Do you pay attention to the instant fuel economy when it does this? Does it go straight to 99mpg?

Could just be engine braking.

I haven't watched the mpg counter but I don't think it's the engine braking. It's almost like the car jumps forward then settles in. Or the best way I can describe it is it feels like the clutch disengages for a split second. It's not very drastic. Most people probably wouldn't even notice it.

[KyBoy]

I looked for that yesterday, tried to see if my car would do it. I could not.

Heath

[KenH.]

I've noticed this as well. It feels like the car reduces the engine braking for half a second and gives the throttle a very slight bump and you surge forward then the engine braking resumes.

Sometimes it makes my wife thinks I'm driving like a goon slowing down for a light then a little bump of speed as we get close to a car. It does actually speed you up for a split second. Pushing in the clutch while coasting doesn't have the same effect as the issue.

[02fbody35th]

Originally Posted by KenH.

I've noticed this as well. It feels like the car reduces the engine braking for half a second and gives the throttle a very slight bump and you surge forward then the engine braking resumes.

Sometimes it makes my wife thinks I'm driving like a goon slowing down for a light then a little bump of speed as we get close to a car. It does actually speed you up for a split second. Pushing in the clutch while coasting doesn't have the same effect as the issue.

Well said, that's exactly what it feels like. Must be normal

[Boilermaker128]

Could it be a form of DFCO? I think it means deceleration fuel cut off. Suppose to save fuel. It's not that noticable on my 2010 DI LNF cobalt sstc when cruising. But if say I downshift semi hard to help slow the car down you can really feel the DFCO, along with a slight change in sound.

[RicSimonis]

Curious at what RPM do you notice this?

I've noticed something similar at around 1200 while downshift braking, in any gear, there's a bit of a "bump".
Not sure what the "official" term is but it appears to be just where the engine's ability to "brake" drops off and it wants to GO instead of stop.

(Sorry for being so technical.)

[02fbody35th]

Originally Posted by RicSimonis

Curious at what RPM do you notice this?

I've noticed something similar at around 1200 while downshift braking, in any gear, there's a bit of a "bump".
Not sure what the "official" term is but it appears to be just where the engine's ability to "brake" drops off and it wants to GO instead of stop.

(Sorry for being so technical.)

I'm not sure exactly what rpm. But it's lower in the rpm range. Maybe like 1500. I've noticed in 5th and 6th gear

[SS 1LE]

You guys sure it's got nothing to do with the rev match?

[RicSimonis]

Originally Posted by SS 1LE

You guys sure it's got nothing to do with the rev match?

I'm seeing it when the clutch is engaged and slowing, regardless of Rev Match, right around 1100-1200 RPM. I believe this to be a normal condition, I would have expected it at a lower RPM but no concern here. Just trying to help possibly explain it. The engine is approaching its idle RPM and looses the ability to slow the car. Essentially a good point to down shift unless going into 1st.

Just my $2.47 ($.02 adjusted for inflation).