TGstring

The motor is completely stock and unmodified. approximately 65,000 miles/ 105,000 km.
5spd manual sedan.

No codes or issues otherwise.

I have found that under very light acceleration and very light load that I notice, for lack of a better word, the slightest surging between the 1500-2000 rpm band.

The give you a better sense of what I mean, it feels like you're on a boat (ok, maybe a big yacht) and you get the slightest feeling of being on water.

Definitely not lugging as I can feel it under light to no load and the hard chugging of lugging is distinct.

I wonder if anyone else has felt something like this and whether or not it's simply inherent in the way they (these motors) are.

Cheers

robert3108

iTrader: (1)

Check your spark plugs and when was the last time you changed your air filter?

Tundraboarder666

motor mount maybe?

TGstring

Air filter is clean (new) and I havne' thad a chance to look at the plugs... didn't think they'd be toast after only 65k...

Never really thought a motormount would be it- that would mean that the motor itself would be very shaky between that window of revs and a weak mount would transmit that to me... doubt that.

I guess noone else has really noticed anything under light throttle/load between that window?

robert3108

iTrader: (1)

Well iv got a 06 2.2 and some cold starts..if I haven't let it warm up some and back out and go...about around 2k or so its like sluggish..like it will go then stop the go again..then stop then after that its fine...well not so much if your spark plugs are fried...but you are getting closer to 100k for when you need to change them..I pulled mine out at 100k and look like someone ran .them through the dirt...wouldn't hurt the look..but try one day and let your car get warmed up..then see if it happens..have you had like any power failure? Battery dieing? Get your altenator checked..its hard to tell or its just the car itself but if you were feeling like you are riding on a boat then I would check your shocks and springs

robert3108

iTrader: (1)

Hope this helps

Tundraboarder666

I wouldn't be surprised that it's the motor mount... you still have the stock one? and if your car is a 5 speed... I know what you're talking about the surging between the RPMs. Get the upgraded poly mount from TTR and it will go away.

TGstring

I've done some more reading... apparently the mounts are know to be too soft?

I have read that sometimes people have felt a "knock" for lack of a better term when sitting at a stoplight in neutral and then put it in 1st gear.

come to think of it, I do believe I've felt that before.

I'll see if I can take a closer look at the motor mounts. Maybe I can try filling them with urethane to stiffen them up if they're not toast...I remember doing that years ago and it worked well.

Notwithstanding, that would mean that the motor is shaking quite a bit within those revs which would mean to me that there's another problem or issue at hand.

I found it interesting that GM does not provide a baseline recommendation on what the minimum rpm should be in gear.

For example, in my Corvette manual, it says to always keep the revs above 900rpm. (God Bless Torque :P )

An old mazda winterbeater I used to have said to always keep the revs above 1200 when in gear.

I couldn't find that anywhere for the ecotec. Makes me wonder if I'm really lugging at 1500... but I just can't see that being the case on a motor that makes 155lb/ft at a respectable 4krpm

Lemme see what I can find...

Tundraboarder666

They make the motor mounts that way so your car doesn't vibrate like a giant *****... If they were solid it would rattle the entire frame...

robert3108

iTrader: (1)

You can get some poly bushing for like $50 at TTR turbotechracing.com like tundra said was talking about.nstall yourself and kind of narrow it down some? I guess its hard in both aspects one trying to describe it and uso trying to diagnosis it with out being.there.

Raven1210

I'm having the same problem with mine, I was wondering if you ever figure out what is was and how you fixed it

Tundraboarder666

3 posts... so you just read the first post okay, cool.

Raven1210

Umm what tundra? I don't see how they managed to fix there problem. And the issue in my cobalt is exactly they discribe in the first post. Mine is a 06 2.2L

Raven1210

And I'm not a newb to forums if that's what your thinking. I signed up to this forum to see if someone could help me with my problem on my car. I did a search and came across this one that matches the same problem I'm having. I see there's others but there a little different but I tried to clean the intake, maf and replaced my plugs with no luck. So I hoped that he would see this post and update how he fixed. So thanks for trying to be a dick. Also I highly doubt motor mounts would cause this problem, because it doesn't shake on idle. But I've been wrong before and I'm willing to try what people have to say. And I'm not going poly mounts so it can shake the **** out of me. I've driven other cobalts and they don't have this problem so that's another reason why I don't think it's the mounts

scagnetti76

Rpm surge sounds etc or maf related to me. Could be trans too if auto. Does it do it at stops? No codes is kinda weird though.

scagnetti76

Nvm... too much beer here. Lol