n00dleboy

Every now and then when i'm cruising, normally in 4th or 5th, and i'm accelerating very lightly, all of a sudden it'll be as if the car stops accelerating even tho my foot is still on the gas so it feels like a slight jolt and then i feel the car start accelerating again. The feeling is the same as adding a bit of constant gas to it, then releasing the pedal of a sudden and then adding the gas again. I'm not sure if it's my clutch that all of a sudden just doesn't grab or is it something else. There is no slippage at all when i'm driving, this happens maybe a few times a week. Very strange - does anyone know what this could be?

Allout

Is there a particular RPM that this is happening?

allmotor_2000

This happens while cruising sometimes... the car will bog for a second or so. It should never happen while under WOT. If you have a wideband O2, you will see the car go lean 19.x AFR during that time when it is hesitating - something screwy with the factory O2 sensor or maybe even the ECU. I changed my O2 but it still does it sometimes.

The sensation is felt because the car runs lean and then when the ECU correct for it, the power comes back.

It's not the clutch!

BlueCLS6

Is it right after the car is warmed up? That's when mine does it... I believe the car maybe switching from open-loop to closed-loop mode, if you are familiar with control systems. It only does it once (not every time) and usually when I first start driving it, that's the only thing I could think of.

ChadT

I've felt that on rare occasions. Don't think it's anything serious. I've only felt it when I've been babying the car which isn't too often.

n00dleboy

yea ok.. im feeling better now - so nothing really big to worry about?

Normally happens when i first start the car and take off, after it's warm i don't normally get it, and yes it never happens if i give it hard gas or WOT.

Is this something i should have the manufacturer take a peak? The ecu or O2 sensor?

Thanks,

ChadT

Sounds normal. The ECU seems to do weird thinks at part throttle on my car anyway. Especially when going from a light throttle cruise to giving it just bit more gas.

PimpinCLS03

Hey GUYS,
Too all who have replied to this thread, I am a 6 speed owner and I also have the same problem. What I would like to know is, do you all have Comptech Headers? The only conclusion I can come up with is that maybe the O2 Sensor gets screwed up with the headers! Please let me know guys, because i took it to the dealer and the told me it was my clutch, but my car only has 24K on it. So i don't believe that shit.

Mario

BlueCLS6

It's totally NOT the clutch and yes I have CT Headers... well at least the collectors (still does the hessitation thing with the turbo). I think it did it before the headers (i.e. stock) but I can't remember. It's not a big deal at all anyway...

Roady

Not to worry - my car did this before the CT headers and still does it - I believe it's a normal warm-up type of thing.

Shawn S

Mine’s been doing this on occasion for the last 3-years.
Scared me the first few times, but it doesn’t anymore.

On my way home from work, there’s one stretch of road that it happens in the same place all the time if traffic is right.
I concluded that it was something that happens when the engine’s warmed up.

Roleez

That's a characteristic of all MTs simply because of the direct connection from transmission to engine. Such an occurrence varies with the angle of the road you're driving on (more so on slight downhill angles and occasionally on flat surfaces as well). You'll never see this in an AT, however. Why? MTs don't have a torque converter. But if this happens non-stop, most likely you've got a bad engine mount.

n00dleboy

no i don't have headers, everything is stock and i have 6mt.

I'll take it as normal, but i'll just briefly mention it to the service guys to take a peak to confirm that my car is fine. I've had several manual cars and none of them did this, perhaps the cl-s 6 is special

allmotor_2000

It did it before the turbo and after the turbo... with Comptech Headers. I don't remember experiencing this when the car was stock. However, with the wideband I notice it more often - the ECU is 'hunting' for 14.7 AFR.

Anyways, it happens always when the car is cold and less-often when cruising - its only on very light throttle... very light - it goes to lala land. I think it also has to do with the TPS sensor - I have mine adjusted to get good throttle-response and eliminate that 'lag' when you initially punch the gas; this is a side-effect.

I think there is a sweet-spot for the TPS, you'll just have to find it.

Chopsie

Any car I have had with a Manual Transmission does this. I now know why, thanks Allmotor!

fuzzy02CLS

iTrader: (2)

Don't know man. I felt the same thing in my auto when I had that. At least it was the same feeling. My 6 speed does it sometimes too.

Shawn S

I’ve been driving manuals since 1985 and this is the first car I ever noticed this on.

Shawn S

mrsteve

iTrader: (1)

Happens on my 5AT transmission from time to time as well. Usually about 1 mile down the road after leaving for work in the morning under light acceleration. Hasn't happened since the S/C install though.

N.O.6speed

Mine has done this since day 1. It only happens when the car isnt warmed up yet and I am just cruising. Im glad to know that it isnt anything serious.

Joe5.0

My car does this every once in a while too. It seems like it usually does it in 3rd or 4th gear when I'm at light throttle. It only happens when the car is not fully warmed up, but not when its still frgid, if that makes sense. I figured it was just a momentary CPU hiccup, and theres really no reliable way to explain nor show it to the dealer for them to fix. I fhave found that the CL-S does not like running cold AT ALL. It idles rough, accels non-linearly, and just has a general dislike for driving until the fluids are up to temp. I just let it warm up a little extra long than my other cars, and it seems to prevent any of the related quirks that are associated with colder temps.

DDT-TypeS

Are you guys referring to that "pre-warm up" jolt on the 6mt?

Man, I was about to go to the dealer to have it fixed or some shit because I thought it was the clutch acting up or something.

Whenever I start the car cold and head out, I have observed the engine temp gauge to be at 90-95% normal temp position is when I feel a sudden "jolt" like a "downshift" type of sensation. It is like when I didn't disengage the clutch properly..that type of feeling. It's not incredibly harsh but it's enough to startle me a couple times when cruising and the engine is not yet at 100% normal temp. I have observed happening everytime now when the car is cold. BUT only when I am IN GEAR and the car is moving I get the pre-warm up jolt. When the car is warmed up, I never get that jolt again. It's always at the predictable 90-95% warmup temp position (when looking at the engine temp needle).

I actually tried to prevent this from happening and sometimes it doesn't happen to me when I put the car in neutral and cruise allowing the engine temp to reach full 100% normal. But I can only get this to happen only a few times since the life of my car.

I guess this is normal because my old 01 cls at transmission kinda did the same thing...odd but I really hope this jolt doesn't get any worse with age.

ChadT

Seems like running the car at little higher RPMS when cold pretty much eliminates this phenomena. For me it does anyway.

Joe5.0

DDT that exactly what mine does, I dont think it warrants a dealership visit unless it is a violent jolt, or the engine turns off.