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Trembling at idle

182K views 525 replies 136 participants last post by  goofygoober 
#1 ·
My 2.0T has a tendency to tremble at idle. I've switched to premium gas with no results. Also it doesn't alway happen, very irregular. Any ideas?
 
#130 ·
This may have something to do with the software (programmer for over 40 years). When designing a large program, the software has to go through a loop for the constant rechecking of all the systems that it is designed to monitor. If there are a number of subprograms that the program must check and recheck, then there will be a delay. This delay may be what is causing this idle problem. Therefore, if it takes a bit of time to check the operation of the engine at low RPMs, a stall may start. So, if this number drops below 800 rpms then performance can suffer while the program resets the engine operation. I have had this problem too.
 
#138 ·
@Dave623 -- no kidding about the dealer, looks like we purchased the car from the same dealer :)

@cathycpc -- can you kindly to post the details of the update so I can go to my dealer and request them to perform the same ECM update? It would be great to show the exact work order line item description from your invoice that will help them. Not sure ECM firmware is same since yours is 2.0T and mine is V6 but I have the same identical issue and hoping that there will be a update for my ECM as well.
 
#175 · (Edited)
Ok, since I had the ECM updated, we have NOT had any more hiccups (feels like a misfire). However, the generalized trembling at idle seems to have gotten worse. I'm not sure if it is as simple as the idle being set too low. For example, I can get the tremble to go away if I hold the brake down with my left foot to keep the car stopped and slightly press the gas peddle with might right foot to bring the RPMs up a little.

Any private tuners want to provide input here? Maybe there is a software tweak that can be done cheaply to raise the idle RPMs slightly. I would pay for that. The fix from GM might take a while... corporate bureaucracy and red tape... :thepan:
 
#137 ·
I can say that my car idles a hell of a lot better after my oil change. I had it done at 1k miles as I never like my car to go too long with the original oil in it. Old school I know but it has not failed me yet. I noticed a vast improvement in overall smoothness. However, that could just be a placebo effect. Time will tell.
 
#139 ·
Would you believe I still can't get a firm answer on which engine the idle calibration update is for? This issue has been reported with all three engines and it would be nice if it was finally put to rest -- six months of shaking is enough. Perhaps one of the Caddy Customer Service folks who frequent the forum can do some investigating?
 
#140 · (Edited)
For me it is close to 3 months and I am tired of it. My dealer and the GM district support specialist I spoke with keep saying its harmless. I am not an auto mechanic, but I am afraid that it may be damaging the motor mounds with this constant shaking. You are correct, it is reported on all engines. Based on various posts here and here it is definitely on V4 turbo and V6 engines for sure. Pretty much most if not all V6 have this problem but the effect is not as dramatic as some of the V4 owners reported. According to one post here, it may be as a result of very aggressive idle tuning (very low rpm at idle?) by GM/Cadillac to squeeze out most mileage. It sounds like they could be right...my car idles around 450-500 rpm (it is approximate but I am going to measure with OBDII accurately over this weekend). After some google search, it appears that passenger car idle rpm should be between 600-1000 depending on engine type so definitely this is low and could be the reason.
 
#141 ·
@aselvan -- With my 2.5 engine, the tremble, since day one, has been light to moderate. In the past month, it kicked up enough to cause a stall on three occasions. Idle is around 700 rpm routinely and the shaking even occurs when first starting the car and idle's around 1000 rpm. On the other side of the coin, there are times when the idle is around 500 rpm and it's smooth as silk.
This issue does not create any computer codes and my dealer's response to every issue I've had since last December (and still
occurs) is "we need a code" and/or "we can't do anything if we can't reproduce the problem". It's getting very old.
 
#143 ·
Wow I thought I was also just being picky, the other day I noticed my seat moving when I take turns, turning out after reading on here that many people have the same problem...... Then recently noticed just a bit of a stumble at idle especially when cold and, once again, upon reading here, many people seem to have had the same issues! Admittedly I did not read all posts in thread, but has anyone mentioned stretched timing chain?? Someone I know who works for gm told me these engines have had a problem with timing chains that first shows up as rough idle and may show a misfire code. I dont know about you guys but for a $50,000 car, I expect it to idle smooth as glass and my seat to be solid as a rock!
 
#144 ·
@bluecrayon -- welcome to the party :bigroll: Problem is, the tremble has been reported with all three engines and even with a stall, there are no computer codes. And, the degree of tremble is all over the place. Lots of people don't have it at all. There is an SPS update for idle calibration for the turbo (my dealer says it's for the 6 cylinder). So far, nothing for the 2.5 engine. BTW -- I've now stalled four times and this coupled with numerous on-going electrical issues, I sent an email to Cadillac this afternoon requesting a field engineer. Bottom line -- after six months and a clueless service department, I want the car fixed or replaced.
 
#147 ·
If this issue "was normal" for a 4 cylinder, there wouldn't be a technical service bulletin out, nor would that explain why some
ATS's do not have the issue and others have it ranging from mild to severe. Sounds like your dealer is like mine. I appreciate
the fact that the ATS is a new animal and will have gremlins. But, one would think, with all Cadillac has riding on this vehicle
and their public relations image, they'd bend over backwards to get things fixed. BTW, Cadillac Customer Assistance just called me. My six months' worth of electrical issues and the worsening tremble are now in the hands of a District Specialist. We'll see what happens.
happens.
 
#148 ·
I am working with a district specialist as well for the past several weeks. According to them, GM keeps telling them its 'normal' and they are echoing back the same to me ... it is frustrating. They insist that I take my car to the dealer who keeps telling me there is no fix. [I am taking it anyway this week, but pretty sure I am going to get the same response].

I am just wondering since there are enough of us with this problem, is there anything we all can do collectively to take this w/ GM directly instead of working with your respective dealers who seem to be clueless? Luckily for me, this is not as bad as some of you but still makes me very mad --- we are talking about $40K+ car here not low end.

Other than this problem and few CUE issues, I love this car and it is so awesome to drive this!

----------

I had the ECM update performed last week and no hiccups so far. :thumbsup: I'll let you know if they return...
@probee773 can you please share the details of this ECM update? Is your ATS 4T or V6?
Thanks
 
#149 ·
@aselvan -- does GM think we're idiots? TSB's are not issued for something that is normal. There's a TSB for the tremble --
it is not normal. If enough people file complaints with the NHTSA, it could potentially lead to a recall and I don't think GM would
want that for 'the car of the year'.

I got Caddy involved because of electrical issues since day one. Yesterday, after six months, I was able to duplicate one of the
issues for my service consultant and a tech even managed to duplicate it. They still have no idea of what's going on with my
ATS. And now, they're even telling me the Powertrain Control Module is shutting down and losing memory and I don't have any
powertrain issues and that has nothing to do with the electrical issues. It's going to come down to a field engineer who will
either find the problems and fix the car or authorize a swap or buy-back. I love the car but I'm totally fed up. Not a good
first Cadillac experience.
 
#151 ·
Laura,

It appears that we all have the same issue at different levels (i.e. mild/medium to pretty bad shaking) regardless of the engine type (4T, or V6). I am sure you and other customer service reps in this forum heard about all of these by now through private messages.

At this point, I'd kindly request you guys to reach out to someone in GM/Cadillac who can help us instead of telling us 'this is normal' which is ridicules. Most importantly, few people here got some sort of ECM update which apparently got this problem fixed. Can we get details of those so we can go to our respective dealers and guide them to get our car fixed? Last but not least, please do some research to find out the status of the TSBs below (i.e. could possibly be 'the' problem we all experience) and let us know what needs to be done or at least tell us when we can expect a fix if there is no fix yet.

http://www.automd.com/tsb/bulletin_b353282/
http://www.automd.com/tsb/bulletin_b351074/

BTW: These TSB's list these problems as 'intermittent' but that is not true, I can reproduce it every day especially when the engine is cool at start in the morning and while stopped at light every single time!

PS: Like I said on the earlier post, I really love this car... the driving experience is so awesome ... If Cadillac can address this problem soon before it ruins the car, it certainly can claim to be the 'car of the year'

Thanks
 
#161 ·
@Dave623 -- As per your request, here is an update on my car. Just got a call from the dealer saying there is nothing they can do at this time -- no surprise here. This time, they also said there is nothing wrong with my car -- this is a surprise. I guess these TSBs ( http://www.automd.com/tsb/bulletin_b353282 http://www.automd.com/tsb/bulletin_b351074 ) are created for no real reason. I am really tired at this point and don't know where to go. I am considering my options to seek help elsewhere.

Wish you good luck with your effort to get yours fixed.
 
#156 ·
Hello Laura,

I had my car in for power steering failure and asked my service writer to check on the tremble. He insisted it was not an issue since they ALL do it, which is hardly an acceptable answer. Mine is not as bad as some, but it is most certainly noticeable. I understand its a slippery slope to make blanket, public statements on the issue but please convey to your chain of command that this is indeed an issue and should be treated as such.
 
#157 ·
Hi torkibe,

Thank you for reaching out to me. I understand everyone's dissatisfaction and frustration with their ATS trembling at idle issue. We have been in contact with our peers on the product side of the house in regards to the customer concerns that have been expressed. If you would like to further discuss your issues, please reach out to me via private message.

Sincerely,

Laura M.
Cadillac Customer Service
 
#159 ·
Laura,
Just letting you know that my car is at the dealer now. I am not able to send private message because of some limit/quota.
Thanks
-Arul

----------

Laura,
Just letting you know that my car is at the dealer now. I am not able to send private message because of some limit/quota.
Thanks
-Arul
Hello Arul,

Thanks for letting me know! I appreciate it. I also wanted to let you know, I did call Greg and left a message for him to return my call. I do want to continue our interactions, so let me see if I have to clear out my private messages, or we can continue to interact via Email.

Regards,

Laura M.
Cadillac Customer Service
 
#163 ·
@aselvan -- the two TSB's indicate the issue is under investigation. Translation -- no official fix. However, what I cannot understand is how my dealer tells me there's an update for the 6 cylinder and the only update I know of is an idle calibration for the turbo. Sure are a lot of questions and frankly, my confidence is shot. Like you, I've got a lot of other issues. I created a case with GM/Cadillac and have already been in contact with a District Specialist. We'll see how that goes. You do have options.
 
#164 ·
Told by my dealer and district rep. I have to live with this bad Ats. So what good is cadillac customer service and that GM won't even help out this is fact I am very disappointed to say the least the 2.5l motor shakes stalls trembles Andthey want us to BUY AMERICAN. The service rep said to me today that his hands where tied and stated well we can't help you live with it. Or pay 40 to 50 more dollars a month for a turbo. I am shocked at such a statement.hey Laura or Greg. What's up with such attitudes against cadillac customers. Should I have to live with this issue or can you support me in getting a turbo which service claims is so much better and smoother. My car was 36785. I priced a turbo exact same options for 37595. And my dealer says still cant help out. So what's my options as I really like the car. But this 2.5l is really bad need help here not i am sorry answers. Thanks
 
#165 ·
First, there are numerous reports of rough idling turbos and V6s. So no reason to think changing engines will solve the problem.

Second, nobody could tell just based on forum posts if your car is any rougher idling than normal. I don't believe you are making anything up but since ALL engines vibrate some and there is no way to know what your tolerance is, it might help if you say what engines you test drove and whether you test drove your car before buying and whether the other ones you tested were any better or worse.

If you didn't test drive the one you bought, then its a shame because it could have saved you all this trouble. Yeah, you shouldn't have to test drive your car but you also shouldn't have to look both ways before crossing the street at a crosswalk with a green light. But its just prudent to do both because you never know when you'll get a bad engine or a runaway cement truck.

If you DID test drive your car, was it too rough for you or did it stall? If so, you should NOT have completed the sale and will have to endure some unpleasant times. Better to walk away.

If it and the other 2.5s you test drove were NOT rough, then clearly it's something Cadillac should fix.

If there really is a problem with your engine and Cadillac won't fix it, that's what lemon laws are for. Find the requirements in your location and start the process. Make sure the paperwork for dealer visits have the information needed for a lemon law case.

And unless you don't want the car for any other reasons, try different dealers. They aren't all the same. If your dealer's service department is substandard another dealer may be able to fix it. Remember the dealers are independent businesses. If they are incompetent or just don't like you, GM doesn't have immediate control over them. Even if your situation is entirely their fault, GM can't do much more to them than a professor of yours could do to you for messing up a minor assignment. So go to another dealer, no matter what. You have nothing to lose.

I tried to go back and look at your earlier posts to see if you had answered any of my questions. I recall that you had posted several times but not specifically what you said. Curiously, search says you have NO posts but a post count of 1. I hope that's just a data base glitch and the admins aren't wiping out posts that are critical of GM or dealers. The latter would not make sense though since there is a specific forum here for dealer reviews and many of those are negative. AND there are lots of posts from people unhappy with their car or GM although most of those seem to get resolved in time.
 
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