2015 FRS pulsing at low RPM's in 1st gear
 

I know what you're thinking... "Another noob who doesn't know how to drive a stick". Not exactly. My first car was a stick and I've driven them off and on for over 10 years now.

I am, however, still pretty new to this forum and I usually stick to lurking to get a good chuckle at the flame-sessions and use it as a resource for DIY projects. This has been bothering me for awhile now, but I thought that maybe I just needed to break the car in a little more... plus it became more evident yesterday so I decided to start a thread to see if anyone else is experiencing this situation. If this needs to be moved to the warranty/TSB section, let me know.

I was sitting in stop-and-go traffic yesterday when the issue became much more evident to me. I usually just keep it in 2nd gear and cruise slowly during traffic since 1st can be a bit rough, but I thought I would try 1st since traffic was worse than usual. I released the clutch smoothly and at around 5-6 mph (can't remember the RPMs) the car was pulsing (bucking, lunging, lurching, whatever you wanna call it) and it was noticeably bad. I'm pretty sure it would have been obvious even to a bystander. It felt like first gear when the engine is cold, but it was definitely warmed up. I thought that maybe I was lugging the engine so I eased it up to 12-13 mph and it still happened. Needless to say, I stuck with second gear the rest of the way home.

I've searched the internet for awhile now to see if anyone else has experienced this, and some people say it's normal for a manual, but others seem to think there is an issue. I've never experienced it before in any other manual unless I released the clutch a little too quickly when first learning the engagement point on a different car than I'm used to.

If anyone else has experienced this, or knows if this is a serious issue or not, I'd love to hear from you. My first oil change/tire rotation (use 'em while they're free right?) is coming up so I'm thinking about mentioning it to the head shop mechanic at my local dealership to see what he thinks as well.

'Preciate the help guys!

EDIT: I'll try to duplicate the scenario again today to get exact RPM's if that helps. I was too busy watching the tach needle jump up and down to notice exactly what numbers it was occurring at.

First thing I would question would be if the clutch was fully disengaged. If you go out and replicate it today, you may want to re-engage the clutch if it starts bucking again and then rinse and repeat. If it keeps doing it, that could be a problem.

The clutch in my old Lexus would chatter a bit if it didn't get a good grab on release - doesn't sound like what's going on with yours, but might be something to consider.

The last thing to consider would be the gearing. First on these things is a lot of gear - I'm typically shifting out at 10-15mph, if not before. Just trying to creep in first makes for a bit of a bucking ride as you're going nearly instantaneously from accelerating to engine braking. You may want to see if the car does it with a steady foot on the accelerator, trying to hold it at 10mph, instead of on/off/on/off as you may have been in traffic.

Good luck!

I have had a similar experience with my 2013. Usually during very slow stop and go traffic or start and stop type things. Also while going over multiple speed bumps. (and no I dont leave it engaged in gear while going over them) Its like the car has three different moods. When its cold it has a set of strange behaviors. When its slightly warmed up from driving a little bit everything seems perfect. And then after driving for the 30+ minutes straight on a hwy and everything is at optimum temperature some strange behaviors start popping up again. Idk this car can have a mind of of its own and ive been doing my best to ignore it so that I do not go insane..

didn't you make a thread about this before?

If not, sorry for mistaking.

I'll give you the same advice as on the other thread: have a competent person who is demonstrated in manuals drive the car with you in it.

A brilliant idea!

All the manual cars I've driven have done this, combination of drivetrain lash and ECU compensating for the oscillation in a non-optimal fasion, nothing wrong with your car and you already know the solution.

:cheers:

You can usually make this happen if you're not perfectly stable on the throttle pedal. As soon as it starts to happen, the act of the jerking causes your foot to move a little bit front to back which makes it just keep on going until you either completely let off the throttle or give it a good amount of gas to get out of the rhythm. It's not something to worry about and it can be cured by better foot control.

Does the car do it if you let the engine push the car forward? IE - no gas with the clutch released in 1st gear at the slowest speed possible.

I'll check that out today after work... Thank you for the helpful response!

Yep! Just the car's way of saying "come on let's go already".

Nope, not me. This is the first thread I've started.

I knew I would get a response like this one. No matter how much experience you have with manuals, someone will always think it's user error. If I hadn't had other drivers notice it as well, I wouldn't have posted it. What will it take to establish credibility that it's not just me? Do I need to pay Randy Pobst to come by and get behind the wheel so that we can eliminate the "user error" response?

Based on other posts I've seen from you, Koa, you seem like a very smart dude, and I'm sure you're just jaded from some of the other idiotic threads that people have started, but I can assure that I've done my research and tried out multiple ways of clutch engagement/disengagement combined with throttle application and I've managed to get the same results multiple times. That's why I decided it was worth a new thread.

I know what you mean... in the mornings and after work when the engine is cold, it seems to exacerbate the problem when I apply throttle because of what you're saying.

Yesterday, when I was around 5-6mph, I was applying little to no throttle. I'll try again today making sure I'm not using any throttle to see what happens.

Brother, I'm not trying to say it's user error. I'm trying to get you to explore the possibility that it can be user error. If a mechanic, a competent one that is demonstrated and understands what happens in a clutch system, can replicate the problem, then you now have evidence that is it NOT the user.

Deduction is powerful.

I will say that I used to have this symptom bad. I commute 100 miles a day in Washington's worst traffic (I405). I have since changed out diff/outrigger/tranny bushings, adjusted the clutch pedal, swapped the slave cylinder for Ultramaroon's 3/8 retrofit, and there is virtually no pulsing now. I couldn't get it to even if I tried (okay, a bit of an exaggeration, but it is VERY hard to induce the pulsing that was exercised quite frequently when everything was OEM). Like you, I've been driving manuals for just south of a decade and was confident it wasn't me.

Turns out it was me and also the car. The clutch point is weird on this vehicle, even with the adjustments I've made and mods I've done to help remedy it. I had to alter how I engaged first and drove in traffic... but even then, I got pulsing. The supplementary mods helped a ton.

That's what I was hoping. Being that it's my first new car, I've never had the luxury of warranty so I wanted to make sure I got it checked out if it really is an issue.

Good to know it isn't my girl acting up... just a normal occurrence. :thumbup:

My auto does something similar in manual mode when coming to a stop. From 5-0 mph it will be a little jerky on the final moments of coming to a stop no matter how gentle I am on the brakes. It only does it when the car is cold though, never once it's warmed up, so I've chalked it up to the transmission just not liking the cold very much.