Shuddering When Accelerating...

[BayAreaSHO]

Recently I have been noticing a shuddering when I go more then a quarter throttle while in low RPMs in manual mode. Not quite sure if its the transmission, mounts, or AWD system. Any help would bee greatly appreciated. It feels like the car is rocking back and forth super fast and slightly

 

[mrhighcaliber]

Recently I have been noticing a shuddering when I go more then a quarter throttle while in low RPMs in manual mode. Not quite sure if its the transmission, mounts, or AWD system. Any help would bee greatly appreciated. It feels like the car is rocking back and forth super fast and slightly

Sound like spark knock. And the situation you declscribed is the perfect storm to force spark knock to present itself.

When was the last time you change your spark plugs?

When was the last time you changed your trans fluid?

I'm going:

#1 Spark Plugs (possibly coils)
#2 Transfluid
#3 mounts, etc



Sent from my PH-1 using Tapatalk

 

[BayAreaSHO]

Sound like spark knock. And the situation you declscribed is the perfect storm to force spark knock to present itself.

When was the last time you change your spark plugs?

When was the last time you changed your trans fluid?

I'm going:

#1 Spark Plugs (possibly coils)
#2 Transfluid
#3 mounts, etc



Sent from my PH-1 using Tapatalk

Spark plugs make sense. I havent changed them in about 6000 miles, and Ive had my car tuned without street dynoing it for about 2 months now to fine tune all the timing

 

[SHOdded]

Low trans fluid levels can cause all kinds of weird issues. As can a faulty ptu. and you won't have codes to help you either. checking the fluid level and condition in both cases, plus any signs of leaks at the axles etc should help eliminate some strong possibilities.

Would also check for chafing knock sensor wiring. Has reared its' head across gen 4 & 5, tho mostly gen 4.

Pulling the plugs gives you a quick honest eval of engine health of course.

What fuel are you running? Any changes in stations?

Doesn't sound like intercooler buildup being sucked into the intake, since you are in low boost conditions.

Are you stock or tuned? If tuned, return to stock and evaluate.

 

[BayAreaSHO]

Low trans fluid levels can cause all kinds of weird issues. As can a faulty ptu. and you won't have codes to help you either. checking the fluid level and condition in both cases, plus any signs of leaks at the axles etc should help eliminate some strong possibilities.

Would also check for chafing knock sensor wiring. Has reared its' head across gen 4 & 5, tho mostly gen 4.

Pulling the plugs gives you a quick honest eval of engine health of course.

What fuel are you running? Any changes in stations?

Doesn't sound like intercooler buildup being sucked into the intake, since you are in low boost conditions.

Are you stock or tuned? If tuned, return to stock and evaluate.

I will definitely check the trans fluid health. level is good though. I pulled the plugs and they all seem fine, the timing is also fine when I did a quick datalog to see how everything was functioning. Im running Shell 91 and have been for the lifetime of the car.
I am tuned, but when I did the data log, everything seemed fine, but I will retune it to stock and see if anything changes

 

[yaycandy]

Yea i had this happen when i was starting to lose compression in cylinder 2. Until it totally lost compression. Dont be scared. I doubt thats your case, but thats the only time i noticed it.

 

[abs]

Check your upper motor mounts. With 140k on my EB Flex, the upper mount on the transmission side was torn to shreds and was causing a lot of vibration under high torque low RPM acceleration.

 

[FiveLeeter918]

You said low RPMS in manual mode. What gear are you in? If you are 6th gear rocking 1100 rpm and you try to accelerate the car has a nanny built in to keep from overboosting at improper loads. Drop a gear and it should be fine, or stick to D and the car will adjust itself when you go to accelerate. Personally I don't accelerate unless the car is over 2000 rpm, so drop a gear and should be fine.

If not, check the issues above.

 

[BayAreaSHO]

You said low RPMS in manual mode. What gear are you in? If you are 6th gear rocking 1100 rpm and you try to accelerate the car has a nanny built in to keep from overboosting at improper loads. Drop a gear and it should be fine, or stick to D and the car will adjust itself when you go to accelerate. Personally I don't accelerate unless the car is over 2000 rpm, so drop a gear and should be fine.

If not, check the issues above.

it happens in every gear except 6th around 1500-3000rpms if i go WOT, the tune i have eliminated the downshifting if you floor it in manual mode, I talked to my tuner about it and he hasnt heard of my problem before, so I am going through checking everything.

 

[FiveLeeter918]

does the cel flash when it happens?

 

[BayAreaSHO]

does the cel flash when it happens?

No CEL, just a very noticeable amount of shuddering, it feels like im breaking something

 

[FiveLeeter918]

do you have the upgraded trans mounts?

 

[BayAreaSHO]

do you have the upgraded trans mounts?

stock trans mounts, i think it may be time for a new transmission, I was coasting in 1st today to hear the crackles and my transmission randomly surged up to 4k rpms from 2k

 

[SHOdded]

how does the fluid look? clean and free of debris? Except in special circumstances, I would suspect the electronic controls on the transmission (tss, oss, range sensors) and the torque converter first.

 

[ticoscen]

Torque converter slipping.