RPM Surge
Thread Starter
4th Gear
Joined: Jun 2024
Posts: 4
Likes: 0
From: Oregon
RPM Surge
Hi everyone, I'm the second owner of my 1999 C5 it has 117K miles. after owning the car for 4 years I've noticed the RPM have started to surge right around 1500rpm and then again @ 2000 RPM but only in 3rd gear or overdrive. no codes. I've read a few different threads regarding the RPM Surge and what maybe causing it (MAF, Throttle Body) so I cleaned the throttle body and MAF sensor. however, I still have this issue.
I notice that at low speeds the car will shift to the next gear just above 1500 RPM. then once in 3rd gear or overdrive the surge then starts. the tack drops about 200 RPM the recovers. this happens over and over again till I raze the RPM to 1700. But then it starts surging again
Any thoughts on what may be causing this.
I notice that at low speeds the car will shift to the next gear just above 1500 RPM. then once in 3rd gear or overdrive the surge then starts. the tack drops about 200 RPM the recovers. this happens over and over again till I raze the RPM to 1700. But then it starts surging again
Any thoughts on what may be causing this.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
What you are describing as surge appears to be transmission slip, and / or erratic shifting or converter lock-up. Do you have the same symptoms when you shift it manually? Have you checked the transmission fluid level?
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
Thread Starter
4th Gear
Joined: Jun 2024
Posts: 4
Likes: 0
From: Oregon
After doing some testing and plugging in a reader this is what I found.
With the car in park and neutral I was not feeling the surge due to it only being about 50 rpm drop but it is there.
Shifting manually still getting the surge. if I'm accelerating it does not happen. only when trying to cruise through town at 36-60 mph with rmp @ 1400 and again @ 1900.
transmission fluid, no leaks, level is good. car was in park on a lift. fluid temp was with in specified range.
With the car in park and neutral I was not feeling the surge due to it only being about 50 rpm drop but it is there.
Shifting manually still getting the surge. if I'm accelerating it does not happen. only when trying to cruise through town at 36-60 mph with rmp @ 1400 and again @ 1900.
transmission fluid, no leaks, level is good. car was in park on a lift. fluid temp was with in specified range.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
After doing some testing and plugging in a reader this is what I found.
With the car in park and neutral I was not feeling the surge due to it only being about 50 rpm drop but it is there.
Shifting manually still getting the surge. if I'm accelerating it does not happen. only when trying to cruise through town at 36-60 mph with rmp @ 1400 and again @ 1900.
transmission fluid, no leaks, level is good. car was in park on a lift. fluid temp was with in specified range.
With the car in park and neutral I was not feeling the surge due to it only being about 50 rpm drop but it is there.
Shifting manually still getting the surge. if I'm accelerating it does not happen. only when trying to cruise through town at 36-60 mph with rmp @ 1400 and again @ 1900.
transmission fluid, no leaks, level is good. car was in park on a lift. fluid temp was with in specified range.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Drifting
Joined: Jul 2004
Posts: 1,659
Likes: 684
From: Pingree Grove IL
Do you have a Vararam intake by any chance. I had RPM surge after installing the VR in about that same RPM range. More surge on deceleration. I learned the VR intake connections need to be extremely tight so there are no air leaks.