GMC Acadia Forum banner

1 - 20 of 38 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
My Acadia has just over 2000 miles and has just started doing this. When its cold, and only when its cold, when we start it up the engine rapidly alternates from a low rpm to a higher rpm, and keeps going back and forth. It stops doing it when you put it in drive or reverse.
Anyone hear about this? Haven't had a chance to talk to a dealer about it yet. :(
 

·
Registered
Joined
·
119 Posts
With our Montana, when it's cold starting (like starting in the freezing Canada winter cold), it starts off at a high RPM, then as the engine warms up if revs down to a lower RPM. I hear it sometimes go higher and lower, which is probably normal, but how often does yours alternate?
 

·
Registered
Joined
·
115 Posts
I noticed this again today -- it was around 28C here, yet when I remote-started the Acadia the engine was really racing.

I'm sure the outside temp in the DIC read at least 35C (always off till I drive for a bit, kinda like the gas tank when parked on an incline issue); so the car didn't think it was cold out!

Something to discuss at the dealer if I get up early enough tomorrow to take it in...
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #4 ·
The problem I'm having is not the typical cold start high rpm until the engine warms up. This is a rapid back and forth, low-high-low alternating change in rpms, changing about every second! I called a dealer today for an appointment and the guy in the service department said coincidentally that another Acadia was brought in last night for the same symtom. He said they started it up today (cold) but it did it very briefly, then was normal. Left no record of a service code either in the computer, he said, and they had not been able to figure out why its happening yet.
Help anyone????
 

·
Registered
Joined
·
17 Posts
Is it possible that the a/c (auto, or, manual mode) was left in the "on" position after the previous driving cycle, thus causing the a/c compressor to engage immediately ? Just a thought.
 

·
Registered
Joined
·
22 Posts
My Acadia revs up irratically during a cold start (Sitting over night). I brought it to the dealership and they said it was bad fuel. They dropped the tank, flushed the fuel and added an additive to the new gas. It corrected the issues for 2 weeks until I filled up again. GM says it is the blend of fuel from winter to summer? Anyone has a resolution for the problem?
 

·
Registered
Joined
·
428 Posts
The a/c is not the curlprit. The compressor would have to be kicking in and out every second to cause what they are describing. That would burn the compressor up. Also with the remote start you are supposed to leave the a/c on so when you remote start the car it cools off the inside before you get in.
 

·
Registered
Joined
·
428 Posts
By the way for the compressor to kick in and out like that it would have to be low on freon which means it would not cool the car.
 

·
Registered
Joined
·
22 Posts
I'm bringing mine to the shop Wednesday, GMC said tech bull. PIP3146B covers such a senerio but blames it on bad gas. I use only Shell gas. I looked under every forum around and can only find 2 others with similar problems but I can get in touch to see if they resolved the issues. This vehicle wemt one year with not a problem and now I have one GM can't fix....
 

·
Registered
Joined
·
15 Posts
We were having identical symptoms. Mossy GMC in New Orleans could not fix; tried reflashing computer. Out of town dealer where we bought the car said to bring to them and they would fix or replace. They had car for a week and it never acted up. Very wierd. We got the car back and it was fine for a week and then it started the problem again, although less serious. Let's keep each other updated and see what GM does to repair.
thanks
 

·
Registered
Joined
·
22 Posts
It is currently at the dealership at Don Bohn and they are reporting bad gas again....GM says it is the gas produced in the SE area with higher than normal alcohol content due to mass production. I only use Shell 87 octane which has switched over to 10% ethanol lately. I have used this gas for a year and now the problem. The puzzling thing is that when Don Bohn drained the tank flushed it and added an additive the car rain fine for 2 weeks and then I filled up at Shell again and the very next day the problem came back...
 

·
Registered
Joined
·
8 Posts
Hiya from the new orleans area myself ;D

I just got my '08 acadia about 2 weeks ago and only have 800 miles on it but i'll let ya know if it starts acting up...........I hope don bohn figures it out on yours because thats where I bought mine from lol
 

·
Registered
Joined
·
8 Posts
GRRRRRRRRRRRRRRRR............... :angryfire:

I should have never read this thread............I went outside and the truck had been sitting overnight...........tried the remote start and sure enough............crazy surging idle............i mean ................what the hell..........i shut off the car and started it with the key and no issues what so ever
 

·
Registered
Joined
·
22 Posts
It does not seem to matter if you use the remote or the key. It's when it sits over night. A mechanic at the dealer was listening in and he said "water in the fuel". I stated that why only my vehicle and not everyone else? I think this is a fuel issues and GM does not know how to handle it. I called GM today and they say it is the fuel blend in the SE region. I say tell me why it only effects some Acadia's not all of them.
 

·
Registered
Joined
·
8 Posts
Anthony3 said:
It does not seem to matter if you use the remote or the key. It's when it sits over night. A mechanic at the dealer was listening in and he said "water in the fuel". I stated that why only my vehicle and not everyone else? I think this is a fuel issues and GM does not know how to handle it. I called GM today and they say it is the fuel blend in the SE region. I say tell me why it only effects some Acadia's not all of them.
well i'm going to let it sit overnight and start it with the key........its never did that with the key ever......and i rarely use remote start...........dunno lets see what happens
 

·
Registered
Joined
·
22 Posts
Just got mine back from the dealer. They say GM vehicles and Fords are reporting the problem and the gas was sampled to show to much Alcohol...GM is working with engineers to find a fix probably a computer issues.
 

·
Registered
Joined
·
22 Posts
Well, I conducted my own test and have figured out that the Acadia's do not like high ethanol fuel (10%). After the problem with an erratic idle upon cold start continued I researched and found out that ethanol actually reduces the octane by 1-2 %. So, I decided to add five gallons of supreme gas to a tank of regular and poof! the problem went away. I called GM and they said I'll have to wait until the refineries in the SE region change the ethanol blending. I said what if they don't what is GM going to do, this seems to be a reprogram issue that GM engineers can handle and I was told that GM does not fix fuel issues, it has to be the gas stations. So I now have an Acadia that will not run properly on regular gas.
 
1 - 20 of 38 Posts
Top