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Discussion Starter · #1 ·
Good morning, new to the forum and seeking help.

I have a great Impala, it's a retired 2007 Police package unit. It has 136k miles, looks great and for the most part runs great. Please keep in mind that this unit has emissions bypassed (option in the Police package I understand).

So here is my problem, when driving my engine surges while holding the accelerator steady. I have noticed this doesn't happen right off the bat when it's cold out if that helps. So I have connected my scanner and show no codes. I have no choice but to continue to drive it.

This problem can happen at low and high speeds. I initially thought it was a TPS, but this vehicle doesn't have one I understand.

Any ideas ?? I would be more than happy to provide additional information if asked. I really want to get my "baby" back to 100% service. :hope:

Thank you in advance for your assistance :beer::beer:

Lakeborn ...
 

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How old are the spark plugs? Check for vacuum leaks. Need to have the fuel pressure checked. And have the exhaust flow checked to be sure the converter is not clogging up.

Unless this vehicle is drive-by-wire it has a TPS. Also it has the emission systems.

A scanner with live data feed can be a big help in diagnosing problems.
 

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It IS drive by wire, but it also has 2 tps's. both are inside the throttle body, and as far as I know are not serviceable. From my experience however, that is most likely the problem. New throttle body is between $260-300 and takes less than 10 minutes to replace, no programming needed.

That said, please check the other things mentioned first, since you really don't want to buy an expensive part if you don't need it.
 

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Lakeborn, would you consider working with a Chevrolet dealership about your concerns? I'm happy to assist if you would like me to schedule an appointment or follow up with them on your behalf. Please send me a private message anytime if you would like me to research further for you!

Best,

Katie
Chevrolet Customer Service
 

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Discussion Starter · #5 ·
How old are the spark plugs? Check for vacuum leaks. Need to have the fuel pressure checked. And have the exhaust flow checked to be sure the converter is not clogging up.

Unless this vehicle is drive-by-wire it has a TPS. Also it has the emission systems.

A scanner with live data feed can be a big help in diagnosing problems.
Good morning ... thank you for the info :eek:k3:

The spark plugs are new (within 4k). I installed BOSCH plugs. And yes, I misspoke about the TPS unit in the vehicle. There is a TPS, however, it is in the throttle body. So maybe replacing the throttle body is the way to go. I know it's the entire assembaly and not just the TPS like in some vehicles.

Thank you for the point of direction :)
 

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Bosch products should be avoided at all costs, it is possible that those plugs are the issue. Stick with NGK or Delco.
 
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Fixed?

Lakeborn - did you figure out what was causing your issue? My wife's impala is doing the same thing. Looking for possible causes.

Thanks
 

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Same issue, Surge

For the same issue mentioned above have done a series of minor repairs and diagnosis as time and money allow.
I have replaced:
-Spark plugs, cables coming soon.
-Throttle body.
-Camshaft positioning sensor, changed twice.
-Camshaft positioning sensor wiring harness (removed upper intake to access "soldered, heat shrink, tape, and loom" :eek:k3:.)...continuity check as well.
-(Also, Checked fuel injectors spray volume and are with the correct resistance 11 to 14 ohms :eek:k3:. Retaped all wires to injectors and CPS :eek:k3:.) No problems found there.

I will keep everyone posted once I find the problem. I will get a hold of a real time scanner and may need some assistance from you guys on the data I aquire.

The 1st problem, if I am not posting correctly, is that the car is surging at all speeds. 5,10,15,20-70,80... etc. Happens with the load of the transmission. 144,400 miles on the tranny. I change tranny fluild and filter every 50k, :beer:. Changed it earlier this time at 138,000 miles and the normal sludge on the bottom of the pan (was curious.)

The 2nd problem is after a 2 hour and 30 min 70 mph run the Camshaft positioning sensor throws the P0011 code and shift between 1st and 2nd and 2nd to 3rd are hard.
 

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Video on surge.

Not the best quality video focus was slow on reader.

Constraints low on fuel until Friday so I could not take it out on a test drive.

Had the car parking brake on and brake depressed. Transmission in drive. Reved up to 1500 rpm (surge continues) :dunno:. Found that the reading on the accelerator pedal sensor was stable. You can see the surge on the tach on the dash and on the live reader. Here is the link to the video.

 

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Discussion Starter · #10 ·
Lakeborn - did you figure out what was causing your issue? My wife's impala is doing the same thing. Looking for possible causes.

Thanks
Hi I'm sorry for the delay. Ok, so this is what I did. I replaced the Throttle Body ($200). Assuming that the TPS was bad. Well, that's not the issue. I am thinking that maybe it is the coil ?? I'm flustered.
 

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UPDATE: Surge Problem

Turned out to be the cam phase actuator on the passenger side of the engine. I wish I had an exploded view of the front of the engine earlier. Please reference the link for the 3.5 liter engine. Chevrolet Impala LS: My 2006 Impala 3.5 Flex has code P0011, - JustAnswer

Also, reference this link for removal and install procedure (3.5 Liter). https://www.dropbox.com/s/6ddxo7rzm...ge reflects the changes called out in TSB.doc

2006 turns out to be the 1st year that VVT is on an in-bore cam. Please see link. 3500 Engine Also Gets VVT Boost

Getting the car back from the GM service dept. today. Will keep you posted if the problem is solved.
 

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RE: UPDATE: Surging

77Impala, She cost me 1260 after tax.

But, it is back there this morning so they can replace the transmission cooler lines they bent when reinstalling the motor / sub frame. Free! and Free rental car... 2011 Impala

Historically the Used 18K original 06 LS car has cost me a small fortune.
1.) Replaced motor due to broken valve spring cylinder no 2. Replaced with used motor, bad idea do to the shear fact that I should have went with a new engine with benefits. A new motor would have cost me less in the long run. Could have had it replaced under warranty if the odometer did not say 100,103. Changed oil religiously with 5w30 mobil 1 full synthetic. Never red lined. Total cost 2,750.

2.) Discovered oil leak around the pan. Requested the dealer to replace the front motor mount, oil deterioration. Requested that the dealer find anything and everything that would cause the leak. I.E. All the way to the rear main seal if necessary. Only replaced oil pan gasket and motor mount. Total cost 1109 roughly. Still in warranty, but only in warranty for the explicit part. :giggle:

3.) Recently, oil leak from rear main seal not covered by warranty. The dealer had the car since March 21st, got it back yesterday, and returned it this morning. Only spent 71 hours to replace the rear main seal and cam phase actuator. :giggle: Total cost once again 1260. Guess what she is still surging....

Total cost excluding self maintenance/parts. 5119 dollars. New motor installed by the dealer would have costed 5270 with 5 year 100K warranty.

Surging as described in previous posts happens at all speeds. I will now replace the MAF sensor and injectors next, myself.

Bright side. Getting an overkill PCM. Paid 2 days ago.

Did some modification. Replaced stock air box with spectre air kit. Resonator pipe delete. Maganaflow 40 series muffler. All only for the sound I would presume.
 

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Update: No Surging

Hey folks...

Turned out that the dealership replaced the internal actuator (retaining ring). It was not the correct fix. They did not replace the pancake actuator (mentioned above.) I replaced it this afternoon. So far no surging, at all, at all, at all...:yahoo: Any more questions please reply.

Yours,
Gary.
 

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Hey folks...

Turned out that the dealership replaced the internal actuator (retaining ring). It was not the correct fix. They did not replace the pancake actuator (mentioned above.) I replaced it this afternoon. So far no surging, at all, at all, at all...:yahoo: Any more questions please reply.

Yours,
Gary.
As much as I hate fixing my cars, your above costs and remedies not solving problems by folks that are paid to do it "right" is what keeps me either somewhat active in repair, or just pissed every time something crops up.

I have the Tire Pressure monitor stuff not working in the 06, think it is the receiver, but just see $1000 being spent, and the alarm going off a day later, like last time someone messed with it.

Stay patient, Gary.
 

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Can the cam phase actuator go bad and not throw a code I was working on a car this weekend that is doing that. If you try to accelerate from a stop or a cruising speed it seems to bog down and if you put the pedal enough it will push past that dead spot, downshift and take off. It's not throwing any codes.
 

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Hey folks...

Turned out that the dealership replaced the internal actuator (retaining ring). It was not the correct fix. They did not replace the pancake actuator (mentioned above.) I replaced it this afternoon. So far no surging, at all, at all, at all...:yahoo: Any more questions please reply.

Yours,
Gary.
Gary - what is true name of this pancake actuator you replaced to fix the surging in the imapala? Mine is doing the exact same thing.
Please help - Dave
 

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Update: No Surging

Hey folks...

Turned out that the dealership replaced the internal actuator (retaining ring). It was not the correct fix. They did not replace the pancake actuator (mentioned above.) I replaced it this afternoon. So far no surging, at all, at all, at all...:yahoo: Any more questions please reply.

Yours,
Gary.
Thank you very much for posting, I had the exact same problem and your posts were the only one out there that actually solved the problem !!!! The VVT silinoid on the outside end of the motor $49 total from carparts.com 15 minutes to install only because I dropped the little star wrench tip I was using at least 5 times.
Anyway thank you for taking the time to post and post your updates !!! Appreciate it !!!
 
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