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sprinkles08
sprinkles08, ASE Certified Technician
Category: Chevy
Satisfied Customers: 21591
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
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I have ever a 07 malibu with a 2.2 4speed auto. I have no

Customer Question

I have ever a 07 malibu with a 2.2 4speed auto. I have no power on acceleration. Free Rev in park it hits 4-4500rpm rev limit. But power brake ingredients it only hits 2000ram. When I put it in low to shift my self it starts off in 3rd not in 1st.
Submitted: 4 months ago.
Category: Chevy
Expert:  AMEDEE replied 4 months ago.

Hello and welcome! My name is ***** ***** I can assist you with your question. Can I start by getting the codes in the computer? Thank you!

Customer: replied 4 months ago.
That's the thing it's not setting any codes
Expert:  AMEDEE replied 4 months ago.

How did you check for codes? What tyep of scanner did you use?

Customer: replied 4 months ago.
My autel maxi Das. I'm a mechanic myself I'm just stumped by this one. If it helps the car sat for about 6 months due to a broken timing guide and I fixed and now this
Expert:  AMEDEE replied 4 months ago.

Maybe the timing chain was installed incorrectly. What is the engine vacuum at when the engine is at idle?

Customer: replied 4 months ago.
Timing seems fine. I did it twice due to the fact I thought the same thing. But I will check vacuum.
Customer: replied 4 months ago.
15 inhg at idle and 16 at 2500 rpm
Expert:  AMEDEE replied 4 months ago.

The engine vacuum is WAY TOO LOW. Either the timing chain is not installed correctly, the exhaust is plugged or you have a MAJOR air or vacuum leak.

Customer: replied 4 months ago.
Sticking steady around 16.5 at idle after a min or so
Expert:  AMEDEE replied 4 months ago.

It should be closer to 20 inches at idle

Customer: replied 4 months ago.
What about the trans reading 3rd gear when I put in into low to manually shift it? And the timing is 100% on could it b something else. I don't want to remove it again just to be back at point a.
Expert:  AMEDEE replied 4 months ago.

The transmission is controlled based off of the engine performance. The engine needs to be fixed first.

Customer: replied 4 months ago.
The transmission is electronic controlled. I understand the engine part. But the trans reading 3rd gear at all times is an issue I Will have no power on take off starting in 3rd
Expert:  AMEDEE replied 4 months ago.

Are there any transmission codes?

Customer: replied 4 months ago.
No. There is not.
Expert:  AMEDEE replied 4 months ago.

Usually it will set a code. But if not, and your sure it is related to the transmission, my experience has been that this is caused by a bad shift solenoid or a bad valve body.

Customer: replied 4 months ago.
Also any where I find the good running vac is 17 to 20 inch hg. And a wot snap sends below 5 inhg and rebounds to 20 or so and that's exactly what I'm getting. I don't think the timing or vacuum is an issue.
Expert:  AMEDEE replied 4 months ago.

Can upload a picture or video of the vacuum needle with the engine running?

Customer: replied 4 months ago.
some time today I can.
Expert:  AMEDEE replied 4 months ago.

Sounds good!

Customer: replied 4 months ago.
I can do a pic now if I can figure it out
Customer: replied 4 months ago.
This is at idle
Expert:  AMEDEE replied 4 months ago.

Thank you for sending the pic! The engine vacuum is too low. It needs to be closer to 19 or 20 inches

Customer: replied 4 months ago.
2 inhg. If timing was uff it would b more substantial than 2. What are other causes. Also I noticed then in drive watching app and tps sensors the app says 100% wile tps says 34 to 38 %. Should enter they read the same
Expert:  AMEDEE replied 4 months ago.

other causes for what? Low power or low engine vacuum?

Customer: replied 4 months ago.
Guess both. But is 2inhg really going to cause this
Expert:  AMEDEE replied 4 months ago.

YES, this is a major issue. If the engine cant breath, it will not produce power. In addition, if you have a transmission issue, it will not accelerate properly. I would fix the engine performance issue first and then move on to the transmission issue if needed.

Customer: replied 4 months ago.
Any ideas what to check on engine ? Just normal vacuum leaks? If the compression is good on it and good as in 125-130 psi all 4 cyl the valves are good correct. Cuz I know a burnt valve can lead to low vacuum
Expert:  AMEDEE replied 4 months ago.

Just because compression is good does not mean the valve timing is correct. It can be a tooth or two off and still have compression.

YES burned valve will cause low or no compression on ONE cylinder. But it will not cause low vacuum like you have. It will cause the vacuum needle to fluctuate as the engine is running.

Restricted intake, exhaust valve timing, vacuum leaks or incorrect valve timing can all cause low engine vacuum.

Customer: replied 4 months ago.
But I have stated I have doubble checked timing even remover the whole timing set and replaced it. Lined the makes up with colored chain marks and marks on new gears. Timing is 100% good. I'm sure of it
Expert:  AMEDEE replied 4 months ago.

Ok good. That leaves the other things I mentioned.

Customer: replied 4 months ago.
Other question is I have a 05 cobalt 2.2 that has 15 inhg and runs perfectly fine. And a 02 civic with 16 that runs perfectly fine. I think my vacuum is fine. I feel this is no help for the 30 some odd dollars. Is there a way to have someone else chime in on this
Expert:  AMEDEE replied 4 months ago.

You bet! I can leave this open for other experts. Good luck!

Expert:  sprinkles08 replied 4 months ago.

Hello and welcome to JustAnswer!

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