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2007 Chevrolet Impala Repair Question


Topics covered: Gas, Sensor, Valves.
Mileage: 156,000 miles.

Asked on March 28, 2012

Non adjustable rockers

Can someone write out simply instructions for installing them, and if there's any tolerances that need to be checked. I'm simply asking this bc I have a valve train issue and valves not opening/closing properly. There is gas in the intake making me this its an intake valve issue. I just want some insight as to what I need to do/look for.

Compression is fine which has me scratching my head

I loose power as I'm cruising, going up hills I need to downshift or ill be going backwards, and when I hear the engine in the morning its noisy and feels rough, the car sometimes hesitates for a sec and revs up or it majorly hesitates and it needs like 50%+ pedal to pick up any speed. Lastly when letting off gas the rpms almost always jump a lil(positive its not trans)


Most notable to me is at idle as it will stay smooth at 750 then gradually sputter and drop to.like 525, then the engine just feels rough. I know none of this happened when I first got it.

PS I just want HELPFUL tips or suggestions, main goal is to set up a plan of attack to avoid a 100 shop diagnosis charge to find out that they are just ask F%&@IN confused as me.

Avatar Asked by pos07impala

Answer

Replied on March 28, 2012

You need to check the valve timing bc if its off the valves will open/close at the wrong time, also check the fuel pressure, EGR valve and the IACV to include the throttle position sensor-

Tiny Answered by rasmataz
68 questions asked
Replied on March 28, 2012

I don't think itsa t chain issue, since it doesnt missfire at all and it was never an issue before this, and fuel pressure constant at 58, this car has no egr or iacv, the throttle plates acts both as the iac and tps

Tiny Response from pos07impala
14 questions asked
Replied on March 28, 2012

I'm simply asking this bc I have a valve train issue and valves not opening/closing properly. There is gas in the intake making me this its an intake valve issue. How do you know this?

Also check the exhaust system for resriction-by doing a backpressure tests

Tiny Answered by rasmataz
68 questions asked

Replied on March 28, 2012

I replaced my map sensor on a lil.bit of a hunch(it did help) and when I pulled the sensor it was wet on the bottom, and to my understanding it can only be one of three things. Moisture gas or oil, and my plugs are all dry as can be so I didn't think it was oil, and it simply smelt like gas... So process of elimination really.

I just went for a drive and one light it idles fine no issue, next light the idle drops to 525 and feels as if its missing/stumbling its hard to tell but its def not a normal feel

Tiny Response from pos07impala
14 questions asked
Replied on March 28, 2012

Try cleaning out the throttle body and see what happens

Tiny Answered by rasmataz
68 questions asked
Replied on March 28, 2012

Ugh I'm probably going to have to take it in somewhere in town, everything people tell me to check iv checked over like 100 times the only thing I haven't done is a cylinder Leakdown test, which I will probably do unless some miracle arises and god comes down from the heavens to tell me what I did wrong ha

Tiny Response from pos07impala
14 questions asked