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2015 Impala LTZ 3.6 LFX V6. 110k miles. Installed new iridium plugs 3 months ago. The car hesitates/chugs real bad under load. Can have cruise set at 75, start to go up a hill and it hesitates. Give it a little too much gas at a red light and it starts hesitating. No hard or pending codes. Running at 1500 RPM there are 2-3 random misfires on different cylinders. Swapped a couple coils and plugs, no difference. Checked purge valve it is good. Smoke tested the intake using the brake booster vac line. Smoke out of the fowl air tube (PCV) at the intake. Line located on rear of motor. Replaced and still leaking a small amount. Seems like it needs to be a little thicker of an o ring. Has this been a problem for anyone else? The second leak is a big one out of the power booster vacuum located on the passenger side wheel well front. Would I have to block this off, or should it not be leaking? All other areas look good. Any thoughts or ideas why it is chugging so bad?
Off the top of my head I'd guess an intake leak is leaning out the mixture.
Is this a 2015 Impala Limited (2006-2015 body) or is it a 2015 Impala (2014-2020 body) ?
Did it have any issues before removing the intake manifold and replacing spark plugs?
What did you set the gap to on the new spark plugs?
How did the old spark plugs look when you pulled them out?
Originally Posted by Brooklyn
Brake booster vacuum on passengers fender well is sending smoke everywhere. Not sure if that would be normal or not. Would that have to be be closed off to perform the smoke test?
The brake booster is near the driver'*-side fender, so this smoke is coming from . . . ?
Originally Posted by Brooklyn
In park and hitting gas, there is hesitation and sounds like a large vac leak around the intake area. Not sure if that noise is normal since there is no smoke leak in that area.
It is the new body style Impala.
The smoke is coming from the Brake booster Vacuum located on the passengers side fender well. It is an additional vac pump that supplies the brake booster.
The old plugs looked very good and all very similar. I checked the gap and it was at .043. I did not have to regap the plugs.
The new plugs have been in the car for approx 2 months prior to this condition. We pulled the intake back off just the other day to look for visual cracks or issues with the gasket. I also, replaced the gasket to ensure it was not leaking.
The only leak we can locate is the air tube (PCV line) on the top of the intake. I replaced the tube and the new oring still does not seal real well. Not a very big leak. But I cannot think of a way to seal it, kind of a crappy setup
01-30-2022, 07:45 AM
2015 Chugging Impala
