Cylinder misfire

KITA32

MEMBER
2009 CADILLAC CTS
3.6L
6 CYL
4WD
AUTOMATIC
163,000 MILES

My car as a misfire on cylinders 1, 2, 4, and 6. It also has crankshaft-camshaft correlation on bank 2 sensor A or B. My car runs terribly with constant misfire, I didn't have any problem with my car until Firestone changed my oil. I have had the coils and spark plugs replaced along with a new crankshaft sensor and camshaft sensor and my car still runs terribly. Any suggestions on what could possibly be wrong with my car?

7 Replies

KASEKENNY

MECHANIC
18,907 POSTS

Hi Kita,

Unfortunately, this seems like an oil control valve issue. How closely after the oil change did this happen?

If it possible that they used the wrong oil. If this happened the the actuators may be malfunctioning because they are run off of oil pressure.

If they used the correct oil then we need to use a scan tool and monitor the cam/crank sync state because if they say they are out of sync then we may need to have the timing checked on the chains and cams. I don't see how this would be related to an oil change so it may be just a bad coincidence.

https://www.2carpros.com/articles/how-camshaft-variable-valve-timing-works

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Thursday, August 1st, 2019 AT 8:10 PM

KITA32

MEMBER
4 POSTS

Hi Mr. Kenny,

This problem occurred right after the oil change. I took it to a mechanic the same day and he said he really think they put the wrong oil in my car. I called Firestone back and told them they put the wrong in my car and they said I could bring my car back to them to get a full synthetic oil change or they would refund me my money. At this point I'm beyond pissed. So I took it to another Firestone and they did the oil change and told me that the oil was overfull, and stated they don't see how that would cause my car to run the way it's running. My car was running great until they touched my car.

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Friday, August 2nd, 2019 AT 5:00 AM

KASEKENNY

MECHANIC
18,907 POSTS

Okay. Two things. If the oil is overfull it may not cause this. However, if the oil is wrong (which I suspect it was) then the oil control valve for the variable timing system will not function properly. Basically this system moves the camshaft forward and reverse to improve performance, fuel mileage, and emissions. When the oil is too thin or too thick it does not work right and is really the only thing that makes sense for what you are saying.

I would make sure you get it documented in the event there is another issue. Especially if the other store changed the oil with the correct oil and it is now operating properly.

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Friday, August 2nd, 2019 AT 6:19 PM

KITA32

MEMBER
4 POSTS

My car still not operating right so I just went head and dropped it off at the Cadillac dealership yesterday. Whatever is wrong with my car it's affecting my brakes. Thank you for giving me an idea of what could be wrong with my car.

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Saturday, August 3rd, 2019 AT 4:43 AM

KASEKENNY

MECHANIC
18,907 POSTS

Oh Wow. That is an odd additional issue. The only thing that I can think is the misfire is not allow the engine to build vacuum which will effect the brake booster. Please let me know what they find because I am curious what it was. Plus that information will help others that may have a similar issue. Thanks