Tim, thanks for the video. I had a couple of comments...You can switch the units on the Tech2Win from Celsius to Fahrenheit using the 'UNIT' soft key. 75* F is easier to read, at least for me.I'll make an assumption that the only DTC stored was a P0300? I normally would go into the misfire data screen to determine what cylinder(s) are missing. Are there history misfire counts stored for all cylinders? Cylinders on Bank 1, Bank 2? Cylinder 2 only? I'd also look at Fuel Trims, STFT & LTFT. The vacuum leak that you fixed, I would expect positive numbers for both the STFT & LTFT. Did the ECM fuel trim corrections correct the 'rough running', or did the intake manifold start to seal as the engine warmed up. My guess was the fuel trim correction was the reason why the engine smoothed out. What caused the OEM gasket to fail? A spark plug replacement and the gaskets were not replaced?I'm with Jim on this, no torque wrench?
Scott - Correct, yes the units can be switched on the Tech 2 from Fahrenheit to Celcius and vice versa (we kept ours that way for the video because the focus was not on temp as much as it was on the Fuel Trim info, and because, at the time, our interface that we were using would drop half the PID list if we commanded the swap). Great comments and spot on. You can go to the History Misfire counts and identify the offending cylinders, only once a DTC P0300 sets on GM platforms. We knew the intake was leaking because it was audible (whistled on a cold start). From that point, it was clear it was on Bank 2. We were not too concerned on cylinder Misfire I.D. at that point as much as we were in discussing Fuel Trim corrections. Although, you raise good points and very valid diagnostic routines. I think you are spot on in your diagnostic routines and would not change a thing. Correct, the PCM learned the fuel corrections once the engine went into Closed Loop operation, from that point the engine would then smooth out. It was also noticed on this failure that the engine would run smoother when warm, something we have seen to be fairly common with intake gasket ‘air’ leaks. Correct, most of the time air leaks will cause Positive fuel trim corrections on vehicles using MAF (Mass Air Flow) sensors. On vehicles using Speed Density fuel injection and MAP (Manifold Absolute Pressure) sensors, instead of MAF’s, you would expect to see the opposite (Negative FT corrections). The torqueing of the fasteners did not make the video, but we can assure you we torque all engine fasteners during gasket repairs and installations. The battery powered ¼” drive electric wrench was only used to run the fasteners down. It was not the final step of the tightening process. The purpose of that particular video was mainly about using Fuel Trims to diagnose air leaks, not so much on proper intake manifold gasket replacement (although we should have thought far enough ahead to include that). Also, the gasket failed because the embossed rubber O-ring had flattened and no longer made a good seal.
Hey I have a 2009 3.6l And the 02 sensor is filled with oil seems like car run hot then this happen takes about 3 month for the new senseor fills....this is bank 2 sensor 2
This video was a Godsend, Thank you!
Thanks, short and simple. Much appreciated.
Hey Tim, Great Job !!! This is Roger Bentdahl . Keep up the wonderful videos.
Tim, thanks for the video. I had a couple of comments...You can switch the units on the Tech2Win from Celsius to Fahrenheit using the 'UNIT' soft key. 75* F is easier to read, at least for me.I'll make an assumption that the only DTC stored was a P0300? I normally would go into the misfire data screen to determine what cylinder(s) are missing. Are there history misfire counts stored for all cylinders? Cylinders on Bank 1, Bank 2? Cylinder 2 only? I'd also look at Fuel Trims, STFT & LTFT. The vacuum leak that you fixed, I would expect positive numbers for both the STFT & LTFT. Did the ECM fuel trim corrections correct the 'rough running', or did the intake manifold start to seal as the engine warmed up. My guess was the fuel trim correction was the reason why the engine smoothed out. What caused the OEM gasket to fail? A spark plug replacement and the gaskets were not replaced?I'm with Jim on this, no torque wrench?
Scott - Correct, yes the units can be switched on the Tech 2 from Fahrenheit to Celcius and vice versa (we kept ours that way for the video because the focus was not on temp as much as it was on the Fuel Trim info, and because, at the time, our interface that we were using would drop half the PID list if we commanded the swap).
Great comments and spot on. You can go to the History Misfire counts and identify the offending cylinders, only once a DTC P0300 sets on GM platforms. We knew the intake was leaking because it was audible (whistled on a cold start). From that point, it was clear it was on Bank 2. We were not too concerned on cylinder Misfire I.D. at that point as much as we were in discussing Fuel Trim corrections. Although, you raise good points and very valid diagnostic routines. I think you are spot on in your diagnostic routines and would not change a thing.
Correct, the PCM learned the fuel corrections once the engine went into Closed Loop operation, from that point the engine would then smooth out. It was also noticed on this failure that the engine would run smoother when warm, something we have seen to be fairly common with intake gasket ‘air’ leaks. Correct, most of the time air leaks will cause Positive fuel trim corrections on vehicles using MAF (Mass Air Flow) sensors. On vehicles using Speed Density fuel injection and MAP (Manifold Absolute Pressure) sensors, instead of MAF’s, you would expect to see the opposite (Negative FT corrections).
The torqueing of the fasteners did not make the video, but we can assure you we torque all engine fasteners during gasket repairs and installations. The battery powered ¼” drive electric wrench was only used to run the fasteners down. It was not the final step of the tightening process. The purpose of that particular video was mainly about using Fuel Trims to diagnose air leaks, not so much on proper intake manifold gasket replacement (although we should have thought far enough ahead to include that).
Also, the gasket failed because the embossed rubber O-ring had flattened and no longer made a good seal.
Hi Tim. Nice video. Thanks Tim Heritage
Great explanation!
While you have the upper intake removed always replace the rear spark plugs.
Where does that sensor connect to? The one with the blue o ring around it that starts from the back of the motor?
What is the official name of that ? i know the one to the right if your in front of the car is a vacuum hose
Hey I have a 2009 3.6l And the 02 sensor is filled with oil seems like car run hot then this happen takes about 3 month for the new senseor fills....this is bank 2 sensor 2
It’s me or he is confusing the upper manifold gaskets for the lowers 🤔
The plenium (upper) manifold is NOT the LIM( lower intake manifold) which prone to leaking on all these gm 60° V6