So I've been hesitant to post all this until I had all the info in front of me, to give you some insight I'm a master certified GM/Ford tech for the last 11 years, I own a small repair/tuning shop here in Oregon. My car is a 2014 2.0T with right at 26K on it (I drive a lot!) The car started exhibiting a bad idle and what I considered poor performance, after many trips to the dealer and after the last one me stating that I would gladly pay for a compression test! they finally performed a compression test and got the following. #1 122, #2 119, #3 120, and #4 52psi! So dead hole basically, and needless to say an apology for them beating around the bush. I would like to at least post my findings here so a few can have a heads up, the car never had a CEL or even any more than a few misfire counts while logging and those few it did find were only at idle. The car idled horribly and shook lightly but never stalled or really felt like it had a loss of power other than when you first hit the pedal, my thought is the turbo was taking up the slack of the last cylinder. I went to the dealership today and was able to get an inside look at the piston in question and the parts and take some notes.
1. The piston that failed, failed in the spot were the oil squirter is located, big question here is possibly the piston being over cooled in that area from cold oil causing it to fail? I know myself I always let the car warm before any spirited driving, but there have been a few times were I caught myself in a situation were I had to hammer to keep from causing an accident. Who knows?
2.The exhaust port for the number one and four piston to the turbo is easy to see smaller than the two and three port, as you can see from the pictures cylinders two and three are dirtier compared to one and four (other than the fouling on four), so another possibility is that manifold.
3.Coolant flow, As with any engine of this type the later cylinders receive warmer coolant and higher temps do to the simple design of the cooling system, front cylinder being the coolest and four the hottest. We demonstrated this long ago in many jeep 4.0 motors I built that we had to size the cylinders around the fact that the front cylinders ran cooler than the back.
4.Lastly is all speculation, I have seen from reading that most failures seem to be the last cylinder or the first cylinder, in the cases I have seen these two cylinders are always cleaner than the center two which leads me to believe that the issue is fueling or flow is different in these cylinders. My engine shows a clear indication of that along with the exhaust manifold showing that these two cylinders are restricted to some degree which would lead to higher temps and higher workload.
I hope someone can make some sense of all this soon, I'm one of what seems a few that really doesn't mind my car in the shop. I get a very nice 14 CTS to drive (which with how much I drive means a lot) and my service department is actually really on top of most things with my car and very accommodating. The only reason this one fought them is the observance of no CEL (service engine light) or any codes of any kind other than a few misfires. I think anyone with a rough idle and lagging power should have there car compression tested.
![]()
![]()
![]()
![]()
![]()
1. The piston that failed, failed in the spot were the oil squirter is located, big question here is possibly the piston being over cooled in that area from cold oil causing it to fail? I know myself I always let the car warm before any spirited driving, but there have been a few times were I caught myself in a situation were I had to hammer to keep from causing an accident. Who knows?
2.The exhaust port for the number one and four piston to the turbo is easy to see smaller than the two and three port, as you can see from the pictures cylinders two and three are dirtier compared to one and four (other than the fouling on four), so another possibility is that manifold.
3.Coolant flow, As with any engine of this type the later cylinders receive warmer coolant and higher temps do to the simple design of the cooling system, front cylinder being the coolest and four the hottest. We demonstrated this long ago in many jeep 4.0 motors I built that we had to size the cylinders around the fact that the front cylinders ran cooler than the back.
4.Lastly is all speculation, I have seen from reading that most failures seem to be the last cylinder or the first cylinder, in the cases I have seen these two cylinders are always cleaner than the center two which leads me to believe that the issue is fueling or flow is different in these cylinders. My engine shows a clear indication of that along with the exhaust manifold showing that these two cylinders are restricted to some degree which would lead to higher temps and higher workload.
I hope someone can make some sense of all this soon, I'm one of what seems a few that really doesn't mind my car in the shop. I get a very nice 14 CTS to drive (which with how much I drive means a lot) and my service department is actually really on top of most things with my car and very accommodating. The only reason this one fought them is the observance of no CEL (service engine light) or any codes of any kind other than a few misfires. I think anyone with a rough idle and lagging power should have there car compression tested.
