GMC Terrain

[CadillacCoupeMan]

Hello,

I have a 2012 GMC Terrain 3.0 litre with 230,000 km AWD. Its been running fine, then my wife parked in front of the driveway. I rolled it back (in neutral without starting the engine) just past the driveway. The next day it refused to start and still will not start. I had a mechanic come out and do a diagnosis. He said it had power, spark, fuel pressure, fuses were good but compression was low ( he checked the front bank of cylinders .. 90-60-90 psi). He didn't do anything else.

The starter is turning, engine just won't fire.

Is the low compression the reason it doesn't start, as he said? Am I looking at engine replacement or a valve and head repair/replacement?

Thanks

[Stealthee]

I'm wondering if when you rolled it backwards you didn't cause the timing to get slack and jump time. Would explain the poor compression and no start.

[CadillacCoupeMan]

Thanks Stealthee,

I don't know much about timing chains, aside from their function.
If the chain did jump, can it be reset or do you think the valves
got bent as a result of improper timing? Bearing in mind that it
never fired while I was cranking it.

[Stealthee]

Just cranking with timing being wrong can cause bent valves on an interference engine if it is off enough.

[CadillacCoupeMan]

Thank you Stealthee