GMC Terrain
CadillacCoupeMan
07-22-2021, 11:09 AM
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
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
07-22-2021, 02:19 PM
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
07-26-2021, 02:11 PM
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.
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
07-26-2021, 04:37 PM
Just cranking with timing being wrong can cause bent valves on an interference engine if it is off enough.
CadillacCoupeMan
08-06-2021, 12:59 PM
Thank you Stealthee
:frown:
:frown:
Automotive Network, Inc., Copyright ©2025