I thought that it’d be a good idea to save myself $1200 and replace my oil cooler myself. I got it apart and put the new cooler in and decided that this was a job for an actual mechanic. Local shop picked up my truck and the extra parts and I had them finish the install. They said I had everything taken apart well other than I pinched the injector harness in the intake manifold, so I had them replace the harness. When they got it back together they told me that the truck ran like garbage and it did. They told me that I might have sucked an o ring into the head when I did the blue spring or a bolt into the cylinder. The 3 cylinders that arnt firing only had 200psi of compression, I believe that it’s numbers 3,5 and 7. After the compression test the shop told me to give up on the truck and sell it for whatever I can get for it because they said that it needs a motor. I refuse to believe that I could’ve messed up the motor doing an oil cooler but I don’t know what else to do. Can’t afford to have someone tear it apart to find out that it needs a motor. At this point I’m just gonna drive a beater for a year and get a loan to buy a new longblock, turbo, injectors, meth kit and other goodies. Has anyone else had a similar problem after replacing the oil cooler or blue spring? Seems like it could be a valve-train issue or something else small but the shop I have it at insists that I need to sell it and it’s not worth fixing.