To my extreme disappointment my truck which I bought a year and a half ago (and 15000km) needs injectors and has low compression in 1 cylinder. I have been having the wait to start light issue ever since I got my smarty and finally got around to having it diagnosed. The shop I took it to did some testing and determined my return rates were high. They also did a relative compression test which showed one cylinder about 20% lower than the others. We followed it up with a manual compression test which showed cylinder 1 at 300psi. I was told min is 360psi. They also bench tested the injector and confirmed over fueling. This engine was rebuilt just before I bought it but the injectors were not changed. So Im pretty unhappy. So here is the dilemma. I don't have the time or facilities to do a rebuild myself and for what it will cost I don't think I am going to keep the truck. I am thinking I will just have to sell at a loss and get something else. I was also thinking though that if I change the injectors and keep running the engine it might last anyway? That's my question. Is the compression likely to just continue to get worse quickly or might it hold? On the other hand I don't want to throw injectors in and end up selling it when the engine fails in a short period of time. Thanks for the input and opinions.

 

You never know what may happen. You may drive it for several more miles. Sounds like you have a ring that didn't seat. You could pull the engine down in frame, hone the cylinder and re-ring it if the piston is still good. What could of happened is the ring never seated, hence the loss of compression. I would replace all 6 injectors and see what happens. If you aren't burning any oil, go for it. Most of the time a broken ring will show it's ugly head with the engine using oil.

If all goes well for several miles after the injector change I would take the truck for a good drive with a heavy load. That should seat it.

 

Thanks for the reply. I pulled the head last night, as I figured it was an inexpensive way to see what was going on. The cylinder in question looked great no signs of any damage. That piston didn't look any different than the others. I'm kind of stumped as to why the compression would be lower, unless the rings didn't seat properly like you said. I talked to the guy who did the rebuild 15-20k km ago and he said that he has seen them take longer than that to seat. He has built quite a few of these. I think I'm going to slap her back together and put some new injectors in and drive it and monitor things. I haven't been using any oil either.