Hello,
I started the truck this evening 39 degrees out and the idle seemed to immediately jump a couple of hundred rpm's on initial start up (couldn't duplicate it with future starts). I let it idle for a few moments and then shifted into drive and the rpm's dropped a couple of hundred rpm's below idle and then recovered. While doing this I noticed a very distinctive change in engine clatter. When the engine is cold it is much nosier than when fully warmed up, not just mechanical noises like valve train but clatter from the compression ignition process. The clatter will noticeably change as the engine is warming up (timing?). Anyway, my check engine light is on and I pulled the following codes 0122 and 1690. Any ideas?
I started the truck this evening 39 degrees out and the idle seemed to immediately jump a couple of hundred rpm's on initial start up (couldn't duplicate it with future starts). I let it idle for a few moments and then shifted into drive and the rpm's dropped a couple of hundred rpm's below idle and then recovered. While doing this I noticed a very distinctive change in engine clatter. When the engine is cold it is much nosier than when fully warmed up, not just mechanical noises like valve train but clatter from the compression ignition process. The clatter will noticeably change as the engine is warming up (timing?). Anyway, my check engine light is on and I pulled the following codes 0122 and 1690. Any ideas?