I have a 2008 Mitsubishi Lancer GTS 2.0 with 160k miles and every time I cold start this car it starts to run a little rough and make a rpm drop then makes some noise and runs good after 30 seconds. This only happens if it’s been like more then 8 hours of the car not being touched or a day. I’m thinking this is an issue with timing especially somewhere in the VVT portion. I hooked up a vacuum gauge and reads normal until the engine starts to run rough and vacuum drops close to 0 and comes backs to normal after those 30 seconds. The timing chain has been done about 1 thousand miles ago and was double checked to make sure the timing was good also the VVT solenoid has been replaced on the intake side since it was Brocken. There is no codes and after these 30 seconds the car drives and acts like a normal car. The car has been doing this ever since I had it. Can someone please lead me to the right direction. I even put a link here on YouTube to make it easier to understand what’s going on: Cold start
Cold start with vacuum gauge: https://youtu.be/AiJCo4rVJqY
Sounds like a cold start vacuum leak that seals up quickly. I would take a serious look at that 14 year old EGR valve and replace the pcv valve.
Ok I’ll take a look at the egr valve tomorrow and while I’m at it I’ll probably give it a clean and keep you guys updated
Ok so I took the egr valve out and tested it to make sure it’s good and the resistance readings are within spec, I also cleaned it out and the ports on the engine since they were gummed up and the valve also moves freely. The pcv valve is also good working condition. The car hasn’t been started since yesterday and it has the same noise as if there were lifters in the engine making a ticking noise then go away. But this car does not have any lifters. This time the car did not do that rpm drop and actually did a bit better on cold start.