tl;dr; If I have an exhaust leak that is sufficiently small such that upon the engine heating up the leak was reduced or removed to a satisfactory level to avoid seeing a Check Engine Light (CEL); how long would that be; is there a buffer for the light to appear? Could I buy a code reader and see the problem before it was resolved?
I have a 2016 Ram 1500 5.7L that started making a louder ticking noise on start as of late. At cold start, it will tick loud enough to hear inside the cabin with all doors and windows closed. After it warms up, it [mostly] goes away though I'm hearing it under the right conditions (and in my sleep); I get no CEL. My understanding is emission problems result in a CEL.
Prior to the sound, two events happened about the same time:
- I installed a K&N lifetime air filter which, at first, made the truck very responsive.
- I came down hard on a large bump on a trail at a spot on the truck where the exhaust could've been hit.
While looking into the tick, I've come across two possibilities aside from the fact Hemis tick:
- It's recommended to use 89 and I haven't been. Add that to the additional air I'm getting from the K&N filter and perhaps I'm getting some pre-combustion or something thereby causing the tick.
- I've got an exhaust leak. But after a thorough inspection I can't see anything and the entire system is very tight. I do however seem to smell exhaust fumes on the right side of the engine while ticking.
My thought is that I may have a small leak at the gasket either due to a gasket failure or perhaps I ever so slightly warped the manifold upon impact from the second event above. If that's the case, then I can spend $30 on a code reader and know for sure or spend $180 for the same information at a service center. I would prefer the former if possible.