Hey guys,
Quirk #1 that I'd like your opinions on is a strange intermittent noise. It only happens on a cold start, after sitting for a couple days. It sounds like a low, sheet metal-esk shudder, like part of the exhaust system or heat shielding. The thing is, it ONLY happens after a couple days of sitting and ONLY for a fraction of a second between engine cranking and idle. The noise is gone before you can let go of the key. Sitting in the driver's seat it seems like it's in the engine bay, not under the truck.
At first, I was thinking possible lifters leaking down, but there is no lifter tick, ever, and if it was leaky lifters, wouldn't it present itself more often and for a longer duration. it's also more of a sheet metal rattle than metal on metal pinging/knocking that lifter tick usually presents as. Now I'm leaning towards heat shielding, but again, why would it be sporadic and only on first start of the day after sitting for several days and not all the time?
She's been sitting now for a few days and I'll be driving her tomorrow. I'll try to come up with a better noise analogy, possibly have someone else turn the key while I poke my nose under the hood, until then, all opinions welcomed.
Quirk #1 that I'd like your opinions on is a strange intermittent noise. It only happens on a cold start, after sitting for a couple days. It sounds like a low, sheet metal-esk shudder, like part of the exhaust system or heat shielding. The thing is, it ONLY happens after a couple days of sitting and ONLY for a fraction of a second between engine cranking and idle. The noise is gone before you can let go of the key. Sitting in the driver's seat it seems like it's in the engine bay, not under the truck.
At first, I was thinking possible lifters leaking down, but there is no lifter tick, ever, and if it was leaky lifters, wouldn't it present itself more often and for a longer duration. it's also more of a sheet metal rattle than metal on metal pinging/knocking that lifter tick usually presents as. Now I'm leaning towards heat shielding, but again, why would it be sporadic and only on first start of the day after sitting for several days and not all the time?
She's been sitting now for a few days and I'll be driving her tomorrow. I'll try to come up with a better noise analogy, possibly have someone else turn the key while I poke my nose under the hood, until then, all opinions welcomed.