Billman250

Did you lose an oil cap under the hood? Commonly falls behind the engine and will not eixt, squeaks and rattles.

snayl

Nope, oil cap is still on there.

Car Analogy

Buthow do you know if a po llst the cap, or even the shop that recently worked on it? They would just put a new one on, and old one could be stuck down there.

snayl

?

Slowcrash_101

caps often get lost and stuck in the transmission tunnel. It's not uncommon to replace the cap while the lost one rattles for ages until you decide to pull the transmission.

Car Analogy

Maybe we need to explain more. A common thing that happens with these cars is someone removes the oil cap to add oil or whatever, lays cap on valve cover or similar, then starts the engine (like maybe they expect to have to add more oil, but they want to start engine to fully fill oil filter , etc), motivating cap to slide off. It often slides back, and falls on top of trans, where it gets trapped. It can stay there for years, rattling around and making odd noises as you drive.

So when whoever did this can't find the cap, maybe they think it rolled away under something in garage or shop, they just replace with a new one. Often this is a shop, that never mentions the incident. An owner might be more diligent looking for ood cap. A shop ots cheaper to buy a new cap than waste time looking for old one.

To find such a rogue cap is not so easy. It gets itself way up under there. There is a special technique Billman has described before. You can search for it. Basically it involves jacking car up safely on jack stands, then reaching waaaay up on top of trans in just the right spot, then probing around with your hands searching for it. Its a bit of a contortionist move.

Mr.Matchbox

I am still opting for a exhaust leak. However, searching for a lost oil filler cap or a exhaust leak is a piece of cake for a expirenced mechanic with the car on a lift. Should be done in 15 Minutes.
Cheap and worth a try!