Started my car yesterday and as I was accelerating, it made a very loud noise. It sounds like normal engine acceleration noise, only ten times louder. It was present whenever I accelerated, but not when I was coasting or idling, and not when the car was in neutral. (It’s a stick shift.) During acceleration, there was a little hesitation and a little jerkiness, but not horrible. The problem came on suddenly - no problems with the car before yesterday. Can anybody offer advice?
We need to know if this is an ENGINE NOISE…or a DRIVING/MOVING noise. In neutral rev your engine…do you hear anything Awry? Is your engine making any “bad” noises…If not…GREAT… Next drive the car as normal…got a noise thats not normal? OK… Now drive it normally till 3rd gear…then push in the clutch and put it in neutral and coast…noise go away? We gots questions and you gots answers…
Saying you have a “noise” is NOT going to help anyone. Could be as simple as a hole in your muffler…which would be present in the driveway at idle (maybe not noticeable at idle tho) then if you rev the engine you may hear this Hole in your muffler…
Or it could be something in the transmission…or with any moving part while the car is in motion…
WE NEED MUCH MORE INFO TO EVEN BEGIN TO HELP YOU
I think the answers to your questions were in my original post: no noise when idling,coasting, or neutral.
It’s a stick shift…how many miles on your clutch? When is the last time you checked the fluid in your clutch master cylinder?
Does it sound like the engine is revving much faster than it should when you accelerate? If the answer is yes, you problem is with probably with your clutch.
Did you REV the engine in neutral at a stop? Or does it only make the noise while accelerating and under load… Could be as simple as a loose heat shield on an exhaust component…(most commonly the Cat) that rattles loudly while under load and accelerating…this is actually very common. The engine and exhaust vibrates much more while under load and accel…so I would start by looking at your heat shields… grab a 2x4 or other suitable item to reach under and tap around your heat shields to see if any came loose. I would start there.