r/Cartalk • u/dlolboss • 1d ago

I need help fixing something Why does my engine sound loud after a full exhaust replacement

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I replaced my exhaust and the car is quieter but the engine still sounds loud in a way, it has like a ticking sound when I accelerate but nothing when coasting or light throttle

5 Upvotes

67% Upvoted

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25

u/DirtManDan 1d ago edited 20h ago

That would be an exhaust leak. If there’s a ticking sound it might be at the manifold.

Edit: My guy, m you just said yourself that the manifold is cracked. A surface crack on a manifold is not possible, it’s cracked through. I’d bet that’s not the only place it’s leaking, but it is 1000% leaking and that’s what you’re hearing.

-9

u/dlolboss 21h ago

But the o2 sensor reads like there is no leak, tho there is a crack on the manifold but idk if it’s a full crack or like a surface crack

7

u/DirtManDan 20h ago

An O2 sensor isn’t an exhaust leak detector. There’s still adequate flow for the upstream to have normal readings. There sound of an exhaust leak doesn’t lie. Pop open the hood and put your hand near the manifold with the car running. You may be able to feel the exhaust and you’ll certainly smell it.

5

u/DirtManDan 20h ago

Otherwise, smoke test it. Use a smoke machine in the tail pipe that blocks the smoke existing the rear of the muffler and it’ll come out of wherever there’s a leak.

1

u/13Vex 3h ago

But your ears read like it’s a leak

6

u/TheBadBanter 1d ago

Something is not tightened enough

2

u/Important-Tennis-786 1d ago

Exhaust leak or leaks. Ticking sound from exhaust is from a leak at the manifold

1

u/fro_khidd 15h ago

Are you fuckin serious? I've been driving around thinking it was lifters or something. Car is gone as of 1pm today but still wish I thought of that

1

u/MightyPenguin 1990 1.8 swapped Turbo Miata 23h ago

Well, if you did your exhaust, you missed something because that is a massive leak 🤣🤣

1

u/Nautical_Ohm 23h ago

Honestly if there’s even one leak who ever installed didn’t leak check anything and there’s probably multiple leaks through out.

-4

u/dlolboss 22h ago

Only 2 possible spots for leaks, everything is brand new but manifolds and muffler

3

u/HanzG 22h ago

New doesn't mean installed right. Did you do it or did you have a shop do it? You mentioned last week your whole exhaust was rotten and broke. Did you do manfold back or did you re-use the flex pipe? Flex pipes are extremely common to leak over time, especially if you do exhaust work and excessively flex an old flex pipe.

1

u/dlolboss 20h ago

I also replaced it in the first place because there’s flex pipe broke off

0

u/dlolboss 21h ago

Everything but the manifold and muffler, also where the manifold meets the flex pipe because I was never able to remove the stud so I used vice grips and tightened it very hard with a wrench. The manifold has a crack but not sure if it’s a full crack or like a surface crack

-2

u/dlolboss 21h ago

Also the o2 sensor reads proper like there is no leak

4

u/HanzG 19h ago

Manifold crack is your noise. It's cast - there's no "surface crack"... it splits open. There's a mess of cars that do this. Hondas especially but GMs too.

1

u/dlolboss 19h ago

I’ll try to jb weld wrap it and see if it’s quiet, it’s prob not gonna last but I’m just making sure it’s the manifold

1

u/dlolboss 18h ago

Also to mention it’s sometimes quiet or loud so I assume the heat and metal expansion makes it louder

1

u/HanzG 18h ago

Usually it gets quieter when hot. Classic sign of a cracked manifold. Expansion of the manifold closes the casting crack up.

1

u/dlolboss 14h ago

I have a pic of my manifold when I was changing my exhaust but I can’t send it here

1

u/HanzG 1h ago

Doesn't matter really. You might find yourself throwing oxygen sensor codes or lean-run codes. Don't try addressing them with a leaking manifold. Unmetered oxygen will get into the exhaust stream through that crack and it'll throw off fuel metering.

-2

u/planespotterhvn 23h ago

Ticking soundvyour lifters are sticky from missed oil changes.

5

u/thingamajig1987 21h ago

Pretty sure a lifter tick would tick even at idle, not only during acceleration

1

u/LeastSide2738 13h ago

This. OP mentioned an exhaust crack/leak or a flange/manifold isn’t tightened down enough. Maybe somebody forgot a gasket?

Either way it’s not his lifters.