Loud knocking sound in motor

[SN_ASAP]

I have the v8 5.0 edition and there has always been a small tick when I accelerated and I was told to not worry about it. Then I overheated recently and it just grew to a loud know and after it cooled down I filled it with water and started it up and the noise is still there and only knocking when the car is out of park.

 

[J_C]

Although it's going to be harder to see anything since you report it isn't doing it in park, you might want to pop the hood and see if you can detect any excessive wobble in anything, the belt tensioner (or just loose belt), water pump, AC, alternator, steering pump, though if water or steering are that bad they're probably leaking fast too... but you did report overheating and needing to add water. Where is your water loss coming from? Edit: Never mind, I see in another topic you had a radiator leak.

I wonder if recording the sound and posting it on youtube would help someone identify it.

I assume you're using the right spark plug heat range, don't have dodgy poor fuel in it, aren't using detergent free oil, no vacuum leaks (no lean or other engine trouble codes set?) nor anything else that could contribute to predetonation knock, but if that is what is happening, it's no surprise it would happen worse with an overheating engine.

Just for the heck of it you might see if topping off the tank with premium fuel helps. It's about the cheapest/easiest thing to do to narrow down if it's predetonation.

I'm not sure if your generation of V8 has a knock sensor but I was led to believe it didn't. There could instead be more serious problems like internal wear. How many miles on it? How long was it overheating?

 

[SN_ASAP]

My oil is fine I use good gas. I just hit 174500ish the previous owner explained that the radiator leaked but he added bars leak and it stopped and presently started up again. I'm worried its a warped head or I might need to rebuild. I can't really explain the sound any better till tomorrow I'm having the radiator fixed rn. I was told there was an exhaust leak and tracked to around the manifold.

 

[J_C]

Without oil in the coolant, coolant in the oil, or one or the other being consumed (burnt or leaking, once your radiator leak issue is resolved), I doubt it's a warped head (or head gasket). It wouldn't be an exhaust leak either. Regardless you could do a compression test but it seems like you'd have a misfire trouble code set, have rough running, loss of power not knock.

At that mileage I suppose internal engine damage is a possibility consider the prior owner was a little lax in maintenance to just add bars leak instead of replacing the radiator or at least a bunch of epoxy to patch it if money was tight and it was a plastic end that cracked, though I suppose it could have been one of those straw that broke the camel's back situations, that the radiator leak was what precipitated selling it instead of putting more work into it.

 

[SN_ASAP]

OK radiator is fixxed now. I tracked the knock to the passenger side of the motor near the exhaust manifold, I got my check light tested and I need to replace my camshaft position sensor, could that be the problem?

 

[J_C]

^ I would have thought that would keep it from starting at all, but honestly I don't know.

 

[deadernie]

Without being able to hear it it's going to be hard to tell. But I'm betting on it being a exhaust manifold leak. Does it get louder or quieter when it warms up? My Explorer has a passenger side (and probably driver's side though not as bad) exhaust manifold leak. It's pretty loud when I first start it up and gets a good bit quieter as it warms up. It's also more of a ticking sound than a knocking sound.

Old motor mounts could help explain the sound starting when you put it in gear.