Knocking Noise when I Floor it..please help.

[solaris=amazing]

Ok, my thunderbird is a 95 lx 4.6liter, with alittle over 122 thousand miles. When i have to floor it sometimes, or am merging on to the highway, at like 20mph, then give it alot of gas to get on, i'll hear a very slight knocking noise under the hood. It is very slight, i'd rather don't even wanna call it "knocking", cause it's not that bad. Only in these situations, it will happen. Like if i'm at a light, and wanna put the pedal to the floor, it will accelerate fine, but once it reaches around 40-50mph, and is still climbing, i'll sometimes hear this light knocking. The car accelerates fine besides that, no skipping, shuddering(no tranny problems at all) and the engine seems fine to. Hot or cold weather this happens.

PS.. Once again, this is not even that audible, i think i'm making a mountain out of a mole hile. But if you have any insight, please reply. The noise is definetly coming from the engine though, under the hood. Not the rear end or tranny.

[thunderbird muscle]

Does it do it when you crank it up?

[solaris=amazing]

No everything is fine when i start it, even if i rev it up past 5000rpm's-sounds real good actually. Maybe i'm hearing the belt on the engine moving faster/cause the increase in gas i give it?? Belt is fine also, no rotting/shredding at all. At a stop, ok, lets say i want to put the pedal to the floor, if i do it slowly(pressing pedal to floor)i can go all the way past 70mph, and this noise will not be present. Only when i really get on the gas, this noise will be heard.-Like flooring it

[thunderbird muscle]

Could it be the timming chain tenchenor(can't spell) Mine does a light tapping when first cranked and this is the problem. Hope to be of some help.

[RavenProjecT]

check your plugs and wires for one, and two: have you made any recent changes in gas grade (higher or lower octane than before)?

[H1ghWayMan]

Originally Posted by solaris=amazing

Ok, my thunderbird is a 95 lx 4.6liter, with alittle over 122 thousand miles. When i have to floor it sometimes, or am merging on to the highway, at like 20mph, then give it alot of gas to get on, i'll hear a very slight knocking noise under the hood. It is very slight, i'd rather don't even wanna call it "knocking", cause it's not that bad. Only in these situations, it will happen. Like if i'm at a light, and wanna put the pedal to the floor, it will accelerate fine, but once it reaches around 40-50mph, and is still climbing, i'll sometimes hear this light knocking. The car accelerates fine besides that, no skipping, shuddering(no tranny problems at all) and the engine seems fine to. Hot or cold weather this happens.

PS.. Once again, this is not even that audible, i think i'm making a mountain out of a mole hile. But if you have any insight, please reply. The noise is definetly coming from the engine though, under the hood. Not the rear end or tranny.

My 88 3.8 V6 does a similar thing but I know I have one new and one old Motor mount and it started whe the new one was fitted. They're quick and east to check that the bolts are tight. When I get a non-rainy weekend I have the other one to fit.

[solaris=amazing]

No, no change in the gas i use. Took it to a mechanic, and we found out that there was NO OIL IN THE ENGINE...... LOL, just kidding. I honestly don't know what it is but probably get it checked and let yall know. Thanks alot.

[solaris=amazing]

Today, on the highway, i listened for any odd noises at speeds between like 50 and 80, nothing. But if i'm cruising at those speeds, say 70mph, then floor it, it will accelerate fine, but i'll hear that noise under the hood. Almost sounds like a noise that some kind of chain would make, not so much of a knocking. As far as motor mounts and stuff-thats not the problem. What could this be??

[FordMan77]

sounds like spark knock, or "ping" as some know it. May be time for a good tune up, change the fuel filter, replace air filter, and maybe run some Seafoam through it. Prob. carbon building up in it.

[solaris=amazing]

Actually, i think i found the problem, the culprit so to speak. I have the 4.6 v8, now, as far as the pulley wheels and such, i don't know what the small one is called so here goes. The smallest wheel that is in chain with the other bigger wheel's(pulleys) seems to have alittle play in it. Nothing major, but if i hold the wheel, and move it, i has alittle movement. The noise it makes when i move it is pretty much the noise i'm describing. Only at a faster rate, making the tick tick tick tick noise when the engine is PUSHED. Funny, the wheel itself is fully tightened, but still has some play.

[solaris=amazing]

Forgot to tell you the location. The small wheel i'm talking about is at the top, right to the left of the biggest pulley wheel. It's about 2-2.5inches in diameter. Is this the belt tensioner???