4.6 tapping noise

[kware1]

Hello. I'm trying to eliminate what is making this loud tapping noise on my 4.6 v8 Explorer. It sounds a lot like lifters clanging, but after doing some research I found there are some less expensive possibilities.

One was noisy fuel injectors of faculty purge valve solenoid. Another would be a leaky exhaust manifold.

My only issue is if the injectors or purge valve was defective, would I get a check engine light?

I'm just hoping for something easy for a change. The last few months been paying out at least 300 per month in repairs.

 

[Truth Explorer1]

Timing chain

The timing chain guides are know for wearing out in these motors, and when they do, they make a very similar noise. Had mine go bad at 154,000 miles. You can pull the valve covers off to inspect the timing chains and guides.

 

[kware1]

Hey, thanks,

I actually heard that too, but I dismissed it because I had the timing chain and guides replaced about less than two years ago. I must have put in about 30k since then (long commute). Is possible they went bad again? I took one of the covers off, where I thought the noise was coming from but from what I could see, nothing looked out of order. However all the bolts that hold the lifters in place were loose.

I paid about $1000 for the timing chain, guides, and something else dealing with the oil pump or pan. Don't think the oil pump was replaced. Any idea on how much just replacing the guides might cost?

 

[Truth Explorer1]

Guides

You can buy the timing chain kit for around 200 bucks. It seems very unlikely that if u had them replaced a few yrs ago that they would have gone bad again. Unless the engine has gotten hot on mulitple occasions. Or you never chainge the oil. Wich I also doubt is the case. clogged injectors, tourqe converter bolts, idler pully, are all common causes of similar noises. If u have a long handled screw driver u can use it like a stethascope. Put one end near where u think the noise is coming from, and the other to your ear. It can help isolate the noise. Good luck brotha!

 

[icepickjazz]

Did you ever figure this out? My 4.6 makes similar noise coming from passenger side compartment. Especially noticeable during acceleration.

 

[torment1979]

I've noticed every 4.6L V8 I've heard has a general tapping sound while running. But if there is a sound coming more so from one side. I would be think rocker slack, maybe your rockers have to be adjusted. Or worse case a bent connecting rod, which you would hear at high rpms.

 

[bcbow1971]

I am having the same noise from my right side motor as well at 122,000. I changed the plugs hoping it was that with no change. I will pull the valve cover off and check the timimg changes.

 

[kware1]

still making noise

I was just reading this thread again and noticed a post that stated if the engine had overheated several times or if the oil had not been changed, it could cause premature wearing of the chain guides.
I've always changed the oil in time, but I did have an issue with the intake manifold which cause the engine to overheat. I can remember at least 2 or 3 occasions where the engine overheated enough to shut down.
I'm at 198k now and the noise is still there. No one has been able to pin down what the problem is although I never had any type of pressure tests done or anything.
Recently I noticed oil in my coolant reservoir. Thinking the engine is on borrowed time.