95 Mustang Engine tapping noise

[sonoflarry]

95 Mustang 3.8 V6. New purchase. 80,000 miles. I recently noticed an engine tapping noise but only under certain circumstances. No noise when engine is in idle or general driving conditions. But I hear the metal tapping noise when in park and rev up the engine or if I accelerate fast after a stop sign and get the engine up to 2500 to 3000 rpm before it shifts. No noise below 2500 rpm. I decided to flush the engine and change the oil. When I turned the car on after this, the engine made that tapping noise but only for two seconds until the new oil had a chance to recirculate. What's the problem, bearing? rods? rockers? valves? I don't think its injectors or converter noise. What is the best way to isolate where the noise is coming from?

Thanks

[Future303]

Could you be hearing Engine Ping? Try disconnecting the battery so your computer is reset.

Other than that, maybe check the timing with a timing light, and put a higher octane fuel to test it.

[silverstangs]

Originally Posted by sonoflarry

95 Mustang 3.8 V6. New purchase. 80,000 miles. I recently noticed an engine tapping noise but only under certain circumstances. No noise when engine is in idle or general driving conditions. But I hear the metal tapping noise when in park and rev up the engine or if I accelerate fast after a stop sign and get the engine up to 2500 to 3000 rpm before it shifts. No noise below 2500 rpm. I decided to flush the engine and change the oil. When I turned the car on after this, the engine made that tapping noise but only for two seconds until the new oil had a chance to recirculate. What's the problem, bearing? rods? rockers? valves? I don't think its injectors or converter noise. What is the best way to isolate where the noise is coming from?

Thanks

Pull the valve covers off, and wiggle every rocker. I would say one of them might be comming loose. It would also be a good time to check the lash on those rockers. If those check out find, then do a compression test...... start with the passenger side rear cyclinder since that one is most prone to busted head gaskets.

[grapony]

If your heard the noise before the oil pressure got built back up it's a sure sign of rod bearing clearance. Gooseing the engine and letting it come back down is another way to hear the worn bearings also.

[sonoflarry]

Originally Posted by grapony

If your heard the noise before the oil pressure got built back up it's a sure sign of rod bearing clearance. Gooseing the engine and letting it come back down is another way to hear the worn bearings also.

So what is involved in repairing this problem? Cost?

[ModMech]

Another common 3.8L problem is the cam follower keepers breaking (they are plastic) allowing the follower to jump around on the cam, NOT GOOD. Ford switched to the plastic parts in the mid '90s, I'm not sure when exactly.

As suggested, it could also be main or rod bearings, but they sound "heavy", not like ticking.

[sonoflarry]

Originally Posted by ModMech

Another common 3.8L problem is the cam follower keepers breaking (they are plastic) allowing the follower to jump around on the cam, NOT GOOD. Ford switched to the plastic parts in the mid '90s, I'm not sure when exactly.

As suggested, it could also be main or rod bearings, but they sound "heavy", not like ticking.

The strange thing about this metal tapping sound is that you do not hear it when you drive the car around town at normal speeds and accelerations. You only hear when 1. fast acceleration and the rpms hit around 2500 or 2. in park reving the engine, then you hear it at around 1500 rpms. I feel the noise is loudest by the intake manifold on the top of the engine. But others think it is lower engine noise. Could the noise be reverberating up through the manifold from other parts of the engine?