Top End Engine Noise

[James McCluskey]

So, I'm trying to get an idea of what to expect when I open this thing up.

There is a "clatter" noise on acceleration, under a load. It seems to be coming from the front of the left bank (drivers side). It's not there at idle, and goes away once the load of acceleration is reduced.

It's got me stumped, I've never heard a noise like this, and I'm a former Ford Service Manager with 25 years of experience. (I'm a nurse now).

Any input would be appreciated, thanks.

 

[swshawaii]

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[imp]

So, I'm trying to get an idea of what to expect when I open this thing up.

There is a "clatter" noise on acceleration, under a load. It seems to be coming from the front of the left bank (drivers side). It's not there at idle, and goes away once the load of acceleration is reduced.

It's got me stumped, I've never heard a noise like this, and I'm a former Ford Service Manager with 25 years of experience. (I'm a nurse now).

Any input would be appreciated, thanks.

@James McCluskey

Acceleration of engine speed car standing, or acceleration of car itself? Look first carefully for some loose part rattling underhood when accelerating engine up; save possibly tearing into it for nothing. Nothing found, consider chain guide theory: under load (acceleration) chain tightens all up (much as possible) lessening any racket due to wear, unless guide(s) cracked, broken, missing, tensioner jammed, etc.

German thinking behind hydraulic tensioners is good and bad: No tension until oil pressure up, but control of tension possible by oil pressure. Either way, gummed-up tensioners are bad. 4.6 method superior, IMO. For awhile, the rage was to add an oil pump, run electrically, on several seconds before engine crank, tension chain before start. Madness. imp

 

[Number4]

Also, based on the symptom, not location, it could be a bad cat converter.

Because this is the 4.0, I’d strongly, strongly suggest you immediately stop driving it. In fact, if a shop is going to do the repair, tow it there.

This engine is know to let the timing loose with no sign. Which means you need a new engine. And your engine is giving you a sign.

 

[TechGuru]

So, I'm trying to get an idea of what to expect when I open this thing up.

There is a "clatter" noise on acceleration, under a load. It seems to be coming from the front of the left bank (drivers side). It's not there at idle, and goes away once the load of acceleration is reduced.

It's got me stumped, I've never heard a noise like this, and I'm a former Ford Service Manager with 25 years of experience. (I'm a nurse now).

Any input would be appreciated, thanks.

I remember something like that back in the days on vehicles being caused by crappy sub par octane gas. Put some TopTier gas in it and see if it goes away. I'd run a tank or two of plus or prem. Carbon builds up when you use crappy gas and that carbon takes up space thus increasing the the compression ratio causing detonation on regular gas. If yours is a flex fuel run two tanks of E85 though it to really clean it out.