Triton 5.4 Engine Problem - F150online Forums

Go Back  F150online Forums > Powertrain & Mechanical > V8 Engines
Triton 5.4 Engine Problem > Triton 5.4 Engine Problem

Triton 5.4 Engine Problem

Reply

 
 
  #1  
Old 08-22-2011, 08:29 PM
Junior Member
Thread Starter
Join Date: Aug 2011
Posts: 2
Triton 5.4 Engine Problem

I recently purchased a 99 f150 with the 5.4 in it. It had 85,000 miles on it.

When i bought it there was an exhaust leak in the intermediate pipe which made the exhaust pretty loud. however after i fixed the leak i noticed an issue with my engine.

At around 1500 rpm or higher i get an engine knock. it honestly sounds like a hammer on metal that follows the rpms perfectly. It doesn't happen at low rpms at all. It is a very consistent noise. Its the same sound that is the same level of noise and the same patter to the sound (identical to the rpms) everytime To me it sounds like a woodpecker banging away, and under 30 mph can be easily heard with the windows down. It can be heard in gear, in neutral, in park it doesn't matter. It doesn't make any sound cold. repeat until the engine gets warmed up you can rev it up all you want but it makes no sound at all when cold, sounds like a nice beautifully running engine. only when it gets to normal temperature does the noise start.

I gave it brand new motorcraft plugs as a tune up and upon a couple of people's insistence an oil change. I drained the old oil which was really dark but no obvious shavings or anything and added 6 quarts of Valvoline conventional 10-40W and one 32oz container or Lucas Heavy Duty Oil Stabilizer. oh and a pureolater pure one filter from advance.

After 50 miles under this new setup i notice no difference in the noise whatsoever. its still there and still the same volume. I have no idea how the previous owner treated the truck.

I am an average mechanic that can handle almost any job, but i really wanna pinpoint the source of the problem and the cause before i waste time and money into it.

She runs fine, no issues with acceleration. every now and then she might idle slightly ruff but no big worries. It gets 13.5 mpg consistently.
 

Last edited by mjdaye; 08-22-2011 at 09:11 PM. Reason: to be more descriptive
Reply With Quote
  #2  
Old 08-22-2011, 08:36 PM
Senior Member
Join Date: May 2004
Location: Longmont, CO
Posts: 577
Check to make sure the plugs are torqued properly, one of them may be loose and ready to launch out of the head. Check to make sure they are torqued to about 28lbs. The noise you describe may be the plug wobbling around in the head
 
Reply With Quote
  #3  
Old 08-22-2011, 10:11 PM
Senior Member
Join Date: Aug 2011
Location: ky.
Posts: 678
I would switch to a 10w30 or a 5w30 , but definetly get that lucas out of there.
 
Reply With Quote
  #4  
Old 08-22-2011, 10:41 PM
Senior Member
Join Date: Jul 2007
Location: Beaverton Or.
Posts: 3,264
5/20 is the proper oil. Make sure it is not an exhaust leak you are still hearing. They were common to leak at the manifold on the passenger side and can sound like a knock. But... they are normally more pronounced when cold so I don't know. Get a mechanics stethoscope and pin point the knock. Could be a timing chain guide, bearing etc...
 
Reply With Quote
  #5  
Old 08-22-2011, 11:35 PM
Senior Member
Join Date: Jun 2007
Location: Utah
Posts: 5,522
x2 on the exhaust leak. I've had simular deals turn to be small leaks. Another trick is to look at the exhaust system in the dark you can usually see the leaks.. Had a header leak in my Mach I once that I was sure the engine wast toast. Metal hammering sound.. BTW Lucus is crap..
 
Reply With Quote
  #6  
Old 08-23-2011, 11:45 AM
glc
glc is offline
Senior Member
Join Date: Dec 2006
Location: Joplin MO
Posts: 34,628
Do NOT put 10W40 and/or Lucas into a Triton!
 
Reply With Quote
 
 
 

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
karavansman
Appearance Products
1
09-03-2015 01:06 AM
concreteclauss
Exhaust & Intake Systems
3
08-17-2015 10:34 PM
karavansman
2004 - 2008 F-150
3
07-20-2015 06:43 AM
Ghemp
V8 Engines
5
07-17-2015 08:29 AM
omegaman1955
V8 Engines
13
07-16-2015 07:58 PM

Thread Tools
Search this Thread
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Sponsors

All times are GMT -4. The time now is 10:34 AM.