5.4 Cold Engine Knock
Senior User
Joined: Sep 2003
Posts: 223
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From: York, PA
They call them Hydraulic Lash Adjusters, I am looking right know at a TSB in Alldata for a rough running cold idle noisy startup at 10'F. Article #00-26-1 on engines built between 3/1/1996 and 7/31/2000, I don't know if this is the same issue though as 97fireman is having or what you are hearing in your engine, I had another Exp. in the shop the other day with 90 thous. on it, and it had the same noise as mine. Broken Wire
Junior User
Joined: Feb 2005
Posts: 60
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Yes, lash adjusters. Is there a reliable way to determine if a noise is coming from the top or the bottom without disassembly -- perhaps with a stethoscope? I know the noise on mine was coming from the connecting rod because I had the bottom end dismantled -- filing the connecting rod journal and installation of oversized bearing eliminated the noise. I imagine that an empty or defective lash adjuster sounds different from a loose connecting rod bearing, but without repeatedly hearing examples of both side by side, I could not tell which is which just by the sound. However, if I could stick my stethoscope probe in the right places, I think I could determine whether the noise is in the top or bottom of the motor.
Senior User
Joined: Sep 2003
Posts: 223
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From: York, PA
Mine is in the top, it is a definite knock sound, if it is in the bottom, they usually have a hollow sound, also rod bearings are going to be more prevalent on startup all the time and stay around also bearing noise usually stays with the engine reguardless of engine speed or heat, mine goes away, may not hear for 5 months, then it will do it once on startup, stay for 30 seconds and go away. I don't think a stethoscope is going to be much help here, noises are to pronounced and to loud for that tool, the loudness would blow out your eardrum. I think LxMan1 is right on the money for 97fireman. Broken Wire
Junior User
Joined: Feb 2005
Posts: 60
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My connecting rod noise occurred only briefly upon a cold start for 30K or 40K miles. Only in the last stages of failure did the noise occur under certain loading circumstances when warm.
So, do you think 97fireman suffers piston slap or lash adjuster knock? How would he be able to distinguish between these two? I find cold start-up noises particulary difficult to diagnose because they are fleeting and without a remote starter or an assitant to start the motor, one must experience the noise filtered through the firewall.
So, do you think 97fireman suffers piston slap or lash adjuster knock? How would he be able to distinguish between these two? I find cold start-up noises particulary difficult to diagnose because they are fleeting and without a remote starter or an assitant to start the motor, one must experience the noise filtered through the firewall.
Senior User
Joined: Sep 2003
Posts: 223
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From: York, PA
The lash knock will go away when the lifters pump up with oil, the piston slap will go away when the pistons start to heat up and expand in the cylinder bores, piston skirt damage is usually caused by and engine that was extremely overheated, pistons being made of aluminium are more susseptible to expansion than cast iron, so the pistons get tight in an overheated engine, and since the skirts are on the inside and outside of the pistons, they take the power of the scaping, next to siezing in the cylinders, From what 97fireman has pointed out, his problem is also in warm weather cold start-ups, must warm up to get past the knocking noise,( piston skirts are growing in the cylinders from heatup)(there is no TSB for piston problems in Alldata) the TSB for lash adjusters and followers was only cold 10'F. Mine has made this knock even at other temeratures than 10'F, I have had it at 50'F, but it goes away within 30 seconds after a cold startup. like I said before, I may not hear it again for 5 months. Skirts, you will hear almost everytime of cold startup, warm or cold climate. Broken Wire
Junior User
Joined: Feb 2005
Posts: 60
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I can't be sure I've ever heard piston slap, but upon thinking about it, I realize it makes good sense that the noise would project through the side of the block into the wheel well. That's a really good hint.
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New User
Joined: Mar 2005
Posts: 6
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i have a 2003 5.4L with 8000 miles on it and i have what sounds like a knock when it's cold.it quiets down when it heats up to the normal range buts still bothers me.Ford says no problem and it's normal.still bugs me though.just doesn't seem right....GB2F
Junior User
Joined: Feb 2005
Posts: 60
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I know. That bugs me too. If it's normal, why do the vast majority of the 5.4L Tritons not make any noise upon start up. In order for someone to say that the noise is normal, he or she would need to know what is causing it. If it is simply a lash adjuster from which the oil has drained, that is probably nothing to worry about, but I would still like to know why the oil is draining from it. I can't imagine that one piston slapping when the engine is cold is not a symptom of something more serious awry. There must be some heavy duty forensic engineers out there who could find out what is going on.
Senior User
Joined: Feb 2005
Posts: 285
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From: Ft. Worth, TX
I have a 99', 5.4 with 76,000+. I have never heard the noises described in this thread, however I have used AMSOIL synthetic 0W-30 since 22K with AMSOIL filters (remote bypass filtration system). I change the full flow filter at 12,000 or 6 months and both filters at 1 year, sample the oil and based on the results keep on trucking. This rig runs GREAT and have no complaints. When I trade, the bypass system will come off and be installed on the next vehicle. This vehicle had both head gaskets replaced under warranty, which is another Dealer gone wrong story 
. I have a diary if anyone is interested. The service manager and the tech were fired.
PS: I have gotten 19.9 mpg in this vehicle just last year, loaded to the point that there was not room for a passenger in the right front seat.
. I have a diary if anyone is interested. The service manager and the tech were fired. PS: I have gotten 19.9 mpg in this vehicle just last year, loaded to the point that there was not room for a passenger in the right front seat.
Junior User
Joined: Feb 2005
Posts: 60
Likes: 0
I am convinced that the 5.4L is a very well engineered engine. I believe in synthetic oil, and I am convinced that a properly used and maintained 5.4L using synthetic oil will last almost indefinitely (meaning 300K miles). The tear-down and close inspection of the bottom end of my 5.4L at 110K showed NO measurable wear on any of the bearings except the one connecting rod bearing that failed, causing the engine to seize. I have heard that the timing chains must be replaced every 100K miles or so, but mine are showing no signs of wear at 110K. It's too bad that spark plug blowout has been such a widespread problem in an otherwise problem free engine. Also, my 5.4L did not burn a quart of oil between 5K miles changes until after the third plug blowout. I'd like to hear about oil consumption in other high-mile 5.4Ls.
Freshman User
Joined: Jan 2005
Posts: 37
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i have the same problem with my 00 5.4,the knock almost goes away when warmed up,but everone laughs that i just bought it and it knocking,go ford.talked about 25 people out of buying one without saying a word. the big issue for me now is i'm unhappy with and want to sell it ,whos going to buy one thats making noise,,,, no one so there goes the resale value.hope ford wakes up and sees the poeple there screwin