knocking on startup

[dcarr]

so when i start my truck it makes a knocking sound for about 3-4 seconds. its an 07 5.4. oil level is fine. its done it for a while and hasnt gotten worse. once in a while it is a little longer. its goes away as soon as the oil pres comes up. im wondering if this is common and is there a simle fix or do i need big dollars.

 

[GAINMOB]

might want to get the rods looked at

 

[dcarr]

i was thinking that at first but it only does it on initial startup before the pressure builds. it sounds more top end too.

 

[cboling67]

sounds like the main bearings that connect the rod to the crank are worn. My engine does something similiar except that I have to try and start it atleast twice before it builds enough oil pressure for the sending unit to allow the motor to start. I am considering pulling my motor and replacing the bottom end before it gets any worse.

 

[alaskanexpy]

make sure your running an oil filter with a anti - drain back valve in it. also make sure your running the correct oil weight.

i had this w/mine and it was due to running thinner oil then i should have. after going back to the correct weight i have not had an issue.

but the cam phasers on the newer 3V 5.4's have been none to cause the same type of noise.

how many miles do you have? how often do you change oil?

 

[dcarr]

i did an oil change with a k&n filter to make sure i had an antipass back and i used the motorcraft 5w20 synthetic. same deal its an 07 with 106k. i changre the oil between 5 and 6k usually closer to the 5 but always the rare 6k. i usually put in a quart of lucas but skipped it this time trying to go with the spec oil. its just annoying/embarassing to have a nice truck and when i start it having it knock like that. it happens when i first start it till the pressure comes up(like 2-5 sec) and makes normal pres. it does sound like the deep knock of a spun bearing but its only for that first couple seconds.

 

[GAINMOB]

get it looked at asap...the longer you wait the higher chances you have in increasing damage or worst

 

[toms89]

i did an oil change with a k&n filter to make sure i had an antipass back and i used the motorcraft 5w20 synthetic. same deal its an 07 with 106k. i changre the oil between 5 and 6k usually closer to the 5 but always the rare 6k. i usually put in a quart of lucas but skipped it this time trying to go with the spec oil. its just annoying/embarassing to have a nice truck and when i start it having it knock like that. it happens when i first start it till the pressure comes up(like 2-5 sec) and makes normal pres. it does sound like the deep knock of a spun bearing but its only for that first couple seconds.

I would put a motorcraft filter on it to make sure its not the oil filter. You make it sound like its taking quiet some time to build pressure which could very well be the oil draining out of the passages. Oil pressure should build almost immediately if the passages are full.

It may be a rod bearing or cam phasers as mentioned but 1st eliminate the possiblility of the oil filter...use OEM.

I have used "high performance" filters in the past that created the infamous knock due to lack of oil on start up. I changed them immediately.

 

[dcarr]

how hard is it to change cam phasers?

 

[rca510]

i have a 05 that i also get a ticking sound like a lifter or rod know on mine. i have about 148k on it. it has plenty of power but just the ticking sound bugs me i have read a few things that maybe the phaser are clicking. a repair shop said its lifter. has anyone fixed the issue with just cam phaser or was there more to the fix?

 

[mazdaparts]

Could be timing chain slap. I believe 100k is the recommended interval. Could be lots of things. Keep us posted.

 

[ydopen]

My 5.4 had 188k on it whe I got it and has 220k on it now 4 years later. It has had the cold start knock in it since i got it and is worse in the winter. I have spoke to my mechanic/buddy and he said its a 5.4 thing.

I just let it warm up for a minuite before i take off, and i change the oil regularly with a good filter with a check valve in it.

It worried me at first but now im use to it, It will still lay down a burnout lol

 

[01yellerCobra]

I didn't know these trucks had the phasers. Good to know.

If it goes away after a couple seconds it's probably one of the timing chain tensioners. I had that issue in my Cobra. Replaced the primary tensioners and it went away. I do need to do the secondaries at some point for peace of mind. If you do find out it's the tensioners make sure to get the ones with steel bodies. They have a ratcheting mechanism that keeps tension until oil pressure builds up. The plastic bodied version doesn't have that mechanism