cold start engine knock? - F150online Forums



cold start engine knock?

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  #1  
Old 11-20-2009, 12:30 AM
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Unhappy cold start engine knock?

My truck knocks while it warms up, but truck sounds good once fully warmed up. I have a 97 f150 4.2 with 97,300 miles. I replaced the front timing cover gasket, headgaskets, and intake gaskets about 5 months ago, so i could avoid the whole hydro-lock issue. I am using motocraft 5w20 and fl-400s filter. any ideas? Thanks
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Old 11-20-2009, 12:34 AM
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One thing i did notice is that when i done my work to my engine, i went ahead and pulled the engine from truck and when we put it back in i drove it for about a week before i saw that the knock sensor was unplugged. It never set off the engine light. Could a bad knock sensor produce these symptoms?
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Old 11-20-2009, 02:41 AM
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my 02 has made a sorta knocking sound...if you really start trying to listen for it it tricks you into making it louder.. its made this noise since day 1...and it has over 120 k.. what im trying to get to is it really loud or are you just listening to it more.. i dont know much about these knock sensors on fords...but i raced a few of the 88-95 z71s in a stock dirt drag a few years ago and never hooked the knock sensors up on them..
hope i give you a few ideas im sure someone will get on here with more knowalge then me
best of luck
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  #4  
Old 11-20-2009, 04:48 PM
glc
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That sounds like piston slap.
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Old 11-20-2009, 05:37 PM
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Is this a normal trait on the early 4.2's? i know that the injecters are a little noisy on these engines to though.
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  #6  
Old 11-20-2009, 05:58 PM
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My 99 has a little injector noise but no knock with 114,000 on it. 5-20 is a little light. My 99 owners manual recomends 5-30 or 10-30 as an alternative. Don't know if that has anything to do with it.
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  #7  
Old 11-20-2009, 07:34 PM
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I've got a pesky engine tick... brought it to the dealer about 3 times and all they told me was that it is injector ticking, which is normal.

It just sounds loud to be injector ticking.

The funny thing is it only occurs from 900 rpms and slowly fades when I get up to 1800 rpms. It makes more noise when I'm in gear when I have my foot off the pedal.

I've listened and listened and I can't figure out where the heck it is coming from.
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Old 11-21-2009, 12:07 AM
glc
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Quote:
5-20 is a little light.
Nope - Ford brought out a TSB in the early 2000's recommending 5W20 in all engines going back to 97, and earlier in some cases. This supersedes the owner's manual.
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Old 11-21-2009, 01:02 AM
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Quote:
Originally Posted by manualf150 View Post
i've got a pesky engine tick... Brought it to the dealer about 3 times and all they told me was that it is injector ticking, which is normal.

It just sounds loud to be injector ticking.

The funny thing is it only occurs from 900 rpms and slowly fades when i get up to 1800 rpms. It makes more noise when i'm in gear when i have my foot off the pedal.

I've listened and listened and i can't figure out where the heck it is coming from.
do you have a block heater?
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  #10  
Old 11-21-2009, 10:05 AM
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No I dont have a block heater. I wish I did though...

I really wish I could figure out where it is coming from.
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  #11  
Old 11-21-2009, 01:02 PM
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There easy as heck to install and there not that expensive you might want to check it out the only other thing youll have to do is replace all the radiator fluid. In a way its like getting two birds with one stone.
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  #12  
Old 11-21-2009, 01:38 PM
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Sounds like piston slap to me. My 01 had that issue. I put in some Auto-RX to cleanout the carbon and that quieted it down. Eventually the carbon build up returned, and so did the knock, and I had to do another treatment.
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  #13  
Old 11-21-2009, 03:27 PM
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I should make a video of it at some point...
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  #14  
Old 11-21-2009, 04:57 PM
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I had the injector tick too. It's a good way to verify if your injector cleaner is doing anything. Schaeffer's neutra quieted my ticking.
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