Slight knock when cold
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Tuned
Joined: Oct 2006
Posts: 453
Likes: 12
Slight knock when cold
Noticing a knock when cold when idling. Appears to be coming from the bottm end. Dissappears when I rev it and goes away when its warm.
Thought I'd get some forum feedback before I take it in for a listen.
Update: Payed a little more attention to it this morning. The knock does not happen as soon as it starts. Doesn't start untill about 30 seconds and it doesn't get louder if I rev the engine a little. Can't hear it in the cab either. Taking it in to the stealer tonight and have them start in cold tomorrow. I'll update.
S
Thought I'd get some forum feedback before I take it in for a listen.
Update: Payed a little more attention to it this morning. The knock does not happen as soon as it starts. Doesn't start untill about 30 seconds and it doesn't get louder if I rev the engine a little. Can't hear it in the cab either. Taking it in to the stealer tonight and have them start in cold tomorrow. I'll update.
S
FTE Leadership Emeritus
Joined: Jul 2002
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From: Long Island USA
Could be lots of things. Piston slap, rod knock, main knock, or even a loose timing chain.
I have a slight rattle sometimes lately, only happens with it's warm. Starting to worry me. I might have to take a look at the torque converter bolts and flexplate today...
I have a slight rattle sometimes lately, only happens with it's warm. Starting to worry me. I might have to take a look at the torque converter bolts and flexplate today...
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Tuned
Joined: Oct 2006
Posts: 453
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UPDATE
The dealer had it for a couple days.
Something really difficult for them to nail down as it only stays audible for a couple of minutes and then pretty well disappears.
They do know that it's coming from the left bank and may possibly be a scuffed piston. As long as I've owned it, the engine has never overheated which they say could have been a cause.
They changed the oil to 5w30 and to see if that helps any. Not too optomistic.
Haven't had any conversations as to what it takes to repair it. Too scared.
S
Something really difficult for them to nail down as it only stays audible for a couple of minutes and then pretty well disappears.
They do know that it's coming from the left bank and may possibly be a scuffed piston. As long as I've owned it, the engine has never overheated which they say could have been a cause.
They changed the oil to 5w30 and to see if that helps any. Not too optomistic.
Haven't had any conversations as to what it takes to repair it. Too scared.
S
Senior User
Joined: Mar 2008
Posts: 342
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From: Maple Ridge, Canada
It could be a loose exhaust manifold due to broken studs. Before i replaced the ones on my truck I would hear the manifold kind of clanging upon cold start. After warm up I couldn't hear anything unusual.
Junior User
Joined: Aug 2004
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Have them check the studs before they tell you its gonna take major surgery.
Tuned
Joined: Jan 2010
Posts: 444
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My 01 excursion V10 always had piston slap when it was cold. Sometimes is like pretty bad but it always went away. Can you post a video or sound clip.
Having the dealer diagnose something out of warranty can get expensive.
Having the dealer diagnose something out of warranty can get expensive.
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Tuned
Joined: Oct 2006
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Thanks for all your responses. Quite certain it isn't an exhaust leak. I've had that before and doesn't appear to be the same sound. All bolts were replaced when the used engine (60k miles on it) was put in.
I'm hoping piston slap. Can slap develop over time? Because I never really noticed it this loud before.
I'm going to take it to my regular shop next week and get a second opinion. I took it to the dealer only because of their familiarity with V10s.
Probably something I'm going to live with if their is no chance of it blowing up.
S
I'm hoping piston slap. Can slap develop over time? Because I never really noticed it this loud before.
I'm going to take it to my regular shop next week and get a second opinion. I took it to the dealer only because of their familiarity with V10s.
Probably something I'm going to live with if their is no chance of it blowing up.
S
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Senior User
Joined: Dec 2009
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UPON initial start up in cold weather mine has a slight knock for a few seconds (especially if it has been setting for a few days). I am thinking about putting a little lucas oil in it on the next oil change and see if it helps...
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Do yourself a favor and do NOT use that Lucas stuff. My brother-in-law did to a Ford van with the I6-300, and another Ford van with a 351W, and within a few thousand miles, BOTH of them developed catastrophic oil loss. The I6-300 spun a MAIN bearing (yes a MAIN bearing), the 351W lived but only because it was up in the 180K mile range and was already loose-as-a-goose. Too much of a coincidence to have both engines do it right after using Lucas added according to the directions.
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