2005 Cold Start Knock-Rattle

C
Last seen
Joined
Sep 20, 2018
Thunderbird Year
none
Engine ran hot now makes a knocking/rattling on cold start SOMETIMES not every time. Drives fantastic, plenty of power. Secondary tensioners were replaced at some time. Both chains are tight. Quiet after initial start, won't knock again unless it sits overnight (sometimes not every time). Listen please and let's figure this out.
 
Hi.
It sounds like bearing knock. After sitting for some time oil runs back into the sump, then when started it knocks until oil pressure builds. Is it a high mileage motor? Did it just start knocking after it got hot? How hot did it get?

John
 
Engine ran hot now makes a knocking/rattling on cold start SOMETIMES not every time. Drives fantastic, plenty of power. Secondary tensioners were replaced at some time. Both chains are tight. Quiet after initial start, won't knock again unless it sits overnight (sometimes not every time). Listen please and let's figure this out.

Hello, did you ever figure out the issue? I have a 2004 with 39K (bought it 5 years ago with 18K) and all of a sudden last week it started making a similar rattling sound on cold starts. Runs fine otherwise. Haven't completed the diagnostics that you have but did check oil level and it is fine (regular oil changes, car does not leak, doesn't burn oil that I can determine as level is always in range between changes). Odd that it came out of the blue. Only thing I can think of is that it started after the zero degree weather we had in Dallas in February. The car is often only started about every other weekend, so it does sit quite a bit. Thanks.
 
My 2004, now with 39K miles, suddenly started dong this a few weeks ago. I've had it five years, purchased with 18K miles, never made any noise when cold starting, even after sitting for weeks as it often does, then out of the blue one day - rattle! And quite loudly, lasted for a good 1-2 seconds. Runs all right, doesn't repeat when restarted later in the day, only cold start after sitting for many hours. Checked oil level and fine, no leaks, no evidence oil burning and level never needs topped off between starts. Every oil change since I bought it has been a local Ford dealers using OEM filter. Replaced all 8 spark plugs and COPS last fall and car has been running very well. Anyone ever figure out what this is? I like the car but am now tempted to trade for a new Mustang.
 
I have heard that the variable valve timing mechanisms will do this when the oil drains out of them.
 
Its not just variable valve timing; this is what I heard one morning 6 months ago when I started the 2002, 31,000 mile Tbird on a cool (not cold) morning:


Pretty frightening but it quieted down some after the car warmed up. I went total "old school" and put a bottle of Marvel Mystery Oil in the cranckcase and things got quieter after about 150 miles, followed that up with a treatment of Seafoam additive and there is no, nada, zero noise now, about 500 miles later. Letting these cars sit for months/years doesn't give them enough running time to clear out sludge and deposits and such things as this are the result.
 
be sure to use the correct oil in colder climates, 5W- 20 oil. A thinker oil will not get thru the small passageways and can cause the knocking sounds.
 
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