[shaagger]

after sitting overnight or long enough in the winter to fully cool down, the engine knocks for a minute or so, length of time knocking is dependent on how cold it is outside and how long the car has been sitting.
If started after sitting out overnight at below 20 deg F it will knock for nearly 5 minutes before completely quieting down.
It sounds like piston to cylinder bore or wrist pin to piston?
Doesn't sound like a rod or a main and it has great oil pressure when cold.
Anyone have any experience with this type of knock?
It has been doing it for about 2 years now but it is steadily getting worse, knocking longer on start up.
I would like to get it fixed if possible??
thanks

 

[Submariner409]

Do some searching in this forum and Tech Tips. I believe the 4.9 is noted for a cold start #1 main bearing knock.

 

[cadillac_al]

I hope your oil isn't too thick. I used to run synthetic in the winter to make engines turn over easier. Now I run it year round.

 

[shaagger]

thanks will do

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I am using Pennzoil 10W-40, maybe will give mobil 1 a try on next change??
I have an oil pressure gage installed and it makes almost instant oil pressure (20 PSI) and builds quickly from there to about 70 PSI in under 10 seconds, so I am thinking it is getting plenty of oil such that it shouldn't knock for 5 minutes??
But at this point I am game to try anything.
thanks for the suggestion

 

[MoistCabbage]

Synthetics flow better than conventional oils in EXTREMELY cold conditions. In normal winter conditions, the difference is negligible.

 

[cadillac_al]

20 below qualifies as extreme for most people. In my experience it is noticeable at 10 degrees f and lower.

 

[shaagger]

all; I did an oil change last weekend and went with Mobil 1 10W40, unfortunately it had no affect on the cold start knock?
bummer

 

[MoistCabbage]

20 below qualifies as extreme for most people. In my experience it is noticeable at 10 degrees f and lower.

I missed the 20 below part.