Bad main bearings ?
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Bad main bearings ?
Hello I have a 302 5.0 I bought a couple days ago I noticed a knock on startup and brought it to a shop and was told the main bearings were bad and the engine would need to be replaced. I was wondering if I could get a couple more opinions before I drop 4 grand on installing a new engine !
Last edited by Jdowling2001; May 13, 2021 at 07:34 PM.
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From: South Dakota
Give us some info and we can give you some opinions.
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the truck is a 1995 with 140k on it there is no oil pressure light or any lights on the dash. The sounds goes away when warmed up. I have attached a Vimeo link to the post that shows the sounds on a cold start please let me know if it is not showing.
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I would not be in a hurry to swap engines for a few seconds of startup knock without doing some more diags and getting a second or third opinion from a trusted mechanic.
This sounds more like lifters coming to life, and I would invest in a real oil pressure gauge and plumb that in under the hood. How does the oil look and feel? Crap in the drained oil? You may even drain the oil through some cheesecloth to see what gets trapped.
New motor is pretty pricey unless you are going to keep the vehicle, even then the truck may only be worth 4K to start with .....
Now for a learning adventure, nothing like jumping in and rebuilding an engine.
This sounds more like lifters coming to life, and I would invest in a real oil pressure gauge and plumb that in under the hood. How does the oil look and feel? Crap in the drained oil? You may even drain the oil through some cheesecloth to see what gets trapped.
New motor is pretty pricey unless you are going to keep the vehicle, even then the truck may only be worth 4K to start with .....
Now for a learning adventure, nothing like jumping in and rebuilding an engine.
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Joined: May 2021
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From: Loxahatchee Florida
Drain the oil and look at the oil in the sunlight see if it sparkles.. if it does you have issues..
Unless it was changed by the previous owner very recently the oil will tell you the engines health bearing wise.. cut the oil filter and pull the element out and check for metal in it too
Definitely need to install a oil pressure gauge.. could be lifters like mentioned, could be alot of sludge in the oil pan and blocking the oil pump pick up tube, or the pick up tube itself could be blocked, or your oil pump is worn out.. alot of its to check before you replace the engine..
If the bearings are bad, you can pull the engine and replace them if the crank and rods don't have any groves in them for pretty cheap if your mechanicly inclined
Unless it was changed by the previous owner very recently the oil will tell you the engines health bearing wise.. cut the oil filter and pull the element out and check for metal in it too
Definitely need to install a oil pressure gauge.. could be lifters like mentioned, could be alot of sludge in the oil pan and blocking the oil pump pick up tube, or the pick up tube itself could be blocked, or your oil pump is worn out.. alot of its to check before you replace the engine..
If the bearings are bad, you can pull the engine and replace them if the crank and rods don't have any groves in them for pretty cheap if your mechanicly inclined