2002 F150 4.6 Timing Chain Replacement
#1
2002 F150 4.6 Timing Chain Replacement
Hi Folks...I'll dig right into this. I have read through Browneye9000s post on this topic from 2008. I am pretty much right where he was in mechanical experience. Are there any other posts on this site that detail this "operation" ? My truck has 200000 kms on it and it has just started to give that nasty rattle at the front end of the motor. It actually started a week ago. I have not driven it except back and forth from my mechanics place where he confirmed the diagnosis. It still has lots of power, and idles well. The check engine soon light has come on.
Here's my dilemma. My mechanic is afraid that the valves have come into contact with the pistons, and he doesn't want me to waste my money opening it up to find out. He wants to pick up a used motor and swap it out. The truck has a 5 speed manual transmission in it so if we are motor swapping we may as well change the clutch at the same time. I'm looking at a cost of $2000 to $3000 for the motor swap depending on the cost of the motor I find. However, it doesn't make sense to me that if the motor is still running well, and the rattling in the front end just started, how could the valves come into contact with the pistons at this point? If that had happened, the engine would be running very rough, if at all. Any thoughts on this would be great.
Here's my dilemma. My mechanic is afraid that the valves have come into contact with the pistons, and he doesn't want me to waste my money opening it up to find out. He wants to pick up a used motor and swap it out. The truck has a 5 speed manual transmission in it so if we are motor swapping we may as well change the clutch at the same time. I'm looking at a cost of $2000 to $3000 for the motor swap depending on the cost of the motor I find. However, it doesn't make sense to me that if the motor is still running well, and the rattling in the front end just started, how could the valves come into contact with the pistons at this point? If that had happened, the engine would be running very rough, if at all. Any thoughts on this would be great.
#2
#3
well...I may be a bit guilty on the oil side of things. I don't use the truck in the winter as its two wheel drive and stupid in the snow. I had the oil changed last fall but have not had it done yet this spring...probably 6500 kms on it since the last change. It was down a liter the other day when the rattling started. The noise is pretty central to the front end of the motor...maybe a bit louder to the passenger side. I'm really leaning toward taking this apart and fixing it myself...but I don't know how to tell if the valves have hit the pistons. The motor is still strong so I don't think that's happened yet.
#4
No the valves are not hitting the pistons or you would have a lot bigger problem and the motor would not run well at all.
There are 2 timing chains one for each bank.
They are tensioned by the oil system's pressure against a piston operated tensioner for each side.
The tensioners are lined with non metallic forms.
When they wear the chains get loose and may slap against the front case cover.
Since they just started, don't run the engine any longer until you do the repairs to prevent more damage and other possible issues.
As it wears, the materials collect in the area and even drops into the pan.
It might be worthwhile to test actual oil pressure before you take it apart to see if an oil pump may be part of the repair because it's right up front on the crank.
Another point is, hope you have not been using heavy oil from the spec of 5w20 because it puts more tension on the Tensioners than is needed especially on cold starts.
To offer support, my engine is now at 250,000 miles plus and still quiet on 5w20, all year around.
Good luck.
There are 2 timing chains one for each bank.
They are tensioned by the oil system's pressure against a piston operated tensioner for each side.
The tensioners are lined with non metallic forms.
When they wear the chains get loose and may slap against the front case cover.
Since they just started, don't run the engine any longer until you do the repairs to prevent more damage and other possible issues.
As it wears, the materials collect in the area and even drops into the pan.
It might be worthwhile to test actual oil pressure before you take it apart to see if an oil pump may be part of the repair because it's right up front on the crank.
Another point is, hope you have not been using heavy oil from the spec of 5w20 because it puts more tension on the Tensioners than is needed especially on cold starts.
To offer support, my engine is now at 250,000 miles plus and still quiet on 5w20, all year around.
Good luck.
#5
Thanks Bluegrass!!...that's what I wanted to hear. I've had the truck for two years and have only ever used 5W20 in it. I'm not sure what happened b4 I bought it, but it has certainly run well for me until now. There are a trio of videos on YouTube by A1 Auto that seem to make the repair pretty clear.
#6
Join Date: Dec 1997
Location: Windsor,Ontario,Canada
Posts: 9,417
Likes: 0
Received 11 Likes
on
10 Posts
Your engine is an interference engine. That means that if the valve timing gets out of synk enough the valves will make contact with the pistons. If that had happened you would be telling a different story. Part Source should have all the parts you will need and they also have a shop manual look up so you can print out the procedure.