I am working on my 99 F150, 5.4 engine. On a previous post on here I detailed my problem. The timing chain guide broke on the passenger bank, rubbed the cover and the metal filings clogged the pickup screen resulting in 2 chewed up rod bearings.
I am tearing the engine down farther to see what damage I am looking at.
When I pulled the crankshaft sensor tooth wheel I see the chain rubbed the back of the wheel and wore it down some. There are a few small grooves wore in the back of the wheel where the chain rubbed, and the teeth on the wheel are filed down some.
I am having a hard time finding this part, so my question is what is everyones opinion on how bad this will be if I use the old tooth wheel? If I understand correctly the position sensor is basically a magnetic switch that pulses when the teeth pass the sensor, then when the 1 missing tooth passes it changes the frequency of the pulse for that tooth.
When the bearings went, the truck was still running. When the engine cooled down it started and ran fine, no miss or poor running until it warmed up. When it warmed up it still ran smooth but lost oil pressure and knocked.
Also, the engine has low miles. The previous owner said the mechanic that installed the engine ran 10w40 oil in it, and told him it was fine to run that oil so since the rebuild that is the oil he had in it. When I bought it at 35,000 miles on the engine approximately I drained that oil and went back to the specified oil. I am thinking the wrong oil allowed the chain to run loose on startup. For a few weeks before the bearing went I heard a rattle on that side when I first started it.

 

On the oil situation, the first mistake was the mechanic telling the previous owner to use 10w40.
The spec oil is 5w20.
What happens is the heavy weight oil especially on cold starts puts to much tension on the cam chains and the tensioners and wears them way to much.
Now 'you' have the problems and cost/hassle from it.
As a result tear things down, inspect and replace as needed to try and get some long life out of the motor without having to keep fixing things all over again each time.
.
On the crank sensor timing wheel, find one somewhere even if from a yard.
This sensor is the 'reference' for 'all' other operations.
If there is a failure or lack of sensitivity due to teeth spacing, missing or run-out nothing works or work reliably.
Good luck.

 

Thanks for the input!
I will see if I can find a replacement tooth wheel. I have not checked the parts stores in person, just their online inventory. Sunday I am going to go order my parts. Maybe they have one of these that is not listed on their online inventory. If not I will check directly through Ford.
I did not know the possible damage that 10w-40 could do to these engines until I started reading and posting on here. I did switch back to 5w20, now I know why.
So far I have torn it down to see what all is damaged.
On here I was advised on another thread to replace the cam bearings, but discovered this engine does not have cam bearings. I did pull the cams. The surfaces where they mount are in very good condition. I did not find any scoring, heat damage, or signs of lack of oil on either the cams or the head surfaces. There was oil still in the friction surfaces, so it was getting oil. I wiped these with a clean rag and checked the oil and rag for signs of metal. It looked clean. I cleaned all surfaces, will lube with assebly lube when it all goes back together.
So far the damage I can find is isolated to the bottom end. The timing chain guides are both bad. One is broke the other is chewed up. The timing cover has wear marks where the chains rubbed. The gear tooth wheel is worn. I am not sure how to test the tensioners, the hydraulic pistons that put tension on the chain with oil pressure. When I push them they go in and pop back out?
The oil pan has metal filings in it. The pickup screen was clogged. 2 bearings are roasted, looks like they ran without oil.
So far I am replacing the crank, bearings, oil seals, timing chain tensioners, oil pump, and the tooth gear.
Also, I have been told the oil pan gasket, valve and valve cover gaskets can be re-used. This doesn't sound right. Is this correct, that I can re-use them? It would save a lot of money if they can be re-used, but I hate oil leaks!
Thanks for the input!

 

The rubber oil pan seal can be re-used, but you should look at it and make a determination whether age and oil have been too unkind to it. A 2 year old oil pan seal is one thing, a 15 year old one may be another.

Just curious, I didn't see the chains on your list. Is it worthwhile to replace them seeing as they have been used as a chain saw?

 

Yes chains too.
The oil pan gasket looks good. No rough spots or other wear. The engine is a rebuild, I think 4 or 5 years ago. I am not certain of the miles, my odometer only works when I hit a bump but somewhere between 50,000 and 75,000 miles on the engine. I have all of the paperwork on when the previous owner put the engine in, and it is written in grease paint on the firewall at 111,000 miles. It now has between 70,000 and 75,000 miles I think. I haven't had a battery in it since it broke down early this summer.
I don't see any obvious wear on the chains, they look good as new, but just in case they were weakened by rubbing.
Oh, and I also need a book. So far I am going into it blind, and by what I find online!