I was recently given an 87 ford f150 4.9L 2wd standard transmission by my father in law. It was not running at the time but I have recently got it to start up. Since it starts now the real fun begins in trying to figure out what's going on with it. So with that being said here goes.

So when it starts up(cold) there is a popping noise that seems to be coming from the carb. Now here is what's funny once you turn key and start it up it revs up and it's fine but when us tap on gas it pops and loses power like it is going to stall then it picks back up(most of the time). I have changed the spark plug and wires along with the distributor cap. So I am at a loss as to what to check next. Any leads or answers would help.

Now issue #2, there is a loud knocking sound coming from that passenger side go the engine. It is not in any real rhythm but some times it does sound it is. If that makes any sense. I have read that it may be due to water in oil since it sat so long so I changed oil yesterday and started it up. It appeared to have stopped it for a few seconds then it stared again. Any ideas as to what may be causing this?

Now issue #3, when the truck is on the truck will not go into gear. It will grind the gears as if the flywheel is still spinning. When the engine is off it slides into gear fine. Also when trying to put into gear the engine rpms go down. Any help with this would halo as well.

Thanks in advance for any help.

 

Issue #1: First of all, are you certain the truck has a carburetor? I believe that a '87 4.9L should be EFI. Any CEL's? Have you tried pulling codes? Checked for vacuum leaks?

Issue #2: Cut open the oil filter and check for bearing material in the filter media. If you still have the old oil, inspect for water, coolant, and bearing material. If you're able to post a video of the knocking, it would be helpful in diagnosis.

Issue #3: The clutch isn't disengaging completely. Have you checked the fluid level in the master cylinder? Have you tried bleeding the system?

 

Max- I stand corrected it is an EFI I just remembered. I have not pulled any codes as of yet but I will be sure to do that.

I do still have the old filter and I will cut that open today and check the metal. When I drained the oil it appeared to be free of any water or coolant it was just really dark like it had not been changed for a while.

The fluid level is full and I have not bled the system. How would I do the bleeding. If you don't mind me asking.

 

You should see the bleeder on the left side of the bellhousing above the hydraulic line.

 

Ok thanks I will go out and see if I can get this done and follow up on some of your other suggestions as we'll and post an update thanks for your advise and I hope I can get this truck up and going

 

Ok so I have video of the truck how do I post it

 

Host it on a site like Photobucket, then post the link here.

 

Ok I am trying to get it uploaded on the YouTube site

 

Here it is

 

Here is another video

 

Yup sounds like ya got yourself a stuck bent or burnt intake valve there, compression test will tell you which hole needs attention.

Can often free one up if stuck from just sitting, one won't close all the way but nothing else wrong with it, but would have to determine that as the problem first.

 

Can that test be done at home or would I have to take it to a shop

 

Ok so is it freeing it up by sitting or hitting? Also will this cause any further damage to engine

 

You can do it, remove valve covers and all the spark plugs do a compression test.

Need a compression tester (a screw in type is best), block throttle wide open and unplug coil, remove FPR.

Have assistant turn it over, test each cylinder allowing 3 compression building strokes min then record the value. Start with cylinder 1 end with #8.
You want it to turn over and strong start to finish, connect a battery charger to battery during testing keep battery up while cranking.

Watch the rocker arms/valves in action while its turning over, make sure each valve returns to its fully closed position and just in general watch for anything looks odd/off.

Odds are you're gonna end up replacing a head or heads but that will get you a starting point, one bank or both have issues and if only one which one and which cylinder is it go from there.

 

Ok so would it be cheaper to replace the heads or to replace the engine. I have never torn an engine down that far so I am kind of hesitant to do it. I know I could do it if I followed it step by step. What are you alls thoughts