88 4.9 Update
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Freshman User
Joined: Mar 2006
Posts: 30
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88 4.9 Update
This is an update on my 88 F150 4.9. It had been sitting a few years, and would not start. We put a new fuek tank, pumps, distributor, distributor module, and relays. It would run 30-40 seconds and dye. I took it to a mechanic buddy, and he fixed the new fuel pump, as it was bad, and then it would stay running, but runing bad. He pulled the valve cover because the was NO compression on the #6 cylinder. He found it had a bent intake pushrod. On further inspection, it had all 6 intake push rods BENT! I think it must have jumped time to bend them all? They are so bent, they will not come out.......we will have to mess with them a while to get them out. Could anything else cause this? Call Me Stumped! THX!
Elder User
Joined: Sep 2003
Posts: 641
Likes: 1
From: Louisiana
If they are stuck, I would not risk doing it any other way than removing the heads and properly cleaning the valve stems and the guides with a reamer. Otherwise you probably will risk bending pushrods again and if they stick open enough they'll strike the top of the pistons and do more damage.
Posting Guru
Joined: Jan 2002
Posts: 1,346
Likes: 8
From: Baltimore
I have a 88 F150 with the 4.9L and was under the impression the engine was a non interference motor. Meaning no matter what position the valves were in, the pistons would not contact them.
The fiber gear on the camshaft on my 4.9 lost a couple of teeth so the crank gear no longer made contact with the fiber gear. You could crank the engine (crank, rods and pistons would move) and the pistons never touched the valves. (Cam/valves not moving).
I wonder if you have an aftermarket cam with a higher valve lift or after market higher compression pistons?
You should post your problem in the 300 six forum and see if anyone has heard of your problem.
The fiber gear on the camshaft on my 4.9 lost a couple of teeth so the crank gear no longer made contact with the fiber gear. You could crank the engine (crank, rods and pistons would move) and the pistons never touched the valves. (Cam/valves not moving).
I wonder if you have an aftermarket cam with a higher valve lift or after market higher compression pistons?
You should post your problem in the 300 six forum and see if anyone has heard of your problem.
