5.4L Engine problem
Thread Starter
Junior Member
Joined: Dec 2009
Posts: 11
Likes: 0
From: G.R.
5.4L Engine problem
Alright so i have a 2000 f150 5.4L, and lately its been missfiring and i have needed to put a couple new plugs and coils in the thing, and recently #3 blew out and they fixed it then it blew out again 2 days later. I do have an exhaust leak on the driver side pretty good and they dont knwo why they keep blowing plugs and why its running liek absolute crap all the time now, im blowing a couple plugs in a week. WTF!? this ford sucks! Any suggestions on what causes this or what is wrong? Thanks!
Senior Member
Joined: Oct 2009
Posts: 893
Likes: 2
From: PA
the reason you plugs are blowing out is because whoever installed you plugs overtorqued them into the heads and stripped the threads. Since the heads are aluminum you have to be careful not to overtorque them. Typically #3 is the most likely to blow out, not sure why but it is the one that blew out on mine.
The reason it keeps blowing out....I am guessing when you say that it is #3 that keeps popping out. It was fixed using a heilicoil, a method that ford does not recommend. The correct way, but very expensive way, is to replace the heads. Thats the reason why everyone just fixes them with a heilicoil kit, like timesert. Unfortunately if the heilicoil kit is not installed well and the plug keeps coming lose. If you want to fix it permanently replace the heads.
The exhaust leak is coming from your exhaust manifold. I am guessing the manifold has gotten pretty rusty and the gaskets have rotted out. It happens on all these engines when the get up there in miles or years. The problem is they are really hard to fix because ford used studs and since they are all rusty they tend to break pretty easily.
The reason it keeps blowing out....I am guessing when you say that it is #3 that keeps popping out. It was fixed using a heilicoil, a method that ford does not recommend. The correct way, but very expensive way, is to replace the heads. Thats the reason why everyone just fixes them with a heilicoil kit, like timesert. Unfortunately if the heilicoil kit is not installed well and the plug keeps coming lose. If you want to fix it permanently replace the heads.
The exhaust leak is coming from your exhaust manifold. I am guessing the manifold has gotten pretty rusty and the gaskets have rotted out. It happens on all these engines when the get up there in miles or years. The problem is they are really hard to fix because ford used studs and since they are all rusty they tend to break pretty easily.