Knocking

[rathrbcruisin]

Great, this freakin thing is really pissing me off. Paid top dollar, I think, 3200 for this nice Eddie Bauer explorer with the 302 specifically bcuz of the "bullet proof" setup of the v8 and transmission. Put a little money into getting the CEL to go off bcuz of O2 sensor and then there was a hole in the vapor canister. Now after it is warmed up I'm getting a knock. It will not do it cold, and if its doing it and you shut it off and start it again it will not do it until you drive it a little. I bought some Lucas oil treatment to put in it as I'd like to make it to 200,000 miles, I'm at 140,000 now. It had 135,000 when I bought it. It was from the original owner and he had receipts for oil changes so I don't know what the deal is. I used valvoline maxx life 5w30 at 138,000. theres no telling if he dumped something in the engine to unload it to someone. I've been pretty lucky buying older vehicles but I may have gotten screwed on this deal. Most things about this truck are great. But I sure don't want to put another engine in it. That would blow my entire reason for paying so much for this truck in the first place. Sure hope that Lucas oil stuff works.

 

[masospaghetti]

You sure its a bottom end knock? And not an exhaust manifold leak?

As far as drivetrains go, the 5.0 + AOD is about as "bulletproof" as you can get - especially if the previous owner cared for it.

 

[Turdle]

Yup
egr tube or cracked manifold leak, especially on a 98 with tubular manifolds. Most end up looking like this.

 

[rathrbcruisin]

I had the egr tube replaced. I didn't think an exhaust leak would sound like a knock. Why wouldn't it be worse when cold than hit? I'll have to dig into this a bit. I don't think the Lucas will hurt though.

 

[rathrbcruisin]

I bled off some oil and put a quart of the synthetic lucas oil treatment in it. I dont think it made much difference. Maybe a little quieter, maybe. Just gonna drive it and see what happens I guess. Not much else to do. I had a buddy get his ears on this too and it almost sounds as its coming from the front, then if you go to the drivers side rear of the engine it sounds like its coming from there. crazy. when its doing it and you bring up the rpms, it doesn't really increase like you think it would. I'm thinking thats a good sign.