First I would like to think the members of this forum for your help. I had an idle problem and found out it was the lower manifold gasket from this forum. I printed out the instructions that someone had posted on here and they were easy to follow and to a "T". I changed out the upper and lower intake manifold gaskets, but when I started the Explorer it revved high and died then I tried again and it ran so rough I instantly turned it off. So I thought maybe I didn't seat the manifold right or had moved one of the gaskets when replacing the manifold. So I redid the whole thing using the same new gaskets and I didn't find anything wrong, but this time when I cranked it ,it started right up and idled smoothly. Now for my problem. It is now knocking loudly. The knocking becomes more rapid when I give it gas and slows down when it comes back to an idle. I haven't driven it because the knock is so loud I'm afraid of damaging the vehicle even more. It sounds like it is coming from the lower passanger side by the front tire. It almost sounds like it's coming out of the exhaust. I don't know if it was something I did or if it's one of those things that you fix one thing and another thing goes bad. I'm decent at fixing my own vehicles, but far from a pro. I just don't know what the noise could be. Any ideas will be helpful.
It's 1998 4.0 SOHC with 88k miles.
Thanks in advance.

 

Might be a cracked exhaust manifold. Get either a mechanic's stethoscope or a piece of hose and try to pinpointwhere it's coming from. Good luck and please reply with what you find.

 

Do you notice any lose in power when it knocks? Could be something as simple as a loose plug wire, or improper firing order, you could of also cracked a plug. Does is idle fine? And it only begins to knock when you put a load on the engine?? If so someting with your plugs or wires first thing i would check is fireing order if you removed the wires for some reason, then make sure every wire is securly on properly, then i would remove every plug or one at a time and make sure one is not cracked, they are very ez to crack, sometimes you dont know is, even if you not trying to remove just working around them

 

...,


Hey look into another thread with knocking engine with 4.0 SOHC in it. I know I started one. I own a 4.0 SOHC .... I have problems. It is a recall on the timing tensionors and cassettes. There are alot of posts on it. If you have any questions post a reply on this thread and I will give you all the info on the recalls. ......

 

Don't drive it, don't run it. Get it to a mechanic. I hav a '97 XLT with the 5.0 EFI, started knocking. Took it to a mechanic, spun, then fried the bearings on the 3rd crank arm. Just got it back last week.

p.s. mine had 105K miles.

 

Sounds Like My Nightmare That I Can't Wake Up From!!!! :-x01 ..... :-x09 ......barely Going To Drop The Motor Back In And Hope I Don't Have To Bend Over Again..........

 

Lucas Oil Stablizer replace one quart of oil with it. I had ticking and after one mile of driving it was gone after adding lucas--Got it at Autozone for 6.99 I have 150k 98 X 5.0 Its worth the investment

 

...,

Well, thanks for your advice. I had all the recall on it done. I just dropped the motor and so far its running great...I just found a noise when I got home and it is the belt... ..It busted... So, other than that, it is running great...

 

Hi - I have a rattle or something in the right rear lof the engine, sounds like exhaust shield. Could you post the recall info for this 4.0 sohc 98 engine. thanks

 

That is what it was like for mine. The tensioner and the chain cassettes. Did you have this problem when it starts up and or while it is running.????

 

It does it while running, starting is normal. Thanks

 

Lucas may work great for the 5.0 but DONT put it in the 4.0 for the cold start pecking noise...it will make it worse....seems that noise is caused by a semi-clogged lifter and the thick lucas makes it harder for the oil to flow threw...