Knocking at 55mph

[1stgenxsport]

I recently bought a 92 X Sport . When I get her up to about 55mph, the engine knocks/vibrates. It seams like it does it when it goes into OverDrive. Once I floor it, to drop the transmission down a gear, the knocking goes away. What's up with that?

 

['92Bauer]

I recently had a vibration right around when I hit 30 to 50mph and went away after 50. I figured it was worn out u-joints so I took it to my mechanic to have it looked at and what do you know both u-joints were worn out. So maybe you can start there.

 

[MrShorty]

Would you classify it as spark knock? Ping is a common problem on this engine, but can usually be fixed pretty easily. If it is ping, run a search for ping and you should find all you need to know.

 

[1stgenxsport]

I wasn't a ping it was more of a rough vibration @ 2500rpm. I wound up changing the plugs (one of them was cooked) and the vibration went away. Thanks for the help!

 

[Ford_Racing_Guy]

hey that was the same prob i had this last week.

vibrated really bad under slight acceleration in overdrive.

and when i came to a stop i could hear the engine missing.

found a bad plug and changed them all now she runs great again

 

[1stgenxsport]

hey that was the same prob i had this last week.

vibrated really bad under slight acceleration in overdrive.

and when i came to a stop i could hear the engine missing.

found a bad plug and changed them all now she runs great again

I was lucky 'cause I was only able to change the 3 plugs on the drivers side (lack of time and patience). Any pointers on getting to the *******s on the other side?

 

[MazdaGreg]

Saw off all but 2 of your fingers!

 

[foned]

i guess its suppose to be easiest to go threw the wheel well on the passangers side.

 

[MazdaGreg]

On my 93, you can take the upper radiator hose off of the Thermostat Housing, fold the hose up, and that normally gives you plenty of room to get the front 2. The back plug on the passenger side will be tough no matter what you do, but it is possible. i've never looked at going through the wheel well. it seems the manifolds would get in the way, but that's my opinion. My navajo isn't lifted or anything.

 

[svande8952]

It is probably your lifters. It is VERY common on the first gens to have flat lifters. Try MMO.

 

[MazdaGreg]

Huh? Ignition Miss = dirty lifters???

 

[svande8952]

no, the "knocking" might be flat lifters-the original subject of this thread-mine are loud around 55 in OD

 

[1stgenxsport]

Saw off all but 2 of your fingers!

Tried that but the damn ratchet keep falling out of my hand . I will try the wheel well trick and see what happens...

 

[1stgenxsport]

It is probably your lifters. It is VERY common on the first gens to have flat lifters. Try MMO.

Changed plugs...noise gone.