Knocking 92 MTX

[cams92SHO]

I got my 92 put together yesterday and fired up. There is a hard knock in the rear bank somewhere.....i unplugged every plug wire one at a time while running to see if that would make a change and it didnt. took it back apart and am gonna check the valve clearances. everything looks ok. any ideas what i may be dealing with? maybe a messed up valve?

 

[cams92SHO]

Update:

Valve clearances are within spec (surprisingly) and compression is 175-200.

 

[kevinspann]

Doesn't shock me that they are in spec...how tight is the cam chain? Why was it apart?

 

[cams92SHO]

cam chains are good. the previous owner had the intake and valve covers off cause he thought he could fix it. he gave up after it was apart.

 

[cams92SHO]

well the top end checks out. next thing is checking the rod and main bearings. should be fun.

 

[LOUDSHO92]

How is the cam chain tensioner? If it is bad it would be causing your sound.

 

[rubydist]

I've also had a nasty knock from a loose timing belt, so check that too.

 

[cams92SHO]

i checked the one tensioner that points up and it checked out. is the other pointing the other direction? i think its on the rear head? i did check the condition of the belt but i will check the tension next. just in case, does anyone know where to get a good master rebuild kit? has over 224K

can hear it here
http://www.youtube.com/watch?v=fCIdnYUgyBk&feature=plcp

 

[LOUDSHO92]

We have most of what you need: SHO Source

 

[kevinspann]

Sounds like a rod bearing....

 

[cams92SHO]

Sounds like a rod bearing....

thats what i thought. when i get the time im gonna take the oil pan off and check em. if there is one (or more) spun, how picky is this engine with replacing just the bearings as long as the journals and rods aren't messed up?

 

[jlunde15]

obvious statement is obvious:

Don't drive with a knocking car, otherwise, the engine will be EXTREMELY picky, and you won't be able to just replace the bearings.

</obvious_statement>

 

[sperold]

A rod bearing would quit rapping when you take the plug wire off. And yours did not.

 

[cams92SHO]

obvious statement is obvious:

Don't drive with a knocking car, otherwise, the engine will be EXTREMELY picky, and you won't be able to just replace the bearings.

</obvious_statement>

im not driving the car at all. i got it for free in this condition and the previous owner parked it when it started knocking. it hasnt even driven a mile in this condition. only been started twice since it got it. what are the torque specs/steps for the rod caps? i have heard they have a two stage torque...and i have done repairs like this many times and just dont want to replace the engine

 

[digeronimo34]

I would not bother doing anything else but drop the pan and check the bearing. Save your self time and aggravation.
I have had rodbearings spin three time in two diffrent Engines. That is rod knock. Watch this video to compare Your noise.

http://www.youtube.com/watch?v=vl_IR9LAWsc&feature=plcp

 

[digeronimo34]

This would be a good time to do an atx to mtx conversion. Or just drop another. 3.2 in. Unless you want to pull the crank and replace it or have it ground and use diffrent size bearings . Or you can buy a ground crank with new thrust, main and and rod bearings. I cant find the thread but mabe some one can chime in. The lower rotating assembly is not hard to do. There are some good write ups on it you can find on here

 

[cams92SHO]

This would be a good time to do an atx to mtx conversion. Or just drop another. 3.2 in. Unless you want to pull the crank and replace it or have it ground and use diffrent size bearings . Or you can buy a ground crank with new thrust, main and and rod bearings. I cant find the thread but mabe some one can chime in. The lower rotating assembly is not hard to do. There are some good write ups on it you can find on here

it is an mtx and has the 3.0

any idea where to get a new/reman crank w/bearings?

 

[cams92SHO]

I would not bother doing anything else but drop the pan and check the bearing. Save your self time and aggravation.
I have had rodbearings spin three time in two diffrent Engines. That is rod knock. Watch this video to compare Your noise.

http://www.youtube.com/watch?v=vl_IR9LAWsc&feature=plcp

that sounds just like mine :scared:

 

[digeronimo34]

that sounds just like mine :scared:

I dont remember where but i do remember that someone on here just got the whole shabam. Crank main thrust and rod. Do a surch for it. Or mabesome could chime in here.

 

[shotime1994]

I dont remember where but i do remember that someone on here just got the whole shabam. Crank main thrust and rod. Do a surch for it. Or mabesome could chime in here.

It's not available anymore. Rock auto used to sell it.