Ominous knocking noise.

[dales33]

So ive been completly rebuilding my front diff/swivel hubs and fitting a lokka over the last couple of weeks and finaly got it back together today.
I fired it up and heard a knocking sound coming from the rear of the motor.
Im almost certain it wasnt there when i parked it up.... it definatly wasnt there a couple of days before i pulled the diff down.
If i put my hand on the spark plug cover above cylinder 5,6 area i can feel the knock but nowhere else on the head , even on the side of the head i couldnt realy feel it.
It leaks a bit of oil and i shut it down and topped it up to full (about a liter) and nothing changed.
If i take the oil filler cap off the revs drop and it idles a bit rough.
Any ideas?
Its my daily driver and i realy didnt need this before xmas.
It hasnt overheated

 

[Dave 2000]

The change of revs/rough idle is normal on sealed crankcase systems, I think that is a red herring.

Is the knock in relation to engine revs, i.e. speeds up when you increase revs.

Any work done on motor while axle work being done?

Regards

Dave

 

[dales33]

The change of revs/rough idle is normal on sealed crankcase systems, I think that is a red herring.

Is the knock in relation to engine revs, i.e. speeds up when you increase revs.

Any work done on motor while axle work being done?

Regards

Dave

Thanks for the reply Dave.
I raised the engine revs a bit but diddnt notice to much difference but my hearing isnt the best.
When i put the filler cap back on it picked up revs a bit faster and the knock got faster aswell.
My problem is the motors generaly in good nik so if i need to do rings and bearings and oil pump i will but all the sane i cant realy aford it.
Id do the head at the same time because i might as well.
Just wondering if it might be a lifter or something and an easier fix

 

[Dave 2000]

Given your hearing it might be worth looking up someone who knows the 80, any MUD members near you?

Regards

Dave

 

[BILT4ME]

The 94 has the 1FZ-FE engine.

Working on the driveline is unrelated to an engine knock.

Did you use the oil pan to jack up the front of the truck? Did you impact the oil pan in ANY way during the work on the axle.

The engine is designed to operate with the oil cap in place. Without it, it will NOT run properly because it is receiving non-metered air into the system and it screws up air/fuel ratios and that's why it runs rough.

A knock in the rear of the engine could be many things.
Misfire on one or more cylinders
Loose bolt on the flexplate to torque converter
Exhaust Leak
Oil in the spark plug tubes causing a misfire

Why are you placing a Lokka in the FRONT diff? That is a non-selectable locker and may cause you SERIOUS steering issues. Especially if this is a DD. You better have lockout hubs and a 2WD transfer case mod if you're doing this on the front.

Could be the wiring harness melted and shorted out over the EGR valve causing injector and misfire issues.

Having rod knock or piston knock on these engines are rare unless they have been abused or run out of oil. The lower end of these are very stout. It's the head gasket that is the weak spot until the original one has been replaced.

Good Luck!

 

[dales33]

The 94 has the 1FZ-FE engine.

Working on the driveline is unrelated to an engine knock.

Did you use the oil pan to jack up the front of the truck? Did you impact the oil pan in ANY way during the work on the axle.

The engine is designed to operate with the oil cap in place. Without it, it will NOT run properly because it is receiving non-metered air into the system and it screws up air/fuel ratios and that's why it runs rough.

A knock in the rear of the engine could be many things.
Misfire on one or more cylinders
Loose bolt on the flexplate to torque converter
Exhaust Leak
Oil in the spark plug tubes causing a misfire

Why are you placing a Lokka in the FRONT diff? That is a non-selectable locker and may cause you SERIOUS steering issues. Especially if this is a DD. You better have lockout hubs and a 2WD transfer case mod if you're doing this on the front.

Could be the wiring harness melted and shorted out over the EGR valve causing injector and misfire issues.

Having rod knock or piston knock on these engines are rare unless they have been abused or run out of oil. The lower end of these are very stout. It's the head gasket that is the weak spot until the original one has been replaced.

Good Luck!

Hi bilt4me.
Definatly no damage to the sump ect and i do look after her well.
Not sure about any mub members near me im in victoria australia.
As for the lokka in the front they are a popular option here.
Its a lockright lokka and they disengage when one wheel gos faster than the other ie turning and suposidly are are far easier on stearing than an e locker or air locker.
The trucks 5 speed manual with part time kit.
Back to the knock... have a guy from work swinging by tomorrow hopefuly with some diagnostic gear we may be able to get to the bottom of it.
Its got me baffled

 

[86tuning]

lucky you guys get 5sp manual hub trucks. none of that's available on this side of the pond

 

[dales33]

Found the problem!
Number 5 plug had somehow come loose and was hitting the plug cover on the compresion stroke
On the lokka...just took it for a drive down a local dirt road and it pulls like a train.
Stearings great and i even drove it home on sealed road with the hubs locked in and still the stearings great. Very happy