Loud Clanking and rough idle

[KelseyM]

I believe I hear it faintly when the engine is at idle, but it really only appears when the engine is under load. If I rev the truck I can hear it but it has to be a pretty high rev.

scatterling- it makes the noise in netural, with or without the clutch in. Yes only on the gas, when I come off the throttle in gear it goes away.

Heres the strange part, I just took the valve cover off (for the 3rd time today haha) and the engine started right up. Idled great, but when I put it back on I couldnt get her to start...

I feel like the sound is coming right from above cyl 2 or 3. I am thinking about pulling the head off tomorrow if its not raining to bad. How big of a task is this that I am thinking of taking on? I mean I know its not going to be done in 10 min but I suppose I dont really have a choice if I want to find out the problem.

[Cutter]

Get an automotive stethoscope and try to pinpoint the sound. I never had issues with the engine not running. The knocking wasnt evident until the oil warmed up and there was a load. I just drove mine until it got so loud I knew exactly what it was, not a great idea. Had to have Matt at Overland rebuild a significant amount of the ways they were so chewed up.

[Momo]

Kelsey, it sounds like a con rod knock to me. Too synchronous and too "dense" a noise to be a loose mount or exterior component. Not pinging, it's too isolated for that. If it is a connecting rod bearing versus a main bearing, that isn't any better news because once you have the bottom end opened up you are going to want to rebuild the whole thing. How much oil pressure are you getting?

[KelseyM]

At idle about 25psi and normal driving 50...I am assuming that to replace both of these I will have to pull the motor correct? I am at work and dont have my bibles with me.

[rwollschlager]

when my head gasket blew this winter it sounded very similar, it idled fine but as soon as rpms increased there was the knock. Check the oil for coolant and the coolant for oil, and do a compression test of each cylinder.

-Rob

[KelseyM]

I will check it out when I get home...

Is it possible the timing chain could have slipped?

[I Leak Oil]

I will check it out when I get home...

Is it possible the timing chain could have slipped?

It's a rover...anything is possible!

[KelseyM]

Haha, very true.

I started the rover up just now, after getting the truck slightly warm so it would stay running(rough) I started pulling plugs to see if the idling would make a difference. Cylinder 1 and 2 did not seem to make any difference when I pulled them.

I am going to pull apart the distributor to see if it is the weights, is there any way to tell if they are unbalanced?

[LaneRover]

Haha, very true.

I started the rover up just now, after getting the truck slightly warm so it would stay running(rough) I started pulling plugs to see if the idling would make a difference. Cylinder 1 and 2 did not seem to make any difference when I pulled them.

I am going to pull apart the distributor to see if it is the weights, is there any way to tell if they are unbalanced?

Not sure about the unbalanced part. Mine were 'frozen' in place. I took them out, sprayed them with 'breakfree' made sure I wiped them off and then put them back. No more dieseling under load.

[KelseyM]

Oh ok, I miss read your previous post. Ok I am going to pull them now and let you guys know how I make out...

I checked my fluid, does not look like a head gasket oil and coolant are clean.

[SafeAirOne]

I checked my fluid, does not look like a head gasket oil and coolant are clean.

That doesn't rule out the head gasket--it could be burned out between your #1 and #2 cylinders (see the non-Rover example below). I'd just do a compression test.

[Bostonian1976]

That doesn't rule out the head gasket--it could be burned out between the #1 and the #2 pistons. I'd just do a compression test.

Mark what do you know about head gaskets?

[SafeAirOne]

Mark what do you know about head gaskets?

Touche.

[KelseyM]

Could be, I just took apart the distributor, and reassembled it. Everything looked to be in order, and afterwards the truck started right up and idled much better than previously. However I could still remove both spark plug wires and it idled the same.

I dont have a compression tester, I will have to pick one up tomorrow

[LaneRover]

Could be, I just took apart the distributor, and reassembled it. Everything looked to be in order, and afterwards the truck started right up and idled much better than previously. However I could still remove both spark plug wires and it idled the same.

I dont have a compression tester, I will have to pick one up tomorrow

But does it still knock under a load?