Strange Jeep noise

[Great War truck]

The jeep has started making a strange sound and I have not been able to work out what is causing it. It sounds like a popping noise, much like lots of bubble wrap being twisted. It goes on for a few seconds and then stops only to start again a few minutes later. I cant replicate it when the Jeep is sitting still, only when i am driving it. It seems to do it most when i am doing about 30 to 40 mph.

 

It is hard trying to work out where it is coming from, but either from just in front of the scuttle or under the floor. I was wondering whether it was petrol leaking and landing on something hot like the exhaust pipe. Or if it was the exhaust pipe blowing. I have had a good look and can see no evidence of what might be doing it. The Jeep seems unaffected by it and carries on at the same speed and power as before. Does anyone have any thoughts please?

 

Thanks

Tim

[commander]

Sounds like a UJ joint to me breaking up on one of the prop shafts

or you are driving in 4 wheel drive

Commander

[Rick W]

Is it fuel? Dont use Tescos fuel, causes problems. Is it mechanical?

[Great War truck]

A U Joint. I hadnt thought of that, but the sound doesnt seem quite right for that.

 

I can only describe it as a constant and very fast, pop, pop, pop, popping sound. It sounds like it could be small drops of petrol igniting as it lands on something hot, but i cant find any leak in the fuel line. It comes and goes and I just cant find where it is coming from. More examination required. I have had enough of it at the moment, so will take another look next weekend.

[Jessie The Jeep]

With the noise only when you are moving, it seems most likely to be in the drive train, suspension, wheels etc. I blew a UJ on the rear prop shaft a few years ago, but from the start of the noise to blowing chunks out of the bottom of the jeep was only about a minutes driving.

 

It would however make sense to carefully inspect all the joints for play/damage. Does the noise still happen if you grease all the prop shaft joints? Or is it any less frequent? That may indicate a pending bearing failure.

 

Same goes for the exhaust system, check for holes, but that seems less likely if it doesn't happen when stationary.

[Nick Johns]

A U Joint. I hadnt thought of that, but the sound doesnt seem quite right for that.

 

I can only describe it as a constant and very fast, pop, pop, pop, popping sound..

Loose spark plug

[Great War truck]

Ok. some good ideas there. I will let you know how i get on. Thanks.

[Blackpowder44]

Ok. some good ideas there. I will let you know how i get on. Thanks.

Our mutual friend Alex had the same noise in his Humber box on the way back from Yeovil. Turned out to be the exhaust manifold had a small crack, might pay to look in that direction. John.

[Great War truck]

Spark pluds are all fine. I cant find any cracks in the manifolds. The U Joints are quite well greased, but i will have another look at them. While looking at the exhaust i found a tiny pin hole in the weld where the flexi pipe joins the tube. As i ran the engine i could feel a little draught coming out of that. I have just packed the hole with Holts gungum and will then take it for a test drive later on. I hope that was the cause of the problem, but it only made the popping sound when i reached about 30 to 40 mph and stopped when i eased off. All good fun.

[Tony B]

I had somthing similar on a car. It was a loose manifold stud. As the pressure increased the stud was stretching' At idle or low speed no noise. When cold everything seemed OK. It increased over time till I found it.