Outer Limits 4x4 Board

Hi guys, Over the last year i have had a tapping noise in my engine which i have came to belieive is worn lifters. This is due to the fact that i have had my tappets done and the ticking noise comes from the bottom of the block instead of the top of the block which could be rockers and rocker pads.

I just have a few questions:

-How much should they cost to replace? I know the parts are around $400, however, it is the labour involved which will cost. I went to my local mechanic and he suggested i was up for $1500-2000, which i thought was prettry steep.

-Are worn lifters that detremental to the motor, or should it be done straight away.

-Is it that hard off job, as my mate works for cummins deiesel and the only thing he was concerned about doinfg the job was maintainig tension on the timing chain.

cheers
cuzza

Sorry guys, i forggot to mension its a td42 out of a GQ

Personally, i dont think it will be the lifters. These are not hydraulic lifters, and i believe they are solid, hence the reason for tappet adjusment.

I also thought that it was wierd, especially because i only have 180,000km on the clock and i have owned it from 30,000Km with regular services. I have been told by 3 mechanics now that they think it is lifters, mainly due ot the fact that the noise derives from lower in the block.

The noise is intermitent, in that you can not here it when it is ideling, however, around 1100-1200 revs there is a tapping noise that occurs. The noise is not contant at ceratin revs and constant at others. The only other alternative is worn cam lobes from what i have been told.

hows the oil preasure?

I think the oil pressure is good. Its takes only a few seconds to rise and when on the highway its sits at just under 4 when warm. When warm and idling, it sits at around 2 on the standard nissan gauge which from reading my gregorys manual is acceptable

I think the oil pressure is good. Its takes only a few seconds to rise and when on the highway its sits at just under 4 when warm. When warm and idling, it sits at around 2 on the standard nissan gauge which from reading my gregorys manual is acceptable

Engines either have adjustable tappets or hydraulic lifters...not both. As the td42 has tappets and you reckon the noise is coming from the bottom of the block, at a guess I would say (and I hate being the bearer of bad news) you have bottom end problems. If left unattended you may find one of the pistons trying to escape from the side of the block sometime soon. Best bet, get it to a reputable mechanic for proper diagnosis asap.

Is it not possible, even though the lifters are not hydraulic that they would make a tapping noise. If it is the botttom end, am i looking at a bottom end rebuild and if so how much do you think ths could cost?

Is it not possible, even though the lifters are not hydraulic that they would make a tapping noise. If it is the botttom end, am i looking at a bottom end rebuild and if so how much do you think ths could cost?

I doubt very much that it will be the lifters. Depending on how many km's the engine has done, the worst that it will have is worn lobes on the camshaft. When i rebuilt my TD42@550,000KM's, my camshaft had slightly worn lobes, but lifters were all ok. I had some badly worn valve rockers which made adjusting tappets very difficult and time consuming.

I ended up replacing the rocker shaft,which was pretty worn and all inlet and exhaust valve rockers after the rebuild. Inlets are cheap (relatively) but exhausts are expensive--nearly $90 each. Camshaft bushings are very difficult to replace though.

Nick

If its not the lifters what could the noise possibly be coming from?

cuzza wrote:If its not the lifters what could the noise possibly be coming from?

Maybe worn camshaft lobes, maybe a slightly bent pushrod. Worst case scenario, it could possibly be the crankshaft bearings, and although I can't really describe the noise, it usually does'nt sound like tappet noise.

I'm going to state the obvious. Before you do anything disconnect the fan belts and make sure it's not noise emanating from any of the ancillaries like water pump, ac, alternator, idler pulley, viscous fan etc first.

It could be a worn injector. SOmetimes these can sound like a flogged out big end bearing.

Nick

I just had my injectors replaced 15,000km ago, and its not coming from the water pump or any auxilary parts. I will take it ot an diesel engine rebuilder tommorow to see what they think the noise could be. Thanks for the replies guys.

cheers
cuzza

raptorthumper wrote:I'm going to state the obvious. Before you do anything disconnect the fan belts and make sure it's not noise emanating from any of the ancillaries like water pump, ac, alternator, idler pulley, viscous fan etc first.

Yer, and a small exhaust leak can sound amazingly like a metallic tapping noise too.

Good luck with this. Have you tried the listening-through-a-rubber-hose and listening-through-a-screwdriver approaches? Noises in the engine bay as Raptorthumper says can be really deceptive. Putting a rubber hose in your ear and pointing it at various spots can isolate the noise much more than just leaning in.

I have noticed that the noise is more prenounced on the left hand side of the engine bay where the extractors are. I took it to an engine rebuilder today who suggested that i should forgget about it for the time being as it was high pitch and not a low pitch thud. He said only if it gets louder and can be heard under load should i worry about it.

Nevertheless i will take it to another diesel mechanic for a second opinion. Does any one here know a good diesel mechanic in perth who would mabye be able to help me.

cheers
cuzza

I have noticed that the noise is more prenounced on the left hand side of the engine bay where the extractors are. I took it to an engine rebuilder today who suggested that i should forgget about it for the time being as it was high pitch and not a low pitch thud. He said only if it gets louder and can be heard under load should i worry about it.

Nevertheless i will take it to another diesel mechanic for a second opinion. Does any one here know a good diesel mechanic in perth who would mabye be able to help me.

cheers
cuzza

love the double posts

love the double posts