[Hattrick]

Have got a 2000 Series I 4.2 turbo diesel ST. Done 230,000km, and everything is bog-standard, the vehicle never been pushed.
I have a metallic tapping noise from the engine when it's cold, but it seems to go away once the engine is hot. Have checked tappets, and all ok. The motor has had a subtle tapping noise since new (never sorted out by Nissan dealers), but has now migrated to a more metallic sound. A check when cold with an electronic stethoscope seems to have a loud tapping on injectors 2 & 3; the rest are pretty qiuet. Checking around the rest of the block/manifold where I can access, including injector pump, seems to return very little noise. Fuel economy is still around 12l/100k.
Could it be injectors (still original) or something more serious? I'm yet to take it to a diesel specialist.
I know there are plenty, but can anyone recommend from experience a good diesel workshop in Perth?
Gerry

 

[GASSED GU]

United fuel injection will sort ya out,speak too matt

 

[jeffs5]

I had a groove/gouge on one off the tappets and had a tapping noise. No.4 and 5 (valve side) were worn, I linished them back to what the good ones looked like and reset tappets and noise gone. Something too check! Just had a IP and injectors re-built and no different still had tap.

 

[GQshayne]

Not sure how many km's the rocker gear will do before it is worn enough to get noisy, but I reckon that it will be on the high side of 230,000km.

Seeing as you have never had your injectors serviced then that would be the first thing I would get done. They could have been serviced twice by now, so they are due.

 

[GeoffA]

Have got a 2000 Series I 4.2 turbo diesel ST. Done 230,000km, and everything is bog-standard, the vehicle never been pushed.
I have a metallic tapping noise from the engine when it's cold, but it seems to go away once the engine is hot. Have checked tappets, and all ok. The motor has had a subtle tapping noise since new (never sorted out by Nissan dealers), but has now migrated to a more metallic sound. A check when cold with an electronic stethoscope seems to have a loud tapping on injectors 2 & 3; the rest are pretty qiuet. Checking around the rest of the block/manifold where I can access, including injector pump, seems to return very little noise. Fuel economy is still around 12l/100k.............

Hattrick,

Got much the same with mine. Also a Series I 4.2 turbo diesel ST.
It wasn't there when new. It started around 80k, and is still there at 195k, but hasn't really got any worse. It's not overly loud, just annoying. It's louder when the engine is first started in really cold weather, but gets a bit quieter as it warms up.

It seems to be coming from somewhere around cyls 2 & 3, but can't say it's the injectors.

I've adjusted the tappets many times. Even used a dial indicator to set them. They're always OK.

I've had all the rocker gear off to inspect, but couldn't find anything.

I've run the engine with the rocker cover removed, and checked everything with a feeler gauge, and a mechanics stethoscope. All that achieved was I got oil everywhere. The tappets were all quiet, with plenty of oil coming from all of them.

I've put the stethoscope all over the injectors, pump, and anything else I can get it to, but haven't been able to find anything. I'm none the wiser.......

Interestingly, the noise was no louder with the rocker cover removed. I'd reckon if it was coming from the rocker gear, you'd hear it if running with the rocker cover off.

I've noticed several other TD42's making the same noise. If anyone has any experience with solving it, I'm very interested.

Keep us informed..........

Cheers,
Geoff

 

[jeffs5]

It may also be a sticky lifter on the pushrod side, or a damaged lump on the cam.

 

[Nikolay]

WYNNS Diesel System Purge

 

[Hattrick]

Thanks for the replies - some useful ideas.
I used to change injectors on my previous Mav at about every 100,000, but the first change made the engine worse (!). So when I got my GU, I decided to leave them well alone until they started giving trouble (now, maybe?), esp as the engine didn't smoke and fuel economy has been virtually unchanged since new.
A dicky rocker sounds like something I should investigate; certainly worth a try, tho a stethoscope on the rocker cover doesn't seem to pick up much. Anyway, it's no big deal to remove, inspect and re-install the gear. Here's hoping it's not a camshaft issue.
The real knock still seems to be on injectors 2 and 3 with the stethoscope. I'll get the injectors replaced as a matter of course anyway before removing the rocker gear, as they are probably long past the use-by date.
As far as the internals of the engine go, I've meticulously changed the oil every 5k, using Jaso DH-1 spec, but I have noted that when Nissan have serviced it, occasionally they've just used a Fleet-grade oil for both petrol and diesel engines. Another reason for servicing it myself. But there has been that lingering doubt about whether I have something like a broken piston ring or a bearing. When I get the injectors changed, I'll get them to do a compression check and oil pressure check.

As I said earlier, there has been a slight tapping noise since new (since the 10k service actually), and Nissan first tried to isolate it, then basically fobbed me off, saying it was probably the tappet clearances being originally too tight, now normal. Hmmm....
Will keep you all informed on progress.
Meantime, any further suggestions welcomed.
Gerry

 

[poopatrol]

Hattrick,
All td42's make this tapping noise . Some make it louder than others , I've even heard it in civilian buses with the td42 . Mine does it as well and I've tried heaps of stuff to no avail including pulling the head of to check the pre-combustion chambers in the head . All ok there . I think it is something to do with the oil pressure relief system which is part of the oil cooler unit. I have not checked oil pressure yet but do suspect that it might be high when the engine is cold . I got a bit over trying to chase the tapping noise and just put up with it.
I did notice that Nissan did change the oil filter cooler design three times in this engine from early model td42s to late model td42s. So maybe they were chasing something aswell .
Cheers mate.

 

[hodder]

Tapping from engine not tappets

It's the injector pump flicking in the gears. Don't know how to fix it other than rebuild or new gears. Got the same noise noticed when adjusting tappets and turning buy hand from underneath.

 

[DADFA]

Hattrick,
All td42's make this tapping noise . Some make it louder than others , I've even heard it in civilian buses with the td42 . Mine does it as well and I've tried heaps of stuff to no avail including pulling the head of to check the pre-combustion chambers in the head . All ok there . I think it is something to do with the oil pressure relief system which is part of the oil cooler unit. I have not checked oil pressure yet but do suspect that it might be high when the engine is cold . I got a bit over trying to chase the tapping noise and just put up with it.
I did notice that Nissan did change the oil filter cooler design three times in this engine from early model td42s to late model td42s. So maybe they were chasing something aswell .
Cheers mate.

You couldn't possibly be saying that Nissan found something wrong with the 4.2 could you? Isn't that blasphemous?
Are you sure it's not bits trying to get out so it can overheat?

 

[jeffs5]

You couldn't possibly be saying that Nissan found something wrong with the 4.2 could you? Isn't that blasphemous?
Are you sure it's not bits trying to get out so it can overheat?

The tick is nothing , its better than a Bang!!!!!!!!!!!!!!:naughty:

 

[Zoltan]

Before you start spending money on tappets, valves, cams, rockers....just leave it be and you'll get used to it.

I went on a quest to find it and spent about a grand. End result was the same as when I started. Every single 4.2 I have heard since has it at different intensities.

If you are concerned that it might be something bad????....Don't...its normal.

 

[BeNos]

i wouldnt bother about it either really. as long as its not crazy bad then let sleeping dogs lie.
of another note if you think it is injector knock swap the injectors around and rerun it. if the noise moves then you have found your problem. if it doesnt then leave it be.

 

[jeffs5]

Before you start spending money on tappets, valves, cams, rockers....just leave it be and you'll get used to it.

I went on a quest to find it and spent about a grand. End result was the same as when I started. Every single 4.2 I have heard since has it at different intensities.

If you are concerned that it might be something bad????....Don't...its normal.

Thats it!!!!!!! The bloke that done my IP, said all he's done (100's) have it. He put it down to (maybe) One or so off the solid lifters gunked up and the pushrod hitting them!!!! But yeh its there own little song.

 

[Beerhunter]

not sure if this is the same noise but
early td42's had a noise and we worked out it was excess clearence between the lifter
and the block.


i replaced a few blocks under warranty. most people didnt complain but we could hear the noise when servicing them. maybe try thinner or thicker oil and see what happens.


it doesnt cause any problems.