Clacking TD42 need help...

[jestaw]

I have this noise coming from my TD42 (1991 - 290km) I have had the tappets adjusted and that fixed the loud part of the noise. I can hear the rest it at idle - just. It is most evident under acceleration 1500rpm+ and just after I back off but not so much when at fast idle. (coming down a hill, no right foot). It sounds like a clacking... tapping but not that sharp - wouldn't call it knocking though. Everything else seams normal - economy = 11.5L per 100km, no oil use (well very little under normal conditions). Pre filter is out, running semi synthetic Penrite. Non turbo. New injector pump but no knowledge of when injectors were last done. Nissan in Wynnum (Brisbane) have told me that it is the valve springs - google reckons it is the rockers that need grinding and the local injector guy thinks it is the nozzles that need replacing...... any ideas....please?? thank you. Jim :drink:

[KRUZIN]

not a zorst leak in the manifold area?

this is a fairly way out there question, but you seem to have covered all the regular ones.

[Peter @ Aawen4x4]

Diesel engines by their very nature have a slight rattly tapping noise all the time, to a greater or lesser degree! The lately introduced engines are really great and the rattle is very difficult to discern at any time other than when you are listening from the front of the engine with the bonnet up, but it's still there! Older engines do it a lot louder, and some really rattle quite horribly, especially if you aren't used to the noise cos you are a recent convert from petrol engines!

I'd take a punt and say that what you are hearing is in fact the normal rattle that you hear from a TD42 regardless! And only cos you are expressing concern is anyone saying that it is anything but the normal rattle. The best way of sorting it out is to listen to as many other TD42's as you can, and see if they run/rattle any differently! I'd be surprised if you found one that didn't have a clearly identifiable rattle pretty much as you describe, and in fact if it didn't have a noise like that I'd suggest that someone has over tightened the rocker gear to buggry and is courting severe engine problems!

If this rattle was loud enough to be heard all the time and both inside and outside the car, it would be likely to be a problem, but you say you can just hear it at idle and it's only really audible under load? I really do think that you are listening to the standard TD42 diesel rattle. Listen to a few others and see if they are worse?!

Cheers!

[A.J.]

Hey there!

My TD42 semmed to have become a little more rattly than it used to be.
Just today I checked/adjusted the valve tappets and a few were a bit loose (not that much though). I set them all at 0.35mm cold and it is now quieter than before but obviously still a little rattly. Standard TD42 I reckon! :D :thumb:

I noticed that when I start listening too much, I start to hear things..... If it doesn't burn oil, is good on fuel and pulls allright, like mine, leave it alone :thumb:

Great donk that old TD42! Mine still looked almost like new when I took off the rocker cover! :waycool:

[dakar61]

Did you check the condition of the rocker faces when you did the tappet clearances?

This will involve the removal of the rocker assy from the head.

The TD42 valves (esp. exhaust) have a habit (when clearances are not maintained correctly) of wearing a valve stem sized pocket in the steel pad in the rocker arm, which makes accurate valve clearance adjustment impossible. When you think you have adjusted the clearance you are really only bridging over the worn area with the feeler blade. When you remove the blade the worn rocker pad drops back down over the valve stem giving you exessive clearance again.

Worth a look if you havent already....

[A.J.]

I did not thoroughly check them but judged by the movement they had they are fine. You get a feell for it if you put a, say 0.10mm, gauge in and then take it out and "rattle".

It was actually the inlet-valves that needed most adjusting.
The exhaust side was quite good. Maybe 2 or 3 valves that needed adjusting.

I set them all on 0.35mm which is the median setting.

Looks like they have been maintained before. But it pays to be safe and do it anyway :thumb:

Thanks for the hint regardless mate!!

[jestaw]

Cheers for responses.
My father has a 89 GQ Td42 cut down to a duelcab and has had it for 15 years - it has never made a noise like this. I have had the tappetts adjusted and that did fix the clear tapping/ clicking noise. The noise I hear is most evident when backing off - just for a second then its gone... and at idle and under load like I mentioned. I discovered over the weekend that it seams to bugger off if it is really pushed. I was over 3000rpm in 1st low - hill climb and it sounded pretty normal. I can really hear it in the morning before it has warmed up. I realise i'm being pretty picky but it just doesnt sound right. :crazy: I am less worried now it has had a thrash round City View 4x4 park.:drink:

- the exhaust manifold seams to be ok
- can still definitely (http://www.google.com.au/search?hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=Aal&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=definitely&spell=1) hear it on the highway and through the revs to 2000rpm (don't see much more than that day to day), just more evident in the afore mentioned.

Thanks for reading and I appreciate the ideas and comments.... thanks

jim

[jestaw]

"Did you check the condition of the rocker faces when you did the tappet clearances?"

no - I didn't, the nissan dealer actually did my tappets for me for free... Have heard that the rockers could use a look - thanks :-)

Jim

[jestaw]

Have had another opinion presented - Gudgeon pins worn combined with injectors needing a service. The noise is not coming from the rocker cover and is directly proportional to the revs, very noticable when backing off - like a rattle... if you've got ideas and opinions i'd be stoked... cheers :-)

[Peter @ Aawen4x4]

Have you had a good listen to any other TD42's yet?? If not, you really hafta do that, or you could be worrying yourself needlessly over a problem that might not even exist! Find a few and listen critically for the same noises. Give it a go, what've you got to lose??

[sc00by]

My engine has a rattle when accelerating and decelerating, its not the 4.2 its a 2.8. aparently my big end bearing is worn or something, still works, doesnt use any oil or water and is still fuel efficient (600ish a tank) i just cant rev it hard.

[dakar61]

I agree with Peter here. You need to listen to and compare other TD42 engine noises. They are a fairly noisy engine even when alls well.

This is due to their very basic, commercial engine type design and constuction, with gear drives, overhead valves, pushrods, solid lifters and no resonant noise insulation like other manufacturers use, all adding to the soundtrack of a normal, healthy TD42.

They are however, as tough as nails and I`d be very surprised if it had gudgeon pin issues.

The situation you describe where the noise tends to be produced on the engine rev rundown is consistent with gudgeon pin wear, but it is a distinctive noise, hard to describe but sounds a bit like piston slap but at a lower pitch. Not tappy like tappets and not harsh like a sticky injector causing detonation.

A sticky injector will tend to cause a harsh rattle on acceleration not de-acceleration, also...

I`d do as Peter suggests and also I`d seek out a Nissan diesel expert (other than the dealer) in your area to listen to it also. We here are at a disadvantage because we cant hear your engine...

[jestaw]

The situation you describe where the noise tends to be produced on the engine rev rundown is consistent with gudgeon pin wear, but it is a distinctive noise, hard to describe but sounds a bit like piston slap but at a lower pitch. Not tappy like tappets and not harsh like a sticky injector causing detonation.


Thanks Dakar

this is EXACTLY what it is... the noise is really there and is not something I'm making up. I have listened to other td42's and am aware of the rattles etc they can make but this "chatter" - hard to explain noise - is there and everyone person - diesel mech, servo mechanic, nissan dealer and the guy who sugggested the gudgeon pin thing have all admintted there is an odd sound. Piston slap has been mentioned also..

I'm about to try some thicker oil - 20w 60 - might shut it up a it.... be an expensive exercise to try and take it further! :-)

Cheers for the suggestions and input.

Jim

[andy_beachbum]

[quote=Peter @ Aawen4x4;709314]Have you had a good listen to any other TD42's yet?? If not, you really hafta do that, or you could be worrying yourself needlessly over a problem that might not even exist! Find a few and listen critically for the same noises. Give it a go, what've you got to lose??[/qu

if you have to run a thicker oil you are only covering a problem, the eng should be able to run on fac spec oil grade i had a same problem until i was on the barge to straddie for another fishing trip and parked next to me was a gq ute same as mine and when it started he had the same noises i did i thought mine was otta wack but normal now i reckon case its judt a trait thing.:waycool:

[andy_beachbum]

Whats the oil pressure at if its normal why switch to thicker oil ??????

[jestaw]

Oil Pressure has always been normal - the last oil change it got penrite 15w50 - I got told by a reputable mechanic in Wynnum QLD that that type of oil was not really designed for older engines and that the 20w60 would be better suited. He also said that the thicker oil would only 'cover' the problem - half of me is CONCERNED that there really is something wrong - but the other half just wishes that nosie would F*&^ off!! :crazy: It just gives me the piss and if thicker oil makes it shut up then I'm pretty happy ... (until something breaks enough to make more noise!). :(

cheers for input :-)

Jim

[4x4boi]

I love the idle rattle that TD42's make for some reason, i would'nt have it any other way!

[Yom]

Mine makes plenty of noise. Have heard plenty of TD42's worse though. I use Caltex Delo400 which is a 15w40 oil. 260,000km. Reco injector pump and injectors only 4000km old (but they're a bit suspect, I've got a tap which goes in the sort of rythm I'd expect from an injector from idle to 2300rpm where the engine noise drowns it out - can hear it best in the cabin. Also have an engine shake under 1700rpm which is likely an injector issue. My injectors are going to be cleanted & tested by the place which fitted them later this month. In the mean time fingers crossed its not a more serious problem - doesn't sound like it tho.)

Doesn't use a drop and performs well. Haven't thrown a rod out the block or dropped a valve in the few times its found 4500rpm in "interesting" situations so I'm not worrying too much. ;) If it is actually wearing out prematurely, what ya gunna do? May as well just drive it into the ground and drop a replacement engine into it when required - these old girls are too old to justify spending $8000 on an engine rebuild.

BTW, you've got a black over pearl grey wagon with the red pin stripe and faded flares too! Nice - just like mine - 'cept mine's a 93 ST with plenty of scrub scratches.

[jestaw]

haha YOM you're right - t'll get driven till it breaks... It has also spent some time with the tacho a little to far to the right! no worries yet (cept for it doesn't like spending time stopped on a steep hill).... anyway, it is an old car, and bloody fun - so let the good times roll. *even if I have to listen to the chatter of a bloody dinosaur under the hood* :thumb:

[Yom]

Just a tip to help you enjoy your vehicle a little more - don't drive it fast.

All it will do is dissapoint you. :)

I rarely rev past 2300rpm in day to day driving now and I usually cruise at 106km/hr in the 110zones as its much more comfortable doing so. Cheaper to run too - I'm getting sub 11L/100km figures for city and highway driving!!!! An added bonus is less wear & tear on the old girl so I guess this is saving me money too.

[netman555]

i think my gq has the same noise as you refer to. After replacing the rockers and rocker shaft,adjusting tappets the noise was still there,oil pressure is 30 psi at idle,50psi all day under load at above 1500rpm,running 15w40 oil.
i have come to think the noise is just the back lash in the timing gears as when you gear shift from 2nd to 3rd gear at about 1900-2500 rpm range,
and the load momenteraly comes off the timing gears,nothing to stress about,
i have driven like it for 5 years with no probs .netman555 nz

[Sea-Dog]

My 80 series with a 1HDT had an erratic knock that came and went as it felt.. like a piston slap.. so I had the injectors cleaned and checked and the knock was reduced heaps.. but still there..

So I have recently replaced my big end bearings and the noise is all but gone!

[jestaw]

i think my gq has the same noise as you refer to. After replacing the rockers and rocker shaft,adjusting tappets the noise was still there,oil pressure is 30 psi at idle,50psi all day under load at above 1500rpm,running 15w40 oil.
i have come to think the noise is just the back lash in the timing gears as when you gear shift from 2nd to 3rd gear at about 1900-2500 rpm range,
and the load momenteraly comes off the timing gears,nothing to stress about,
i have driven like it for 5 years with no probs .netman555 nz

Finally - someone who can hear it! :-) My oil pressure tends to be a little more steady but if what they say about GQ gauges then it means nothing ay. I have pretty much decided to put up with it - I am still on semi synthetic penrite 15w50 as I have only done 4000km on it - at 5000km i'll go the 20w60 and see if it shuts it up a bit... I'm not about to start pulling it apart - its not smokey and the last tank saw 9km/L mostly round town so it seams to be ok (hope that doesn't tempt fate :crazy:).

Thanks for the input!!

[Yom]

why go thicker?

youll just cause problems going to that honey like substance imo!

[jestaw]

why go thicker?

youll just cause problems going to that honey like substance imo!

can't hurt to try... it was suggested by a mechanic that we all know - he almost told me off for using thin oil in such an old engine! hehe... anyway i've had the rocker cover off and it's pretty clean so I don't understand what all the probems will be....? :) only 800km till I find out I guess.

[Yom]

Mechanics, even experienced ones, tend to get carried away with what they think is best.

I'm not slagging them off or anything but when nissan designed & built your motor they figured out what oil it had to run. That oil in our climate is a 15w40. For a 250,000km old motor you could easily push that up to a 15w50 without any hassles but 20w60 is really getting out of the range they figured out this motor runs best with.

But anyway, give it a go and let us know how it pans out.

BTW if you really want to quieten it down, give it forced induction & LPG injecton. That tends to make these old girls much quieter & cleaner.

[jestaw]

I would L O V E to wack a turbo & LPG on it... even with the $2k back I can't afford it... there is no way with diesel prices and my mortgage at 8.44% that it will get any where near that kind of joy. ... AND if I did have the money I'd spend it on buggering off up nth (along with my patience :p). I am pretty used to taking longer than everyone else to get to 60! -

ANYHOO - I didn't know that the afore mentioned shut em up... is it because the whole thing is copping a bit more compression wise and tightening up??? Dunno if that sounds silly but I can't get my Sat night brian to go any further than that... :drink: