Noisey when cold

[BrianW5]

Hi guys.

I'm new to the forum but not new to Navara's, or Nissan in general for that matter. For years i had a D21 with the ultra reliable TD27 workhorse, but recently upgraded to a D22 with the ZD30.
It runs fine, and ive just done the egr thing, but i'm wondering about how agricultural it sounds. Until it warms up it sounds like a Massey Ferguson tractor. Is this normal? Are they usually a rattly bugger when cold or should i be looking at valve shims and injectors etc?
Apart from being able to accelerate quicker on a push bike when cold, the trusty old TD27 was never this loud.
My work truck is a Colorado with the 3.0L Isuzu engine and its as quiet as a mouse compared to this.

 

[tweak'e]

sounds are very hard to diagnose over the net.
they certainly have there own sound, especially when cold. however can't tell you if yours is normal.
video of it may help.

the only thing i can think of at the mo is that injectors may be worn or injection pump failing.
injection pumps in these are a common problem.
try changing fuel filter and check for air in fuel line.
if timing is retarded due to worn pump/blocked filter/air in lines then it may sound noisy when cold.

 

[BrianW5]

Thanks. Ive just done fuel and oil filters, so that shouldn't be an issue. I did wonder about the injectors, they've done 230k, but hadnt thought about the pump. Its not overtly loud, or sounding terminal, but its very reminiscent an old non turbo, 40's tractor starting up on a frosty day. I do think there may be some shim rattle going on, but given that in my experience with cars and bikes etc, shims can be mongrels to change so the rattle might be staying around for a while.
I'll try to get a video of it in the morning before the wife buggers off to the horse paddock.

 

[D21-DX2.7D]

Might need its idle dialed up, the choke is the best feature in a td2.7and wish nissan kept it on as I would've bought a newer navara. IMO I just think the computers idle too low to save fuel on the zd30 and the 2.5

 

[BrianW5]

Its not really at idle where its noisey. Its mostly under acceleration when its cold. It sounds like a baked been can full of stones until it warms up. Its fine if we start up and leave it idling in the driveway to warm up for 10 minutes first.

 

[jonney]

if this model d-22 has a hydraulic chain tensioner , i am wondering if it could be that causing the noise on cold start ups and when the oil gets into the tensioner all is then fine.

 

[BrianW5]

Good point. Worthy of a look. Do they Have hydraulic tensioners?

 

[happy john]

Tappet noise, any ZD owner will know that.

 

[jonney]

someone should be able to say if your engine has a hydraulic timing chain tensioner plus as mentioned it could also be tappet rattle on start up so maybe get the these adjusted and see how things go . oil and oil pressure has alot to do with both cases.

 

[BrianW5]

Oil pressure's fine and oil is new, and correct grade. Tappets are a definite possibility but the noise is a little harsh and loud for it to be just tappets, unless were talking 20 or 30 thou, but at that the engine wouldnt be running as smooth as it does.
The more study i'm doing on these engines, the more i'm thinking injectors. If the fuel isnt atomising well in a cold cylinder in a low compression engine, the more diesel knock there's going to be.
I understand that ZD30's are noisier than most, but this one is noisier than i think it should be. Going to take a couple of injectors out next week and have them pressure and spray tested. Probably up for new ones but there's a local specialist here that overhauled my TD27 ones a few years back. Will give him a look first.

 

[happy john]

Brian are you able to upload a short clip as Tweaked mentioned?, the ZD has a very pronounced tone unlike the smooth TD27 you have come from.

 

[tweak'e]

i forgot the basics......glow plugs.
you may have dropped a glow plug or two. not enough to cause start up issues but can make it loud running.

chain tensioner you normally notice in the first few seconds of starting the engine. the engine noise changes abruptly as oil pressure comes up.

the other thing is if you have access to a scan tool, get a read out of the ICV% at idle.

diesel don't have a choke as such ie no change in fueling.
not sure with TD27 but VE pumps have an option of a thermostat which advances the timing when cold (theres a few different ways of doing it).
of course the ECU does all that on the later engines.

edit: i forgot the injectors are dual stage. often the pilot injection spring goes soft. the pilot injection is what helps reduce combustion noise.

 

[happy john]

A broken glow plug will provide more than noise, it will fucck your cylinder very fast.