Diesel ticking noise diagnosis

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labsy
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Joined: Sun Nov 02, 2014 9:26 am

Diesel ticking noise diagnosis

Postby labsy » Sat Nov 24, 2018 8:06 pm

Hi,

I know most of you here drive petrol engines, but just maybe somebody might help me to diagnose the issue.

The NOISE description:
Ticking high-pitch precise metal sound (not hissing, not rattling), like tick, tick, tick, coming from engine only under those conditions:
- engine is COLD, so only during winter I can hear this sound
- it does not stop with coolant getting hot, but must drive for 5-10 minutes more with hot coolant for the ticking to stop
- sound does not go away instantly, but rather fades away with engine getting hot
- it is only heard UNDER LOAD and begins at 1900 rpm and fades away if I go over 3000 rpm (diesel!). If I test it in parking lot, nothing unusual is heard even if I rev it up. Simply must drive it uphill to hear that ticking noise.
- when running cold, exhaust smells like shit! There is NO white smoke, but smell is terrible, heavy

- also during summer there's no ticking heard

NOTE: I listen to this sound now 4th winter and it's getting worse each winter. Last year we've done engine service, changed both chains, water pump, all tensioners, head gasket, flatened head, polished valve seats... But we did not touch diesel injectors or lifters.

I've been already at 2 different mechanics, one Nissan dealers, each tellling me the different story:

- one says it is faulty diesel INJECTOR and need to test. Says 300 bucks for test, then 2000 for change if any injector is faulty.

- other says those are LIFTERS. He took my car for 1 week to test and exchange loose lifters, then he said he did it, showed me a hand full of HYDRAULIC lifters, he said he also put diesel pump "in phase", changed oil and filter, changed rocker cover gasket and fuel rail gaskets... and he says the price is 50 bucks. Wtf??!!! It was a rip-off for sure, could not do any of those for 50 bucks, it's just oil that much. And my car dose NOT have HYDRAULIC lifters...bogger!

- and finally, the Nissan dealer said it is chain noise, most probably chain tensioner is faulty and drops down at night, then it needs 15 minutes to span the chain back to proper tension and that's what I hear. But I doubt very much in this diagnosis, because we've changed chains, tensioners and oil pump last year and this specific ticking sound did not change at all, so it is not related.


What I think?
- might be mechanic lifters, although Nissan dealer says they have never ever changed those mechanical lifters on these machines
- still might be one injector. But is it really must-to change ALL if one is faulty?
- I am VERY concerned if this ticking might come from main shaft bearings or rod bearings. Would they be heard only under load and only when engine is cold?


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