1994 d21 4cyl standard 2ws

[Jrb14]

When I start my truck cold there's a rattling sounds for no more then 10 seconds then it goes away. My friend says it's the timing belt. Was wondering if anyone had experienced this issue and what the official diagnosis might be as well as repair costs. Thanks

[PapaSmurf2k3]

Moved to the trucks forum.
The truck has a timing chain, not a belt, but that's what is most likely making the noise.

[Rev_D21]

Two reasons I can think of right off the top of my head. 1) Timing Chain noise. Either due to worn chain guides or low oil pressure. 2) Hydraulic Rocker Arms due to dirt or grime seizing them or causing slow oil pressure to build inside them. Both pretty common for the 2.4L engines in these trucks.

[Jrb14]

alright thanks, is it something that requires immediate attention or can i hold it off for a little while (month or two).

[Rev_D21]

If it only lasts for a few seconds after start up then I wouldn't freak out. Don't ignore it too long of course. If the noise gets worse or doesn't go away at all during driving then I would have more cause for concern. If it's the timing chain guides and they have been ignored for too long the chain will eventually cut into the water jacket on the front cover causing coolant to mix with the oil. Next chance you get to pull off the valve cover shine a light down on the timing chain and have a look at the guides. If they are broken you will find plastic chunks floating around in there.

[Jrb14]

Alright I'll have a look, I emailed a local mechanic and I was told "A rattle usually indicates a broken chain "guide" or Hyudraulic Tensionner Assembly...The front of the engine needs to be completely disassembled to replace either. Due to the amount of labour involved 6.3 hrs best recommendation is to replace as a kit (chain sprokets and tensionner assly) The cost to do this would be approx $1400-$1800 Canadian , all inclusive." Should it be this expensive seems awfully high

[Rev_D21]

Well it is intensive. You will want to do the water pump while you are in there. $1400 is high. I did this in my driveway about 6 years ago. Parts, and I used all OEM Nissan stuff, came out to be about $600. That's because I replaced the chain, guides, water pump, sprockets, every nut, bolt and gasket I could get my hands on. If you are not in a hurry or have mechanical ability there are lots of articles on how to replace the guides yourself. If not I would shop around for the best price.