Fan Clutch noise on cold start up? Not sure, could use help.

[robinsone]

89 240 230K I was told by a mechanic a number of years ago during cold start up I would get a loud noise from the engine as if someone had inserted a screwdriver into the blades of the radiator fan. It would only happen on a cold start up and rarely once the engine was warm. He said it was the fan clutch and that I was fine and to ignore it. I realize though the difference between the clicking of timing chain at low idle, and this noise could not be it, at least I figure I know the difference. Recently the same noise has now been occurring with greater duration again only during cold start, if this is the fan clutch has anyone else had a similar problem as I really haven't looked into it. I'd love the help. Again I want to separate the notion of the timing chain as this sound is too loud to be it. Thanks.

[TDS]

I say timing chain only because it goes away...

http://www.nicoclub.com/articles.php?id=161689

[Pirate_Freder]

actually i believe that mechanic lied to you or is flat out wrong. i have heard a timing chain that is insanely loud at start-up(like the screw driver analogy you mentioned) and i can't imagine why a fan clutch would make a noise like that. since the chain tensioners are hydraulic you could be low on oil, have low oil pressure(rebuild the oil pump for dual cam or get a new one for single cam, or maybe oil pan gaket or pump pick-up), or just a bad tensioner.

try putting your ear close to the valve cover at the very front of the engine(of course being wary rotating objects lol) and see if the sound is coming from there. ACTUALLY, just go ahead and take off your valve cover and front cover to see if one of your chain guides has snapped(see pic below). the pic shows the top guide which snapped on my ka24de but there also one to the right and down on the side. if either of these have snapped then remove the broken one(s) completely. also check to see if there is where one your valve cover or front cover from the chain rubbing if one or both of the guides have snapped. once you have all tension issues resolved remove those two guides if they aren't already gone(nissan later removed them from the engine design since they are not much more than a hazard, i just think it's better to hit those while your chain is loose rather than letting it flap wildly).

EDIT: if your are around 100,000 miles or more time to rebuild your whole timing chain system with at least new guides, tensioners, and chains and maybe your oil pump too.

[silpena]

hey, does noise start up after like 3 seconds upon start up? /and is ur car auto?

[robinsone]

Guys, thanks for the help, I'm an idiot it is the chain. Right now I'm on my third, the woman before man had the original and ran it into the ground. The shop where I worked in high school bought it from her rebulit it and sold it to me. I added a little more oil and the noise went away at least after start up. I still get a little rattle which I assume is a low initial oil pressure, I assume from the original oil pump with 230K on it, time to replace. Thanks for the advice on the oil pump, I'm going to try and replace the chain myself and will probably swap out a newer oil pump. Can't thank you guys enough I really appreciate the help.