Do I need a new tensioner? (pic)

[sean350z]

I've had this terrible metal rattle sound ever since I got the motor (s15 SR) whenever I first hit the gas after starting the car. It doesn't make the rattle at startup, during driving, etc. It only makes it the first time I hit the throttle after starting.

Yesterday I opened the valve cover to inspect everthing and to install some RAS and found that the upper guide had already been removed. The chain was tight. So then I preceeded to center everthing at TDC and the chain would loosen/tighten when I turned the crank. This is a picture of the loose condition at TDC. I counted all the links and everything seems fine (not off a link). So is my tensioner bad and the excess slack causing the intial metal rattle sound when I first hit the gas? Here's a pic.

http://img106.imageshack.us/img106/4977/chaingi8.jpg

[punxva]

i'm not positive, but if its like the ka then it is safe to take the top one off, but dont quote me on this since ive never gone in-depth with a sr

[fico]

the top one is more of a just in caqse kinda thing....so the tentioner breaks the chain has slack boom it jumps cam gears and fucks the timing along with the engine the top guide would help keep that from happening

[projectRDM]

i'm not positive, but if its like the ka then it is safe to take the top one off, but dont quote me on this since ive never gone in-depth with a sr

Tensioner does not mean guide, two completely different things. The guides are removable, but Sean's question was reffering to the tensioner itself.

There's always a little slack in the chain between the cams, if you rotate the crank manually it will tighten up as the cams turn. Press on the tensioner with a screwdriver, if it's easy to push in and there isn't a lot of pressure back, or if it seems to have excess play, replace it.

[sean350z]

cool i'll try that out...thanks russ

[ronj]

These tensioners do not take a lot of pressure to compress. With the tensioner out of the car you should be able to compress it with your hands. Watch out, oil will come sqiurting out of it. I'm sure yours is fine. I would buy a new upper guide for your engine. One off any sr20 will work (sentra SE-R or infiniti G20)

[street_white180sx]

chain sag looks pretty normal i have seen under the valve cover of about 3 or 4 and they all sag like that. that sag goes away when tension is applied from the crank. but if it does rattle on the guide i have heard of ppl removing them before shouldnt hurt.

[kuruptR]

wow someone actually has the same problem as me. The rattleing got so bad i pulled the motor this week end.

This is what i came up with in the end.
I ended up swaping the chain tensioner and all the guides, water pump and oil pump. All brand new from nissan. Cleaned the strainer and replaced all the o-rings. Started this motor, sounded a little better...but it was constantly there...every single light it would go loud and i was pretty ashamed of driving it in public it was so loud....

Conclusion, it was the bearing clearances... the motors oil pressure was way to low, even with the new oil pump. the bearings has to be replaced, they supposedly got damaged from sitting in motor (JDM JUNK YARD). (sezied then shredded on start up)

but i swapped the motor its a lot quiter and im a lot happier. i warrentied the original from the shop i work at. after one year of putting up with the noises.

[sean350z]

It doesn't make the rattle at startup, during driving, etc. It only makes it the first time I hit the throttle after starting

yea i don't have rattling at idle, driving, accel, decel, etc...it's only when i first blip the gas after starting it.

i don't think i have a bearing issue, the car holds 80psi oil pressure cold at the filter and about 20psi warm/operating temp

[HKsilvia]

OMG i cant believe i have the same motor and the same problem with you do.
it actually happen on the first tap throttle after car starts.
i asked one guy who work in a tune shop and he said it maybe the starter gear is loosen or something like that. since its not affecting the driving so now i just light tap the throttle after start up and make it go away.
i also noticed that this problem doesnt happened on cold start (even sometimes it does) it actually occur more often on warm start (like after 0-3 hrs parking)
i will change my timing chain soon and i will see whas happening.

[sean350z]

yea keep me posted on what's going on, that's exactly my deal. i have to lightly and slowly tap the gas pedal for it not to rattle....i guess instead of adding to this thread you can pm me your results

[sblack13]

well with my problem, Its only if the motor is cold. It will rattle on startup then be fine, s14 sr20det.

[bardabe]

Just check oil pressure. Mine use to rattle. REbuilt the sucker. and no more rattleing.