Chain or VVT Rattle

[S15_Spec_R]

I have done a search and not found what I am looking for regarding the above. I thought I had already asked about this but I cant find it. About 3 months ago I was getting a tick/rattle which under closer investigation looked like it could be the water pump impeller as the shaft had some play and I was loosing water.

Well I fixed that with a new pump, however the rattle is there now and again which leads me to it possibly being the above title. Sometimes it will rattle (sounds chain like) from cold start but after 15 seconds it goes. While rattling I have engaged the gears while stationary but no change.

The rattle then comes back when I least expect it and seems to be linked to oil pressure and temp. If the temp is 80cent oil and around 2bar pressure it sometimes rattles. I increase throttle and just under 3bar the noise goes away.

I have serviced the car regulary maybe too often (1500 miles) because what I thought was flat 3 years ago actually runs so I get oil retention in the sump and I think the oil cooler holds oil as it is thermostatically controlled. So for 3 years I have been putting engine flush in with every change and not getting all the oil out, which would explain why my oil would get dark after a few hundred miles.

I heard about a solenoid connection for checking the vvt but dont know what I'm looking at. Just could use some info as to diagnose as after reading some of the results on here maybe this rattle is causing bits of metal to get closer to killing the car. One thing I know is that oil pressure and its temp seem to be a major variable.

Sorry for the long entry but I dont like pulling up at lights or wherever low revs are with what sounds like a diesel!!! Thanks, K

 

[mrpham]

Hey mate.

The rattle problem is associated with the VTC system, it can either be the solenoid (the thing poking out of head on driver's side) or the actual VTC cam gear it self. It's most likely the VTC cam gear but you can check if it's the solenoid by simply unplugging it. If the noise disappears when you unplug the solenoid cable then you'll know it's the solenoid that needs replacing, if there is still the rattle noise then it's the VTC cam gear.

http://www.frsport.com/Genuine-OEM-Nissan-Intake-VTC-Cam-Sprocket-S14-S15-SR20DET_p_13049.html

A cheaper alternative to replacing the VTC cam gear is to just replace it with an adjustable cam gear or simply the cam gear from an S13 SR20DET. You will also need the S13 intake cam gear bolt to do this. If you do take this path then you will notice a drop in power and torque in the bottom end. So it's best to keep the VTC cam gear.

 

[S15_Spec_R]

Is that solenoid a goldy/silvery colour 2 inch or so diagnally coming out of the drivers side cam cover near the cams?

I unplugged it and did a cold start and the noise was not there but like I said it doesnt always happen.

Can the car drive with the solenoid unplugged?

 

[mrpham]

You can drive it unplugged, just means your VTC is 'disabled'. You will noticed a decrease in torque and power in lower RPMs.

I had similar issues, initially the noise was a bit random and usually on cold starts. It would go away as soon as I start driving. But now it's getting worse and the rattle comes on more often even when warm. I unplugged my solenoid and it still was making the rattle noise. Next time when the engine is cold, just pop your bonnet open before you start the car, if it rattles then quickly unplug the solenoid.

You can see it in the photo below, just left and below the oil cap.
http://grip-industries.com/wp/wp-content/gallery/engine-sets/sr20det-s14.jpg

This is what it looks like:

 

[ali-d1936]

I dont mean to hijack your thread, but i was about to start a thread here bacause im having the same/similar problems, i posted on sxoc, and iv searched everywhere online everyone seems to think its either the solinoid or the cam gear, im still unsure what solinoid im disconnecting? and is it safe to do so? here is my post on sxoc,

o and thaks to mrpham! got his post on Sxoc informative advice :notworthy:

the more i read about it the last 2 days i realised that vvt rattle should only occour at startup. now when the car starts there is a rattle, after about 30 seconds its gone, the cars oil pressure at startup is 6 bar, after 10 minuites it drops to 3 bar and the second rattle starts, its like the vvt rattle only alot louder! the car idles continualy at 1000rpm, if i blip the revs the rattle goes, and if i stick it in gear release the clutch to biting point the rattle goes aswell, could this be the timeing tensioner? or is this all vvt rattle?
Any advice?
Alan


link to video http://www.youtube.com/watch?v=2F_0RM0Mz8U skip to 1:40 as the rattle starts there,