Jump to content
SAU Community

Adjustable Cam Gear Problem?

Drakey

By Drakey,
in Engines & Forced Induction

 Share

Recommended Posts

Drakey Collaborator

Drakey

Posted
Posted

Hi All,

Have a quick question for you.

I bought a skyline that has a few mods, like cooler, r34 turbo, all the usual and also has adjustable cam gears.

Now a couple of weeks since i bought the car i heard a squeaking from the cam gear cover, sounded almost like a pully.

Well i got the car serviced and about 2days later the noise went away so i didnt worry about it anymore.

But now my car seems to lack alot of power from what it used to have. It used to start breaking traction in 1st gear and when i changed to second the car would step out sideways. Now its the mildest churp. So i dont think its just me getting used the the car. The car also seems to have a flat spot now just above 4K and certainly does not pull how a car running properly should.

My question is could of something came lose or something gone out of adjustment with the cam gears, its all i can think of?

Any help peeps?

Link to comment
https://www.sau.com.au/forums/topic/209892-adjustable-cam-gear-problem/
Share on other sites
**RB2530** Proficient

**RB2530**

Posted
Posted

Mate I would get it checked out...If it is a cam pulley adjustment that has come loose there is a risk that it will shear or wear the adjustment bolts. That may then lead to loss of drive on the cam shaft and that is very very bad...Piston colliding with valve territory...equivalent to broken timing belt...Dont want to scare you but also dont want to see you stuff your engine...

You can easily check the cam pulley adjustment bolts on the exhaust cam by just removing the crank angle sensor but if you are not confident in doing this, get someone else to do it...You need to make sure it goes back on properly...

Drakey Collaborator

Drakey

Posted
  • Author
Posted

Awesome thanks rb

Ok Ill check it out to see.

Another question. Im not sure how adjustable cam gears work, well i have an idea. But if they are now out of whack will I have to take it to someone to get them set in the right place?

And need to be tuned up again?

**RB2530** Proficient

**RB2530**

Posted
Posted

Unfortunately if it turns out they have moved, to get them perfect again, it will mean dyno work...

But you always can just have them set at zero (no dyno work required) and your car will be fine...Adjustable cam gears change the power curve characteristics of your engine...You can tune them to give more high end power but you lose mid range and vice versa...The gains you get will depend a lot on other engine mods as well..If you do a search you will find out heaps more info on this...

Main thing at the moment is to make sure they are not loose and jumping around everywhere which is a nightmare waiting to happen....Better to have them set at zero and tight rather than bent valves and a big bill....

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
Unfortunately if it turns out they have moved, to get them perfect again, it will mean dyno work...

But you always can just have them set at zero (no dyno work required) and your car will be fine...Adjustable cam gears change the power curve characteristics of your engine...You can tune them to give more high end power but you lose mid range and vice versa...The gains you get will depend a lot on other engine mods as well..If you do a search you will find out heaps more info on this...

Main thing at the moment is to make sure they are not loose and jumping around everywhere which is a nightmare waiting to happen....Better to have them set at zero and tight rather than bent valves and a big bill....

well not really fine, it would still require a tune potentially as the gears are no longer where they were

so the car wouldn't drive the same on the tune that's allowing for it

BAMR33 Mentor

BAMR33

Posted
Posted

Cam gears don't squeak when they're lose, they rattle and sound like your engine is going to blow up. I should know because I forgot to tighten my ex cam once. Probably just a belt squealing same area much more probable noise.

Tyre spin from 1st to 2nd? what a useless gauge of performance. Could be anything that has changed... road surface, air temp, slope, tyre pressure, road speed, clutch usage, driver control.

Have you even asked what the service involved? normally a service is just oil, filter/s change and a check up on everything thing else.

**RB2530** Proficient

**RB2530**

Posted
Posted
well not really fine, it would still require a tune potentially as the gears are no longer where they were

so the car wouldn't drive the same on the tune that's allowing for it

Depends on how radical the tune actually is...'a few mods to me means std ECU or aftermarket ECU with close to stock tune'...Good thing about Nissan platform is it uses afm over map sensor (as you know) and therefore any changes to the basic airflow characteristics of engine (due to cam adjusment) are acounted for by ECU...

And when I was thinking 'fine' I was thinking safe engine operation vs piston colliding into valve...

**RB2530** Proficient

**RB2530**

Posted
Posted

I just remembered about a car I saw with a similar problem..What had happened was the guy fitted the CAS back to his car without the rubber grommet....The rubber grommet actually has brass spacers in it where the CAS bolts go through. If the grommet (and therefore spacers) are not used the end of the CAS shaft will bottom out in the end of the cam shaft...this puts a big load on the CAS bearing and it will stuff the bearing and CAS in no time..

Also as previosly mentioned check all of your belts are tight...Loose belts will squeak especially when they are cold...To diagnose sqeaking belts, start the car and spray the pulleys with something called belt dressing...You can get it from Repco...If it is the belts, as soon as you spray them they go quiet...Well they do for me anyway...

Drakey Collaborator

Drakey

Posted
  • Author
Posted
Cam gears don't squeak when they're lose, they rattle and sound like your engine is going to blow up. I should know because I forgot to tighten my ex cam once. Probably just a belt squealing same area much more probable noise.

Tyre spin from 1st to 2nd? what a useless gauge of performance. Could be anything that has changed... road surface, air temp, slope, tyre pressure, road speed, clutch usage, driver control.

Have you even asked what the service involved? normally a service is just oil, filter/s change and a check up on everything thing else.

Yeh i understand that and i know plenty of things can change and that is a terrible way to gauge performance. But the ones i did notice is major lack of power anything from 4K and above and i had trouble passing a au falcon that normally wouldnt have any worries.

I just remembered about a car I saw with a similar problem..What had happened was the guy fitted the CAS back to his car without the rubber grommet....The rubber grommet actually has brass spacers in it where the CAS bolts go through. If the grommet (and therefore spacers) are not used the end of the CAS shaft will bottom out in the end of the cam shaft...this puts a big load on the CAS bearing and it will stuff the bearing and CAS in no time..

Also as previosly mentioned check all of your belts are tight...Loose belts will squeak especially when they are cold...To diagnose sqeaking belts, start the car and spray the pulleys with something called belt dressing...You can get it from Repco...If it is the belts, as soon as you spray them they go quiet...Well they do for me anyway...

Yeh i used to work at a car servicing place and i took it back to them. i was there when it was service and it was usual filter + oil and general check over.

your idler bearing could be on the way out. Often these aren't changed when people diy thier cam belts at 100k.

Makes sense, but would it stop squeaking?

Ok so i have booked it in to get tuned. im not sure why it isnt making the power it used to but im taking it to get it tuned by the last people that tuned the car. Hopefully its something simple. but i did notice the car's fuel economy has gone down aswell all at the same time.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Duncan's V37.......race car?

      By MBS206 · Posted

      Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • RP1421
      S15 Spec R

      By RP1421 · Posted

      As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...