Making engine run quieter/smoother, ideas?

[Z2TT]

VS Ecotec Making engine run quieter/smoother, ideas?

Hey Guys,

After being on here for a while and reading the issues people have i have a bit of an idea,
I have a VS Wagon, 330,000km. I had always thought these motors sound like this,
but my mate took me for a drive in his VT at 230,000km, it was so smooth, could barely hear the motor,
just humming, even on kickdown and 5000-6000rpm smooth as can be like a Lexus.

Mine, It starts, runs and drives, Bit shaky on idle, can feel it on
the steering wheel, slight misfire at times, I've done plugs, leads.
cleaned the throttle body, has a new fuel pump.

Would a brand new set of coils help out? or do these only give a very bad
misfire / no starting when they give up?

engine sounds quite noisy and as revs raise
engine begins to make a roaring noise especially above 3000rpm, drove another VS that was similar but not as bad. Have read that it could be the timing chain? I have replaced all the pulleys/bearings at the
front of motor.

Had a broken exhaust, I brought what was supposedly a stock exhaust from an exhaust shop,
it was "Super Cat" brand but fit up like stock. Louder than I expected thought for stock it would be near silent.

Any ideas on some good mufflers to replace the ones I got with for a stock like silent sound.

Cheers.

 

[Jxfwsf]

330,000 km's..... pull the engine out and rebuild it. Get the rods, pistons and crank balanced, it'll be better than new.

 

[Z2TT]

330,000 km's..... pull the engine out and rebuild it. Get the rods, pistons and crank balanced, it'll be better than new.

Cheers yeah I was thinking short of a rebuild what are some good tips as I've been in a few other ones close to 300k's that run real smooth.

Could it be the later (VT) engines were just better ballanced from factory or were built differently internally a bit?

Cheers.

 

[James39]

Mine would have close to that or even more and it runs smooth at idle and on the freeway you hardly notice the motor running. The only loud part is the exhaust as it has pace makers and is missing the resonator.
Was running a bit rough at idle when I first got this VS.
Since then I have replaced the inlet manifold gaskets serviced the fuel injectors, cleaned the IAC valve, cleaned the MAF,, replaced the air and fuel filters, replaced leads and spark plugs, replaced DFI and coil packs, engine oil, replaced the filter and trans fluid in the gearbox.

 

[Jxfwsf]

usual full service then (although it seems you have done this), timing chain if it's never been done could be stretched, harmonic balancer condition, fuel filter, fuel pump, injectors, fuel pressure reg, o2 sensors, bent push rod, balance shaft bearing......... needs to be diagnosed properly before blindly replacing bits, if there's no error codes then it could be something like i've mentioned.... running rough as you described can be caused by a lot of different unrelated things.

 

[VK SL 3800]

Buy some dynamat and go crazy, help reduce engine noise a great deal.

 

[Z2TT]

I'll be doing the Inlet manifold gasket soon as it leaks oil, so I guess that may seal up some hidden air leaks???
Might get the injectors cleaned while that's being done and change the fuel reg if it needs doing, is there anyway to test the fuel reg if it's in good nick?

Would old timing chain also decrease performance? As in alter timing?
Chain has never been done as far as the service records show.

How would I know if the harmonic balance is bad? I can't see any visual signs of damage or disintegration.

Cheers.

 

[Jxfwsf]

Would old timing chain also decrease performance? As in alter timing?
Chain has never been done as far as the service records show.

How would I know if the harmonic balance is bad? I can't see any visual signs of damage or disintegration.

Cheers.

fuel reg would be tested by checking the fuel pressure to make sure it changes correctly when the vacuum in the manifold does.

if the chain is stretched it'll retard the cam timing, which will decrease performance depending how far out it is..... (if it's the factory link chain that's never had attention then it could be causing issues, best bet is to get a decent roller chain replacement if you find it's part of the problem.

harmonic balancer, if it looks good and doesn't wobble excessively or make horrid noises when the engine is running then it's a fair bet it's ok.

if you're pulling the manifold off and willing to remove the timing cover to check the timing chain make sure you check the balance shaft front bearing while you're there for excessive end float.

 

[Z2TT]

Thanks jzw

Where can a roller chain and tensioner be bought from? In what ways is it better then the factory style chain?
Or is it ok to just go a factory Holden chain and tensioner?

Would the Gregories manual have information and instructions on checking the the balance shaft bearing for excessive end float?
What needs replacing if this is the cause or does something need to be machined?
Or is it simply just the bearing that needs replacing?
and could this be the cause of noises?
Any special tools needed to replace bearing?

When I'm doing the inlet manifold gasket, at this stage is it pretty easy to get the front timing cover off?

Can fuel pressure reg be the cause of engine requiring longer cranking to start?

 

[Jxfwsf]

Thanks jzw

Where can a roller chain and tensioner be bought from? In what ways is it better then the factory style chain?
Or is it ok to just go a factory Holden chain and tensioner?

Would the Gregories manual have information and instructions on checking the the balance shaft bearing for excessive end float?
What needs replacing if this is the cause or does something need to be machined?
Or is it simply just the bearing that needs replacing?
and could this be the cause of noises?
Any special tools needed to replace bearing?

When I'm doing the inlet manifold gasket, at this stage is it pretty easy to get the front timing cover off?

Can fuel pressure reg be the cause of engine requiring longer cranking to start?

The crow cams (cs6vs) is a roller chain, rollmaster also make them and more brands, like the chain used on a push bike it uses a rolling bush to contact the teeth on the sprockets and doesn't wear as fast as the factory chain. Roller chain - Wikipedia, the free encyclopedia another bonus with the crow set is you can advance/retard the cam timing in 2 degree increments or set it to stock, this changes the power band of the engine slightly.

A link chain as pictured below, is cheaper to make, uses layers of "links" shaped to meet the sprockets and is more likely to wear faster on the peaks that meet the sprocket teeth and more prone to stretching. (can't find a worn one must've binned them)


The factory style is ok to use again as a replacement, if on a budget this style of timing chain is cheaper, i've used a couple of crow sets over the years and
i'd use them again. Tensioners i've found ebay to have them for about $25 or supercheap for much the same, other stores i've priced them at are usually dearer.

yes the gregories has the info about checking balance shaft end float, requires a dial gauge but in my experience ones that make noise you can feel the shaft move back n forth, it's caused by the ball roller bearing at the front, no special tools required but a rattle gun comes in handy to buzz the bolt out of the shaft that holds the bearing in place. It can cause one of the common v6 rattle. Some people disable the balance shaft by removing the small drive gear but you're aiming for a smother running engine so i'd go about replacing the bearing instead if it's worn.

Probably the easiest time to have a look as you'll have alot of things unbolted and removed to access the inlet manifold gaskets.

Yes fuel pressure reg can cause delays in starting if it is failing/failed.