mitsuatb

iTrader: (6)

There are two timming belt idlers have you replaced the one on the P/S side?

The Techline Case in my post should be available from mitsu dealer.

In my case the noise went away when belt wore in.

Inspect old belt for wear on one edge.

Hard to say where the T/B is on the pulleys in a running engine. So check for rubber residue if it is rubbing it will build up somewhere.

The front lip of the oil pan to the aluminum front cover has shorter bolts 2 or 3 of them. Long typical bolts at that location might hit the belt.

If you are running a Fluidamper crank balancer ( Or other brands) it will rub on the plastic lower timing cover. I had to cut the lip down flat. The OEM damper has a cut out on the back that clears the lip.

Mitsuatb

krys88

Yes every single component is brand new. I just put together the whole engine. New timing belt/idler/tensioners the whole arm etc. I don't see any rubber residue and engine made already 500miles. I am also using Fluidampr and I had to cut out the lip from the timing cover. I will continue to drive and see if the noise goes away or if its get worse. Adjustment the tension for timing belt did not change anything. I try to loosen up the timing belt to the point that tensioner was extending the rod more than it should (by the mitsu manual rod should extend 3.8-4.5mm) and noise was the same so I re done tension the way it should be and I will drive it for now. The most weird is that this whining noise starting only after I drive it for around 20 min so only after engine is fully warmed up. Like the timing belt gets warm and making a little sound. It is evo 9 timing belt.

krys88

Guys I have an update as this might help someone in the future. Ok so the whining noise is from the timing belt but the tensioner is set correctly. What I did I installed on this engine very stiff valve springs (125lbs seat pressure) as my plan was to run 50+psi boost. What the problem is the valve springs are so stiff that when car is running auto tensioner is extending making t belt to tight. Even if I set the pulley tensioner too loose and I rotate the engine the auto tensioner will extend to the point that t belt is too tight because stiff valve springs giving a lot of force. I am wondering if evo 8 t belt would fix the whining because is not kevlar like evo 9 belt is. Or I will need to change the valve springs to little softer probably in 100lbs seat pressure area. Also too tight belt is not good for oil pump so it is making me nervous a little. No wonder I never had this issue previously because I was always using softer springs on past builds, non of them was as extreme as this one.

mitsuatb

iTrader: (6)

I don't think you are correct at all with your conclusions. The tensioner operates on the slack side of the belt. So valve spring tension will no change the tension on the slack side. Rubbing on the crank trigger is how the belt makes noise. Look for rubber residue on it. The belt will wear on its edge and noise will stop.

ViciousLSD

iTrader: (2)

youre probably sensitive to noise like me. but honestly I had maximum lifter noise for years but after I fixed it whatever whine that is left is music

krys88

No, there is absolutely no rubbing anywhere, and no wear to the belt on the edge. I did a little test on engine that I have in my shop with oem valve springs. I set the tensioner so the pin can be moved freely, and I rotate the engine. After couple minutes grenade pin can be inserted easily the way it should be. Then I installed gsc conical valve springs to this engine with 125lbs seat pressure, and I set tensioner to the exactly same position so pin was moving freely, and I rotate the engine. While rotating the engine I had to use more strength to rotate it and while rotating it I have notice that auto tensioner rod extended way more and belt got stiffer that I would not be able to insert pin back to the tensioner. So I did loosen it with pulley tensioner to the point that belt was very loose and I rotate engine again and auto tensioner extended even more and made belt stiff again. I and pretty sure valve springs are doing it because crankshaft need more strength to rotate the camshaft. You can even see that belt try to bend when I rotate it with very stiff valve springs and auto tensioner is doing its job to take the slack out of the belt. In my opinion 125lbs seat pressure is too much. I will try evo 8 timing belt first before I go with softer valve springs. I could be wrong but that's my opinion

krys88

I am very sensitive to the noises but you can hear this whining like crazy. Something like I have a supercharger. And now I am 100% sure it is t belt. I will try evo 8 belt because is not kevlar and if that will not help I will install softer valve springs. What valve spring do you guys use for high hp builds?

ViciousLSD

iTrader: (2)

my car has GSC valve springs, but I'm only <500hp. I also have their racing balance shaft which should be good for the oil pump

krys88

I was always using gsc beehive 5041 to all previous builds 500-750whp. They are around 100lbs seat pressure, but on this engine I used Gsc conical springs 125lbs seat pressure as I was aiming for 900-950whp. Do you guys always use evo 9 timing belt or evo 8 belt? I know 9 belt is kevlar it might whine when is too tight.

mitsuatb

iTrader: (6)

I run the gates blue racing belt with the blue balancer belt. I had a whine and after 10k or so it went away.

What you see with a static engine is not what is happening when it is running.

Clean the crank trigger and then use a black sharpie to color in the ears. The system is magnetic so will not change operation.

The lightest touch will make the most noise. If it touches at all it will remove the sharpie marks.

The adjuster is supposed to extend as needed. It is a hydraulic damped spring. The initial set position is only that. It will move over time.

I say send it.

krys88

I will definitely try sharpie. I will also try evo 8 belt just to see if whining is gone. Evo 9 is kevlar but it should not whine anyway. I will post with update. Thanks

Andyzulul

I have the same problem and i’ve been chasing this noise for like 2 summers now, changed all pulleys and belts 2 years ago, first time around the belt was definitely too tight and the whining noise was very loud, I’ve readjusted the tension many times since, gradually loosening it everytime until it was much quieter and I been driving it since (the noise did not get quieter) last week I decided to readjust the tension again, but I set it to the “proper” tension, the whining noise was super loud again… Gonna try just loosening it this week and see if it gets quieter, but I am totally stumped at this point, Evo 9 belt as well, looking to see if your Evo 8 belt would solve it.

krys88

A little update. So I installed evo 8 belt and it was a little more quiet but not by a lot. So if the noise was similar I decided to put back evo 9 belt because it is better especially for this high hp engine . I set tension in correct position and whining noise was there but at that point I was tired and frustrated chasing that noise so I decided to drive it the way it is. I made over 1k miles now on this belt and fresh engine and noise is a little more quiet but still there. It is not as loud as it was in the first hours of driving but still a little bit. What I notice is that if you set it too loose it will also whine more as well as too tight.The more I was adjusting it the more whine I had so I set it correctly and I left it there and I will not touch it for now. I can only hear that whining when I drive steady at around 2700rpms and all windows are closed.

Andyzulul

Update, I have discovered the problem... after dealing with this noise for 2 years now...
So I was adjusting the tension again last weekend, since I was fully determinded to eliminate that noise, I just kept adjusting the tension and starting the car in order to see if the noise gets any better, and I have managed to eliminate the whining noise all together, perhaps not for the reason you'd expect though. I've alway used all the Evo timing belt service Youtube videos to get me through the process, but I believe the problem is that in 99% of the videos, they are doing the tension incorrectly...? I was only loosening the tension and starting the car until the noise was significantly quieted down, which didn't make sense to me because I felt like I was basically setting the tension way below spec and that can't be good, but I never questioned the video tutorials because most of them says that they're just following the service manual and there's no further updates on whether there's a whine or not, but of course I don't know if those people have the whine problems, maybe nobody notices the sound or did everyone actually made this mistake?
And nobody will question it either because everyone believes that if the Grenade Pin on the auto tensioner slides in and out, then it is tensioned properly, but when the belt is on so tight like that, the auto tensioner isn't going to move. because there's no slack in the belt, it isn't going to tension it further, so is it really still tensioned "correctly"? Last time when I tensioned again like in the Youtube tutorials, the belt was so tight that my Idle was completely messed up, sitting around 1200rpm at idle and rev hangs ALOT, all these problems were gone after properly tensioning, right now the evo drives perfectly, no belt whine and idle perfectly too, I am extremely happy,
I attached some picture with explanations,

In the service manual, when they tension the pulley, they're pulling 31 inch-pound around 90 degree to the tensioner pulley bolt, which lands the 2 hole nearly fully facing downwards, but in all the Youtube videos I checked, they are doing it straight down, which lands the 2 hole usually between the tensioner arm bolt, in the service manual it basically is just enough tension to cut the slack, rather than really "Tightening".

In all the video tutorials I checked, they're all tensioned the wrong way, the last picture was the only one where it actually looks like how it is in the service manual.
Unless there's some people out there with no belt whine with the "wrong" tension, I believe this is the reason for the belt whine, it's just way too tight.

ViciousLSD

iTrader: (2)

Several people have reported that their cam gears skipped a number of teeth, so I'm not sure if its worth the risk. recently my intake cam gear skipped 3 teeth just trying to start the car with the #4 coil not getting power.
It probably depends on the belt condition/brand. I've had the Gates belt for several t-belt jobs and I haven't heard it whine