4g61t.org

Just put a VR4 (4G63T) engine in a 89 Cyborg 4WD (Mirage with 4WD) and the engine is realy rough and noisy especially on boost and high revs. You can hear it at idle but not as load. Its loader when driving the car.

Any clues???

My mechanic can't pic it. The timing is correct we have checked it twice.
decieded to remove the balance shaft belt to see if it fixed it but its still there.

The car goes fast so it doesn't seem to be effecting power.

Any info would be great.

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Steve

GO THE BORG!!!!!!
_____________________________________________________________________
Cyborg 4WD (C73A) - VR4 engine – ET 13.3@103m/h 60'–1.82
http://www.cardomain.com/id/vr4cyborg

it seems the balancer shaft driven by the oil pump is off by one turn.

http://www.vfaq.com/mods/timingbelt-1G.html
by the way
I WANT A CAR LIKE YOUR'S!

he said that they removed them already.

No new ideas from me though..

Rough and noisy...? Could be a shot bearing somewhere, maybe even the tranny or clutch.

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Got rabies?

You say it does not effect preformance? Might be a bad throw out bearing rattling and making noise. Did you install a new throw out bearing when you had the tranny out?

So are the shafts still in or what. Please clarify... If they are IN and the engine is VIBRATING, then your balance shaft sprockets are out of phase. If you are hearing a loud NOISE that get louder with acceleration
AND your shafts are still in, chances are the REAR BALANCE SHAFT BEARING might be going bad.
This sound is denoted by a "rrrrrrrrrrrr" sound when you either accelerate or increase your rpms'.

TRY this though, rev the car with your foot on the clutch, if your car is making the sound when you foot is on the clutch and NOT naking it when the clutch is out then you have an issue with your drivetrain [ie: possible T/O bearing] and not your engine rotating assembly.
:

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Geoff

89 Colt Turbo
92 GVR4 254/1000 Kensington Gray

When we first heard the noise we had both balance shafts connected. We then disconnected the front one by just pulling the belt off. Still made the noise.

The noise is more of a resonance than vibration and occurs while in and out of gears.(still there with cluch in)
The sound could be described as a "rrrrrrrrrrrrrrr" sound.

_________________
Steve

GO THE BORG!!!!!!
_____________________________________________________________________
Cyborg 4WD (C73A) - VR4 engine – ET 13.3@103m/h 60'–1.82
http://www.cardomain.com/id/vr4cyborg

Thanks for the response.

Pull off the intake pipe between your mass air flow meter and your turbo.
Check the turbo for excessive play by trying to wiggle compressor wheel,
a "little" bit of side to side play is acceptable.

In and out play is NOT acceptable


Let me know

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Geoff

89 Colt Turbo
92 GVR4 254/1000 Kensington Gray

What engine mounts are you using?

When I took out my solid polyurethane mount and went back to a stock mount it was bliss!

The solid mounts transmitted so much vibration into the car and were very noisy! When I picked up the car for the first time after having it done I thought something was wrong with the timing belt (timing belt had just been done at the mechanics)

Mike

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1991 CB Lancer GSR (5dr Hatchback) with 4g61t conversion - 132kw/180hp @ the front wheels. SOLD!

Check out my website: www.members.optusnet.com.au/~onnzo

Member #31

Switch, I totoally agree with you on that one.

I have poly mounts on my GVR4, and the balance shafts were removed.
I'm seriously thinking about re-installing stock motor mounts.


Hows the weather over there. You guys are going thru Autumn or Winter right?

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Geoff

89 Colt Turbo
92 GVR4 254/1000 Kensington Gray

that was my idea to switch. i told him about the trouble you had. i thought that maybe the top mount they had to modifiey was not done right and causing one of the other mounts to make noise or something. that or this idea about the balance shalfs might be something to. thank god for the 61t!! no balence shalf.

Thanks guys for all the suggestions.

But all the engine mounts are still stock with no solid mounts the cam belt one was just modified so that the engine sat level.

And the engine doesn't seem to vibrate its more of a resonance.

As for the turbo, I checked it before it went in and there was no play in and out, so that rules that out.

Someone said earlier that the oil pump balance shaft could be 360' out because the shaft spins twice as per one revolution of the engine. Correct me if i'm wrong but it shouldn't matter if it is 360' out because then it is the same. Spining the shaft a full 360' will just bring it back to the same position. Maybe i'm just confused.

Anyway. I'll keep looking.

_________________
Steve

GO THE BORG!!!!!!
_____________________________________________________________________
Cyborg 4WD (C73A) - VR4 engine – ET 13.3@103m/h 60'–1.82
http://www.cardomain.com/id/vr4cyborg

Hey Geoff, Its winter here but we are still getting 35oC days in melbourne!!!

If your's is a daily driver I'd say swap them back to stock! It is so much more comfortable and makes for a nicer drive...

Sorry Steve but I can't think of any other suggestions for the time being!

Mike

_________________
1991 CB Lancer GSR (5dr Hatchback) with 4g61t conversion - 132kw/180hp @ the front wheels. SOLD!

Check out my website: www.members.optusnet.com.au/~onnzo

Member #31

There is a specific timing for the balanceshafts if they are out of timing your car will make a stange noise. ELIMINATE THE BALANCSHAFTS. I had a JDM motor and the balanceshaft bearings failed causing the oil pump to lock up snapped my timing belt, and bent all my valves in the head. So take it from me get rid of the balanceshafts. You will have minimal vibration that you will feel after 3500rpms then it will go away. Other then that the car revs faster and you gain another 8-10HP.

the oil pump gear rotates the balance shaft in ratio of 1 oil pump turn for .5 turn of the balance shaft. So if youre pump gear is off by 360 degree, your balance shaft is off by half a turn