VY Ecotech engine to VT Auto transmission issue

[YellowSticker]

Are the flywheels on these 3.8L ecotec engines balanced to the torque converters?

My 1999 VT 3.8L Ecotec engine **** itself and I replaced it with an Ecotech from a 2003 VY.

Both engines say LN3 on the respective VIN identification plate.

I removed my engine at the gearbox housing, so those bolts and the 3 flywheel (?? flexplate?) bolts are all I dealt with when I put the new VY engine in.

I noticed the inspection covers are different, I had to use the VY ones but they still covered my VT gearbox just fine.

The guy I got the engine off asked if I aligned the torque converter up and I said I didn't think so. The starter motor makes a clunk when it starts (that's how he could tell).

He said something about 2 weights that need to be at 180 deg of each other. He said to remove the 3 bolts on the flywheel through the inspection cover, rotate the position and see if it clunks on start up.

He said if the starter motor clunks STILL after all 3 positions on the flywheel have been tried - i will have to remove the torque converter off my old motor and do the same thing.

I read a lot about marking the flywheel and **** to keep balance when reinstalling engine but because I was doing an engine transplant (ie. Not using the exact same motor), my repair manual doesn't say jack **** about what to do in that case. So I just bolted it on.

I have read somewhere now that the counter weights that balance the VY engine to the VY gearbox may not be present, or are different, to the VT engine and gearbox.

I'm guessing that means I will need to remove the torque converter from my VT engine and install it onto the VY engine to use my gearbox? OR I will have to use the VY gearbox that came with the engine. Which is a whole new set of issues because I like my VT auto gearbox.

Does anyone know if that is the case? The VY gearbox says 3HFD. No idea what my VT one says.

Other than the clunk the starter motor makes when I start the car, is there another way to check the engine and gearbox are balanced?

 

[_R_J_K_]

Just use the VT gearbox, it'll be fine. You don't really balance a gearbox. The engines are pretty much exactly the same.

I'd be more inclined to try and see if there's a way you can reposition the starter or if there's any slack in how it mounts, if the flex plate is off centre then it should only do it on one side of the flex plate and there'd be some kind of noticeable vibration when you're driving (particularly if the flex plate is unbalanced or out of phase).

Is there a vibration when it drives?

Anybody know if it's possible to put a flex plate on backwards?

 

[Lex]

Did you use the vy engine loom? The loom that was on the vy engine when you got it.

 

[Not_An_Abba_Fan]

The flexplate is balanced, the torque converter is balanced, they are never balanced together. If the torque converter stayed on the transmission then it is already lined up and sitting in the pump. If you used the flexplate and torque converter off the VY engine, then did you make sure the torque converter seated properly in the transmission when you put the engine in?

 

[YellowSticker]

I used my loom the engine didn't come with one.

I have never dealt with an auto before so I am a bit unsure of flexplates, torque converter and **** so attached is pic of what I took out of my car.

I never took the flexplate thing OFF either engine, I just bolted it to the gearbox that's the only time I touched it.

Did the flexplate need to be fitted back on a particular way to those 3 bolt holes on that gearbox in the picture I guess is what I'm asking?

I just lined the first hole up that I saw through the flexplate to attach it back to the gearbox when I had my neighbour turn the crank.

I'm wondering if the gearbox wheel has a weight on it (hidden behind it maybe) like the flexplate does, because a reliable source said it has to be at 180 degrees to the flexplate weight or the gearbox won't be balanced hence my engine behaving like its misfiring (its shaking like something is off) .

2 mechanics have helped me and both say it looks like its misfiring. Tech 2 scan had a vacuum leak which was fixed by 1 of them but that same guy asked about the orientation to the gearbox and that I might need to use my old VT torque converter if none of the 3 holes on the VY engine flexplate stop the start motor clunk/engine shaking.

I wonder why he would say something so specific.

Now I say shaking, but he picked it up from the starter motor clunking when it begins to turn the engine over. I'm assuming the shaking is now related.

I'm pretty sure everything is seated fine because everything pulled up fine and got bolted up and the car started and does infact drive quite fine. But ignoring this stuff can lead to catastrophe, if there is infact an issue here.

Maybe I used my VT starter motor? I don't know. But I was told ignoring this will result in a fucked starter motor, eventually. At a minimum. At worst, engine **** itself and 6k down the drain I can't keep investing in this thing.

Also engine mounts i used were from the VY as well. Great condition. My existing ones were fucked out hard.

 

[Lex]

Hi
Not sure but the way l have read this post is confusing. That pic that you have posted is of a transmission with a torque converter on it.
Is that vt trans & torque converter? If so the tc hasn't been removed the trans.

Good that you used the vt engine loom. From what l've read, vx - vy wont fill the vt.

If you using the vy starter motor its possible that the vy solinoid is cactus.
Try putting the vt one in. Either way just try swapping them out.

 

[Not_An_Abba_Fan]

I'd try swapping starter motors first. VN-VY are all the same.

 

[YellowSticker]

Ok so thats the TORQUE CONVERTER in the gearbox.

That is the VT gearbox and obviously the VT torque converter because I thought it was just the gearbox and the torque converter was a part of the engine block.

So I have gone and bolted the VY engine to the VT torque converter and gearbox. I didnt check the location of counter weights or anything. I just bolted them together without checking anything.

So I need to remove the inspection cover, take the bolts out and find out the location of this weight to line it up.

There can only be 3 possible ways and I have already done 1 way I guess.

 

[YellowSticker]

Guys my neighbour said it would be the dumbest ******* thing he has heard in his life for a torque converter to have to be balanced to a flexplate. Because if you send a torque converter to be fixed they rebuild it and balance it on its own.

So in theory it shouldnt matter - its just that the repair manual says to mark the relationship of flywheel to torque converter bolts to keep balance and I told the other mechanic I used the VY torque converter (I told him that not knowing what a torque converter was).

Neighbour reckons the starter motor noise is just pre ignition knock. Maybe need a higher octane fuel if the 3.8L ecotech runs at a higher than "normal" compression or some ****.

 

[YellowSticker]

This is my VT ecotech engine flywheel and the VY ecotech engine flywheel.

Should I have changed flywheels if I was going to keep the VT gearbox? Or absolutely not because its balanced to the engine?