balance shaft timing

[bronn518]

Hi, I have a 97 Achieva with a 2.4L that had spun all the rod bearings and a couple mains. I figured that engine was junk so I took a 96 2.4L out of a Grand Am that also had very minor bearing issues. I put a reground crank into it and put it back together and into the car. Got it running and it seems to run fine but it has a strange sound to it. Its not a knock or anything but it has a deep vibration sound coming from it. I think it may be related to the balance shaft timing because when i was setting the balance shaft timing, the instructions werent very clear as to how the balance shafts were to be positioned in relation to the crank. When i set it, i had the flats spots facing toward the oil pan and the crank on tdc. I am wondering how the timing is suppose to look and if it is possible to take oil pan off while engine is in the car. Thanks

[xeroinfinity]

Did you mic the new bearings before puting it back into the car?

The harmonic balancer could be bad causing the vibrations.
But thier could be other issues causing the knock.

Have you check the knock retard sensor?
If this is bad it could also cause some knock.

I think the oil pan will come off without removing the engine, but some of the trans to engine bracets will have to come off. Not a very fun job

Hope that helps!

[bronn518]

Thanks for the reply, the bearings came with the reground crank so they were matched for how much the crank was ground so i didnt bother to mic them. Its not actually a knocking sound that i am hearing. It is a deep vibration sound. I used the harmonic balancer that was originally in the car and it wasnt causing any vibrations before, just the engine knocked very hard. I was wondering that i maybe got the balance shaft timing off by 180 degrees.

[xeroinfinity]

Even though the bearings came with the crank, I always double check

But as you suspect it very well could be off time.
You did torq the crank bolt to spec?

keep me posted on what you find.

[gmack221]

to answer your question about the oil pan removal, yes it can be done in the car, you will need to drop the passanger side cradle (frame under motor, 6 or so bolts), remove the trans bracket (passanger side), remove the coolant tube that runs under the pan, and need to pull a stud on the drivers side (goes to the trans 7mm socket I believe, & don't lose the spacer). I only told you the difficult parts of the removal ... the rest should explain its self & as long as you leave the passanger side motor mount on the fender you shouldn't have to support the motor. I'm trying to remember which way the flats went on the balance shafts when I did mine, I know I had to ask my GM mechanic buddy ... maybe call a GM shop to find out before tearing into it.

[bronn518]

Well, I was able to look at another engine and compare the timing of that. It turns out i was 180 degrees off. I managed take the pan off and get it switched. What a pain it was though, but at least now it runs like a watch. Thanks for the replys.