Loose harmonic balancer

[lt70turbo]

Have any oneone had this happen balancer bolt loose, will it cause enough vibration to damage main bearings resulting in low oil psi, all four mains are beat-up rod bearings have some wear signs but look to be ok cam bearings look ok too, checked oil pump and it is tight no slack engine ran good for about 5 months then oil psi started to drop more each time i drove the car got to the point were the oil light would light-up pulled engine and found balancer was loose.

 

[williambavila]

i would bet that you had another problem by the looks of those bearings. looks like crap in the oil.

 

[williambavila]

i ran a loose balancer for about 3 months and have not seen a drop in oil pressure. i replaced the balancer and still have 80lbs at cruise and 25 at idle. I would bet that is from lack of changing oil and using the wrong type of oil. i would have the line bore checked as well as all rods for sizing. also try mobile one and a good filter with a magnet on it as well as the pan

 

[lt70turbo]

williambavila that is the only issue i could find loose balancer again car ran fine no knock or rattle oil psi just started to drop off to the point were the oil light would come on that lead to pulling the engine.

 

[lt70turbo]

Used castrol 10W 30 with STP oil was always changed only had about 1k on it, line bore was good when i assembled the motor with girdle torqed you could spin crank with hand and get 2 to 2.5 turns out of it thats a good straight bore no binding. when i say loose balancer meaning the bolt was loose to the point it would move back and forth about 2"

 

[mikestertwo]

STP

 

[DIAZ 87]

I had my harmonic balancer bolt loosen up and ended up breaking the balancer which cause my timing to go out of wack for 1/2 of the summer of 08

 

[Dr.drivability]

I had my harmonic balancer bolt loosen up and ended up breaking the balancer which cause my timing to go out of wack for 1/2 of the summer of 08

Same thing happened to me except I bent all 6 intake valves

 

[Chuck Leeper]

We have..

i would bet that you had another problem by the looks of those bearings. looks like crap in the oil.

a WINNER! X2
Cut the filter open... You'll likely find it's loaded w/ trash.
For only 5 months on a rebuild, I'd say there's ALOT of varnish and some serious looking patterns on the cyl walls, too.
Could have been, the engine was dirty when assembled???

 

[Grumpy]

pic #2 bearing has taken a beating.. you def have something else goin on like others have said.

 

[84BuickGNYorkPA]

Oil pressure was dropping because the bearings where going to junk and allowed the oil to run out with no back pressure/resistance from close tolerance between bearing and crank. I would try a different machine shop this time.... how long untill you changed the oil on the fresh engine build?
I would not recomend STP on a fresh build, it won't let/help the rings seat to the cylinder wall, causing smoke and blow bye.
On my fresh motor a yr ago with roller set-up oil/filter came out after 100 miles(and it was full of slivers/debris in filter cut open and paper element pulled apart ). Then 500 miles later again oil/filter change(clean and blood pressure came back down). After 2000 miles went to Mobil 1.
I also had a loose balancer bolt on the fresh build, only damage was that the crank sensor would lose it's signal and car would die.... the internal problems are from something else.... like Chuck Leeper said maybe there was some dirt in the assembly or you waited to long before the 1st oil change.

Chuck

 

[Mike Licht]

who assembled the motor?

 

[williambavila]

I was raised in machine shops and a loose balancer would never cause that type of damage.Having a fresh rebuild would tell me a few things..1 the machine shop was probably a great one for sbc/sbf but not the turbo buick motors they require tighter clearances 2 the machine shop did not clean all galleys and ports in the block.3 whoever put the motor together did not clean and check clearances. I would recomend using a rebuilder on the site.I have a bunch of years experience with motors but would not attempt to bore & hone & line bore one of these before i did a ton of research.. just use someone that knows about the motors.. ONLY use mobile 1 synthetic.....and use king bearings this is a must and trust me you will thank me in the long run....

 

[lt70turbo]

Mike i did the engine myself local machine shop did the machine work i made sure that it was clean maybe i missed something. did a 30min. run changed the oil and filter and again at about 200 miles after that i only drove the car on weekends, now be steel crank/rods/dimond or go stroker, dont realy now what the issue is but back to the drawing board all ideas or direction will be greatly appreciated thanks.

 

[Mike Licht]

So what sort of procedure did you use to clean the bloack crank and rods before assembly? What were the bearing clearances when you measured tham at assembly time?
Mike

 

[Grumpy]

now be steel crank/rods/dimond or go stroker, dont realy now what the issue is but back to the drawing board all ideas or direction will be greatly appreciated thanks.

better figure out what happened BEFORE ya just start throwing parts at it:redface:

 

[84BuickGNYorkPA]

Your timing chain set wasn't super tight was it? Somehow you got excessive wear, dirt in oil, dirt in assembly, clearances to tight.....

Chuck

 

[Chuck Leeper]

If this rebuild was due to an engine failure, did you replace the oil cooler in the rad???

 

[lt70turbo]

Mike i cleaned the block/crank with high psi hotwater brake parts cleaner and compressed air, rod and main 2ths.

84Buick GN timing chain was not super tight did have a little slack (double roller)

Chuck no oil cooler using a turbo saver with filter behind headlight

Grumpy you are correct need to find out what happened i will keep looking to see if there is something i missed.

 

[TurboDave]

What brand mains??? I've seen that same delamination on the mains in another thread on this board.