Oldsmobile/Buick Repair: feelin unarmed, cutlass supreme, dianostics

Question
QUESTION: I own a broken 95 cutlass supreme coupe sl dohc 3.4 liter and am  having a hard time finding a cure. Basiclly broke down with abnormaly worn broken timing belt. I took it to a gm dealer and they repaired timing belt and idler pulley[they said it basicly  was obvoious) to the tune of $1100.00! after, they discovered a noise that was not there before.  they suggested the car was running very well but the noise was strange and  was coming from the timing chain compartment [debree and other matter behind idler)  dianostics and labor came too a ffurther $800.00. they didnt find anything there but the noise persisted. remember that is is supposed to be a G.M. DEALERSHIP they told me it would be in my best instrest to aquire someone cheaper to further diagnose and repair. putting my parts into a box and reminding us that they would not like to go any further in this matter closing the door. So a quick rundown The timing belt broke whilst driving was then repaired along with 1 iddler pulley, once the repair was complete the car was started with a "noise" present. The investigations lead to the opening and closing of the timing chain compartment to no avail. I am then advised that next step is to open either the top end OR  yes OR the bottem end of the car to find the source of this "noise" The car is now with a relative who has listened to it whilst running  with a scope(parts still in a box) the sound seems to come from the beyond the camshaft. Now the research will be done as to next move..... what avenue do you suggest i take???

ANSWER: Hi
Could you please try to describe the noise, to the best of ability.
A whirring noise?
A hiss(ing)?
A knock?
A tap?
Does it follow engine speed or does it seem faster?
or does it stay constant?
Can you "feel" it if you place your hand on the enfine?
Can you feel it sitting in the car?
Thanks
Pawl


---------- FOLLOW-UP ----------

QUESTION: well it appears to be a tapping sound.the car starts and runs at proper idle.the sound seems to follow engine speed.cant feel noise while sitting in car.

ANSWER: Hi Arnie, sorry for the LONG delay, wife been ill.
Could yo please tell me did the timing belt actually BREAK or STRIP out?
If so, was the vehicle running?
I ask because this is an interference engine, meaning thwe valves CAN interfere with the piston movement.
Will await your responce.
Pawl

---------- FOLLOW-UP ----------

QUESTION: Hi Pawl! No worries about the delay car has been broken since may haha. So the belt actually broke whilst driving at highway speed......however we were advised by the GMC dealership that this is not an interference engine as that was our first question. The dealership assured us that the engine was not such and the belt could be replace with no other damage(providing it ran well in the first place is what they kept saying)The car was in perfect running order pre belt break. Is this engine an interference engine for certain??? if so I believe that we need to be going back to the shotty advice from the dealership?? where would we be able to locate the documentation or specs to show that our engine is the interference model? this would help greatly and aslo any advice at this point you may have regarding the "noise"
thankyou Arnie

Answer
Hi Arnie
PK I found out the 3.4 DOHC is considered a "freewheeling" engine, meaning the possibility of valve to piston damage in the event of a timing belt failure may be minimal or very unlikely. (Previous post was my bad, I am sorry)
That being said I also found out from a VERY VERY good Old timer fellow auto tech who said if the belt was installed "improperly", which is VERY, VERY easy to do ("Even at a dealership"), it will cause a "Clicking" noise from the cam shafts/lifters.
That is what I found out for you today.
Please follow back post.
Pawl
PS
All "quotes" are his EXACT words.