Engine noise please help!!!

[Grey87T]

Hi,Im new to the site,and I have owned a 87 GN back in 1996 which I left stock.My neighbor bought my car I have now,1987 T brand new,the car has 84,xxx original miles on it,and is stock.The car was sitting an entire year without being ran or even turned over.When we first started it up,which it only took one try,it had what sounded like a lifter noise,and once I changed the oil it quieted down a bit.I did the (spring cleaning) on it and the car runs 100% better,it runs great!!!I have put about 200 miles on it now,the noise is still there and its not the injector tick or cam sensor either.It seems quiet when started and gets louder when up to temperature,with the windows up driving in the car you can hear it,with them down its hard to hear,so you gauge how loud it is.Now I took the car to a very highly recommended Buick mechanic that knows these cars very well.When I described to him over the phone the problem he thought a cam sensor,or possible wiped cam lobe when he heard it in person,he told me that it was rod or piston slap,and that some of these cars had a problem with it from the factory,something with the off set crank,and that as the bearings wear over time it becomes louder.Did anyone ever hear of such a thing? I dont know much about these cars..PLEASE HELP!!!!

[Grey87T]

COME ON??? ANYONE HAVE A SUGGESTION??? I was wondering if these cars are known to have bottom end problems???? bearings etc. my other 87 GN had 90,000 on it without a problem

[Turbo2nr]

If a rod bearing was bad, it would sound scary bad! How about a loose exaust joint? Take off the valve covers and start engine. See anything funny? Oil? everything moving ok? What about metal in the oil? check it out. This is going to be hard to help you, without being there to hear it!

Scott H.

[Keller]

The car was sitting an entire year without being ran or even turned over.When we first started it up,which it only took one try,it had what sounded like a lifter noise,and once I changed the oil it quieted down a bit.

Let me make sure I got this right: This car sat for a year, and you just started it up with the same oil in it? No effort to get some circulated first?

Chances are the whole top end was completely dry. So the lifters might not have been pumped up. And some might still not be quite right. That is one particular area to look for a problem. 'Piston slap' was not a factory option. And many of these cars go a quarter- to a half-million miles or so with no major internal engine problems. Granted, they aren't raced and abused cars.

You may just have a lifter that is not fully pumped up, or got some dirt in it and can't. Your crank sensor may need adjustment; those can be very noisy. There are several other potential areas of noise. Very hard to spec a problem at a distance. With no oil pressure gauge, I'd advise another oil change and cut open the old filter to look for metal pieces. Also, adjust the crank sensor to avoid any noise there. Check torque converter bolts as well.

[Grey87T]

I know that its hard because you cant hear it,but any info is greatly appreciated...as for starting it up after sitting a year,it was not my car at that point and I had no say in the matter,I didnt like the fact it was started that way either.But the piston slap deal,that was suggested from someone else thats why I asked about it,I dont know what these motors are prone to.I also have a RS 69 Camaro with a BBC in it that runs 9.70's@140 on the motor,pump gas street legal car.So Im used to BBC'S and dont really know about these.Now the crank sensor can be noisey also? I was told to listen to the cam sensor,he said they can rattle when started but the noise should go away. Im just trying to learn about these cars.Thank you for the info.

[Keller]

Now the crank sensor can be noisey also? I was told to listen to the cam sensor,he said they can rattle when started but the noise should go away.

The crank sensor detects a shutter wheel with three 'windows'. If out of adjustment, the windows will strike the sensor as it rotates. It can sound like light rod knock or top end chatter. You can use slices or pop/soda bottles as feeler gagues to set. Look for it on the front of the motor, drivers side, mounted to a bracket off the front cover nestled against the balancer.

The cam sensor is basically a sensor that resides where the distributor was. Its up front in the front cover and on top, opposite the oil pump. Unless its shutter wheel has fallen off its base or its been spun around a large amount, it should not be a factor. But if its not set right, the car will not run.

This chart may help a bit http://www.gnttype.org/maint/sensors.html

Adjustment procedures here.

Also, the fuel pump should briefly run when the key is in the ignition position and the car is not started. It would be worth confirming this as well.