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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: bowdown916 on April 29, 2011, 12:24:15 AM

Title: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on April 29, 2011, 12:24:15 AM
Sup guys, i have this sound on the engine,its hard to describe,but it makes it when truck its park on idle or when driving, it kinda sounds like if it had something stuck and its trying to unplug it, engine wont die or stall on me when driving, it just makes that noise, it just start making it couple days ago,havent done anything other then putting some trans fluid... i wish i had a better idea of what im talking bout! :( ... ill see if i can find a better description of that noise...
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: slammed79 on April 29, 2011, 01:40:51 AM
Maybe a stuck lifter. Did you ever get your timing situation handled?
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: ccz145a on April 29, 2011, 07:39:21 AM
Most engine noises can be describe as a:
tick
knock
whistle
screech
or rattle
Do any of those temrs describe your situation?
Title: Re: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on April 30, 2011, 08:59:19 AM
Umm. Kinda like knock. It kinda sounds like it might stall ..
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 01, 2011, 01:51:21 AM
ok,it sounds more like a rattle now..this just start doing it few days ago, also the other thing that cant describe lol...
so the rattle its only when accelerating,not sure what made this , i changed the oil,trans fluid...
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: 1979C20 on May 01, 2011, 02:41:53 AM
You may have turned the distributor when putting tranny fluid in. check your timing.
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: Blazin on May 01, 2011, 08:05:07 AM
Is the starter sounding different when you start it? Could be the flex plate is giving it up around the crank flange? Kinda a common thing.
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: big bear on May 01, 2011, 09:45:50 AM
i was having similar noises once in my truck with a 305 out of a 86 trans am. ...instead of taking my time and thinking, i jumped the gun.  i talked too 100 people and your going to get 100 opinions.  so most common answer was a lifter issue.   so i dove right in.  put new cam and lifters in. then before reassembling,i heard it could be my timing chain slapping. now, let me tell you . haha  i pulled the timing chain cover off and wow.  there were slap marks everywhere , and it was so sloppy and loose, as soon as i grabbed it, it fell right out to the floor.  lucky i checked that out.  i put in a basic, double roller setup.  and lastly i heard it could be the flexplate,  i checked that out, it was ok.  now i cant complain, i took a gamble. i yanked that motor out of the trans am, and it went right into my truck.  all i did was changed valve cover gaskets and water pump gaskets.  and i beat the crap out of it.  so when it started clattering and clacking, i wasnt all too mad. plus i paid 100 bux for the motor.  after i did all that work to it, it sounded so much better.  sorry to hijack on your thread man.  i just wanted to share a similar story maybe you can relate too.  good luck
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 01, 2011, 09:54:12 PM
thats cool big bear...
well today my n my bro were moving the distributor little bit and it seens like it help it ,no more of those bad noises,but still seens like the engine dont have enough power,maybe it still needs more adjustment...

also, if the dist. its electric, i would have 4 wires coming out from the dist. and connecting somewhere to the hardness right?

if it wasnt electric,then that wire from the dist. would connect to the dist. cap coil right?
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 01, 2011, 10:49:49 PM
wheres the flex plate located?
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 01, 2011, 10:51:56 PM
flex plate its the fly wheel right?...

theres a small leak right where the converter and fly wheel its i think,but its hard to take off the that bottom cover between the oil pan and trans pan..
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: Grim 82 on May 01, 2011, 11:20:14 PM
flex plate its the fly wheel right?...
An automatic transmission uses a flexplate that is bolted to the crankshaft, and the torque convertor is bolted to the flexplate. A manual transmission uses a flywheel, which has a thick friction surface for the clutch. If you have an auto, you have a flexplate, if you have a manual, you have a flywheel.

The leak that you describe could be a rear main seal, or possibly the back of the intake or the valve covers.
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: Blazin on May 01, 2011, 11:21:03 PM
Flex plate is used with and automatic transmission, Flywheel with a standard trans.
Not sure what you mean by electric distributor?  It should be an HEI with the coil in the top of the cap. There should be  one pink wire plugged into the drivers side of the cap. If it has a tach then there might be a wire plugged into the cap right next to the pink one. If it is controlled by the ECM it will have a 4 wire harness that comes out the bottom back corner of the dist. just below the bottom of the cap and plugs into a wire harness that passes through a grommet right near there into the cab to the ECM.
Title: Re: Re: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 02, 2011, 12:09:16 AM
Flex plate is used with and automatic transmission, Flywheel with a standard trans.
Not sure what you mean by electric distributor?  It should be an HEI with the coil in the top of the cap. There should be  one pink wire plugged into the drivers side of the cap. If it has a tach then there might be a wire plugged into the cap right next to the pink one. If it is controlled by the ECM it will have a 4 wire harness that comes out the bottom back corner of the dist. just below the bottom of the cap and plugs into a wire harness that passes through a grommet right near there into the cab to the ECM.

Ill take some pics tomorrow of those wires.
Title: Re: Re: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 02, 2011, 12:11:55 AM
flex plate its the fly wheel right?...
An automatic transmission uses a flexplate that is bolted to the crankshaft, and the torque convertor is bolted to the flexplate. A manual transmission uses a flywheel, which has a thick friction surface for the clutch. If you have an auto, you have a flexplate, if you have a manual, you have a flywheel.

The leak that you describe could be a rear main seal, or possibly the back of the intake or the valve covers.

What will be the easies way to get to the flexplate? I been trying to get that cover off to take a better look but can't get it off without maybe removing trans pan and maybe oil filter...
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: Blazin on May 02, 2011, 05:51:57 AM
Should only have to remove the oil filter to take that cover off.
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 02, 2011, 08:56:59 PM
(http://i366.photobucket.com/albums/oo109/tiburone9162003/2011-04-23_20-03-50_369.jpg)

(http://i366.photobucket.com/albums/oo109/tiburone9162003/2011-05-02_13-49-15_992.jpg)

(http://i366.photobucket.com/albums/oo109/tiburone9162003/2011-05-02_13-49-04_751.jpg)

(http://i366.photobucket.com/albums/oo109/tiburone9162003/2011-05-02_13-48-52_925.jpg)
Title: Re: 305 engine 1986 scottsdale bad sound
Post by: bowdown916 on May 02, 2011, 09:11:44 PM
so that plug its from the dist. and connects to the wiring on the wall and im thinking it goes inside to the comp.

i havent checked yet,but i guess the connectors that connect to the dis. cap comes from the wiring hardness?