valve lifters clattering.dirty engine?

[Carguy80]

My ride is 92 firebird and engine makes this crazy rattle noise could be the lifters,i dont no.Anyway,when engine is cold,there is no rattle coming from the engine. But when i drive it about 5 minutes,it rattles but when engine is fully warmed,rattle is really quiet. when i let the car be in the garage like 15-30minutes,it rattles again but again,when engine is at the normal operating temperature, rattle is quiet. It is still there,but rattles very little. It seems that every time when i put new oils in,engine rattles like crazy,it sounds like that i have a diesel engine in my car, instead of 3.1 v6 gasoline engine.So,i have new oil in the engine,(10w30 conventional) and rattle sound is still there and the more i drive, like 3000 miles,rattle sound is really quiet.But i change my oils after every 3000 miles,and rattle sound is back again. It seems that i should put even thinner oil to make the rattle go away,but i dont want to put thinner than 10w30 in my 92 v6 engine. One time i went and i was driving about 120-140km/h about 1 hour,and when i stopped my car and i was listening to the engine,no rattle noise at all. So maybe there is a bit sludge or something in the engine? I have now 76 high performance conventional oil in the engine,and i was thinking to add 1 or 1/2 quart 76 10w30 super synthetic blend in to the engine,maybe it would clean the engine a bit? i just wonder is it wise thing to do? I would put maybe 4 quarts synthetic blend or fully synthetic oils in the engine,but i have small oil leak,and synthetic could make it to leak more.Any thoughts how i could clean my engine? They sell here these small bottles that says:"guarantee to stop valve clattering" should i try one of those "stop valve clattering" products? Thanks.

 

[m2200b]

If its all the time or not just at start up I'd quess more of a stretched cam chain as the lifters aren't usually a big deal on 3.1 other than there is a fair amount of moise anyway. The chains usually doesn't stretch until more like 200K. I'd try a 10-40 in the summer before I put anything in a little bottle in.Maybe that's why the previous owner used a 40W.

Can you narrow the noise down as lifters are closer to the top of the engine maifold and the piston slap is

 

[m2200b]

Try some intake cleaners - maybe you have some carbon cruding up the valve seating.

 

[m2200b]

You should arx this as well as do intake cleaners.

With valve noise your try thing - eg 5-30 and you try thicker 5-40 or 10-40 and see which is helping. If you have a dirty motor adding dino blend is at best like adding 1 qt of syn to 3 qts of dino and I wouldn't expect much cleaning
since you get only some at all syn or HDEO.

So far you have found that 5-30 and 10-30 don't help your lifter noise. The 10- 40 will also quiet piston slap but thyat tend to go away as the motor pistons and rings heat up and fill more space.

Most of those little bottles are just kerosene but I suppose if it says it has moly you'd get some help.

 

[CBDFrontier06]

Doesn't sound like lifters....all my OHV engines' lifters were loudest cold, at startup and gradually quieted down as they warmed up and got lubricated. Your circumstance does remind me of a timing chain issue my roommate had with his Cavalier...it was WAY below 100K and had the chain replaced due to excessive noise, which did come and go depending on the circumstances.

 

[BlazerLT]

tonttu,

Are you filling the engine with the exact amount of oil the manual suggests or are you going by the dipstick.

Overfilling the oil by even 1/2 to 1 quart can cause the crank to slap the oil which introduces air into the oil system and introduces air into the lifters which causes the clattering on GM engines.

My 4.3L which is a 5.7L minus two cylinders had this problem until I noticed that I was overfilling the oil by going to the full level on the dipstick which was close to 1 quart overfilling it.

 

[JohnnyG]

Regardless of what is causing the noise, unless it gets substantially worse, or can be linked directly to a mechanical failure, it will not harm your engine or shorten its life. Continue to go strictly by the owners manual for oil weight, type, API spec. and frequency of change and enjoy all of the benefits of GM engineering. You can try any and all of the additives that you wish, but I don't think they will make a bit of difference either way.

 

[BlazerLT]

Actually, a valve train clattering will wear it out faster than if it was properly supplied with lubrication.

Dry lifter clatter will wear the lifters out prematurly on any engine or make.

 

[Carguy80]

Originally posted by BlazerLT:
[QB] tonttu,

Are you filling the engine with the exact amount of oil the manual suggests or are you going by the dipstick.

Overfilling the oil by even 1/2 to 1 quart can cause the crank to slap the oil which introduces air into the oil system and introduces air into the lifters which causes the clattering on GM engines.

My 4.3L which is a 5.7L minus two cylinders had this problem until I noticed that I was overfilling the oil by going to the full level on the dipstick which was close to 1 quart overfilling it.

I have 4 quarts oil in the engine.it is the same amount that my 92 owners manual shows.I have also chilton 82-92 repair manual and that one shows 4,5 liters,but i put only 4 quarts because that is the amount that my original 92 owners manual shows.When i put 4 quarts in the engine, my dipstick shows full mark,or a bit lower.

 

[BlazerLT]

Ok, just making sure seeing overfilling can cause valvetrain chatter.

 

[Carguy80]

Originally posted by m2200b:
[QB] If its all the time or not just at start up I'd quess more of a stretched cam chain as the lifters aren't usually a big deal on 3.1 other than there is a fair amount of moise anyway. The chains usually doesn't stretch until more like 200K. I'd try a 10-40 in the summer before I put anything in a little bottle in.Maybe that's why the previous owner used a 40W.

Can you narrow the noise down as lifters are closer to the top of the engine maifold and the piston slap is


I have been used conventional 15w40,10w40,5w30 and now 10w30,and i have found out,that with 15w40 my engine clatters all the time from cold engine to hot,and after 2000-3000 miles clattering was really quiet.Same thing with 10w40,but when engine temperature was almost 100c.,clattering was quiet.With 5w30 and 10w30 it only clatters when engine is like half of the normal operating temperaure,but when it is at the normal temperature,clattering is really quiet.

I can hear the clatter easily,when i go and check tire pressure from my front tires.

 

[Carguy80]

Originally posted by BlazerLT:
[QB] Ok, just making sure seeing overfilling can cause valvetrain chatter.

You are right about that overfilling causes valvetrain clatter.I once put a bit too much oil in the engine,and it sounded like clatter was louder.Thats why i keep oil level just a bit lower than full mark.

 

[m2200b]

Have you listened to any other 3.1 GM? It is a noisey engine at idle and lower speeds.

 

[Hirev]

quote:

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Originally posted by m2200b:
Have you listened to any other 3.1 GM? It is a noisey engine at idle and lower speeds.

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Kind of what I was thinking when I read this.

 

[Carguy80]

Originally posted by m2200b:
[QB] Have you listened to any other 3.1 GM? It is a noisey engine at idle and lower speeds.

My friend has firebird too,with a 3.1 v6 engine.There is no clatter or piston slap or anything like that.Just smooth v6 sounds.