I have a 2000 blazer 4.3 and the engine has a light knock on start up first thing in the morning. [:-] Seems to go away after a minute or so and I don't hear it again until the next morning. Any idea's or is anyone else have a similar sound on start up? It only has 49K on it.

Thanks!

 

mine does the same thing but i have a 1992 4.3. i cant figure out what it is but i dont think that is a really big problem.

 

What State are you in? I live in Chicago and mine started doing it once it got cold. This is my first winter with my truck but i'm guessing it's normal.

 

im in seattle, washington.

 

Hey guys... Mine does the same thing... Is what I think it is , is oil pressure... Depending on the viscosity of the oil your using it dosent get pumped through the sytem fast enough causing a knock noise or lifter tapping... After a minute of idling on its own the pressure comes up and the noises go away..

Recommend that you let your truck idel on its own untill the presure comes up...



Bryan

 

ok my truck ocasionaly makes noise when i start it up in the morning and sometimes in the evenings sometimes it sounds like really bad valve clatter sometimes just like a lite engine knock from bad gas and usualy when it does this my oil pressure gauge will hit around 80 at idle and stay at 80 or climb higher when driving and i have waited till the truck is at normal opertating temp to drive still getting a knocking noise that will increase with acceleration and oil pressure needle will get buried


in case no one has noticed i have a lot of things wrong with my truck and am about ready to shoot it

 

By the sounds of it my idea isn't the problem.. Do you know if your getting lifter noise or more like a rod knock???

How many miles are on it... I have 170,000 on mine and it sounds like a sewing machine with the lifters.... Hope to motor in it in a few weeks... Your motor could be getting tired maybe too.




Bryan

 

i just passed 100,000 miles in feb. as far as noise goes i changes usually a hollow plastic kind of sound sometimes mettalic

 

Hmmmm just a stupid suggestion but I have had my fan blade hit the shroud on occasion and it sounds horrible. Just a suggestion... doughtful thats the problem but it could be ruled out...




Bryan

 

no i checked that out when i replaced the fan clutch