Mixed 5w30 with 0w20

[PontiacHO]

Originally Posted by zfasts03
Also the oil pumps rattle on startup as they "bounce" between high and low pressure on startup.

I believe their was a TSB on startup noise from the oil pump which was declared normal/acceptable.


Good to know. Anybody have access to those TSBs? This engine is noisy on startup. Quiet after warm.

 

[PimTac]

I just love the sound of a piston slapper in the morning

To paraphrase a famous movie quote.

 

[PontiacHO]

Originally Posted by CKN
I am on my third truck with the 5.3s. They can create a little noise on startup.

Its not broken.......


Yes. Had another 5.3 before this one and same thing. Just noticed it more lately. My ears ring so bad I can't hear it thunder some days. Probably was having a good day and noticed the noise. I can thank myself for no ear protection with air tools, target shooting, chainsaws, weed eaters, blowers, and doing some crew stuff with weekend dirt track buddies.

 

[DGXR]

I moved from 5w30 to 10w30 and that "cured" a lifter tick on cold start in the 1995 Corvette.

 

[PontiacHO]

It's always worth trying.

 

[OilUzer]

Originally Posted by DGXR
I moved from 5w30 to 10w30 and that "cured" a lifter tick on cold start in the 1995 Corvette.


Could it be that your 10W30 was more dino and less syn?

 

[bbhero]

Could have been the case ^^^^^^^^

Nothing wrong with experimenting to see what could help.

 

[zfasts03]

Not piston slap. Oil pump chatter for 1/2 second.

As per GM

Oil Pump Cold Start Rrrrp or Rasp
The oil pump design has changed from a gerotor gear-type pump to a two-speed vane type pump for fuel economy reasons. At temperatures at or below 32 degrees F or when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drainback. Upon startup the owner or technician may hear a short Rrrrp or Rasp coming from the front of the engine. It is most often heard during a remote start. There is nothing wrong with the oil pump or oil system. No repairs should be attempted for this condition.

Link:

https://www.tomorrowstechnician.com/gm-tech-tip-new-engine-noise-during-cold-start-up/

 

[oldhp]

Well 3 cylinders won't get as good mileage as the other 5..........

 

[PontiacHO]

Originally Posted by zfasts03
Not piston slap. Oil pump chatter for 1/2 second.

As per GM

Oil Pump Cold Start Rrrrp or Rasp
The oil pump design has changed from a gerotor gear-type pump to a two-speed vane type pump for fuel economy reasons. At temperatures at or below 32 degrees F or when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drainback. Upon startup the owner or technician may hear a short Rrrrp or Rasp coming from the front of the engine. It is most often heard during a remote start. There is nothing wrong with the oil pump or oil system. No repairs should be attempted for this condition.

Link:

https://www.tomorrowstechnician.com/gm-tech-tip-new-engine-noise-during-cold-start-up/


Very helpful info. Thanks for posting this. This is what I'm hearing.