07 Chevy Silverado 8.1 welding truck

[Rob_Roy]

Originally Posted By: c502cid
Although I've heard of 8.1's using oil, mine both might go through a quart, quart and a half between 6000-8000 mile OCI's.


Nothing wrong with those numbers!

I seem to remember some guys on dieselplace in the gasser forum recommending a 180F thermostat for the 8.1 to reduce underhood and oil temperatures, I will see if I can search out the thread.

 

[c502cid]

Originally Posted By: Rob_Roy
Originally Posted By: c502cid
Although I've heard of 8.1's using oil, mine both might go through a quart, quart and a half between 6000-8000 mile OCI's.


Nothing wrong with those numbers!

I seem to remember some guys on dieselplace in the gasser forum recommending a 180F thermostat for the 8.1 to reduce underhood and oil temperatures, I will see if I can search out the thread.


I do this to all big blocks, not just the 8.1's. However on the 8.1 I do it to keep the computer from taking out timing, not so much to reduce temps.

 

[tightwad]

Originally Posted By: eljefino
First thing to check would be the sending unit, ie put a good mechanical gauge on it. Agree with the oil analysis in case there's been a long term intake air leak letting unfiltered grit grind away inside the engine.

Does that truck have an oil temp gauge? Maybe add one?


Yes, check the sender. I've seen and heard of problems with Chevy sending units.

 

[JimPghPA]

Originally Posted By: dhellman12
Sounds like the consensus from the group is change the oil & filter, and drop the valvoline conventional in favor or Rotella or some other HDEO.

Changing from a 10w30 to either 5w40 or 10w40 will most likely provide the higher oil pressure he wants to see. In his application, are there any down sides to switching to a higher vis oil?


Thicker oils usually cause a small drop in MPGs.

If you run too thick of an oil in the winter like a mono weight 40 or 50 you could cause the motor to break a connecting rod or damage the crank. Stay with the multi-grades with a low first number like Rotella T6 5W-40 in the winter and you should never have a problem.

Something like a 20W-50 would be risky below 15 Fahrenheit.

 

[c502cid]

Originally Posted By: JimPghPA
Originally Posted By: dhellman12
Sounds like the consensus from the group is change the oil & filter, and drop the valvoline conventional in favor or Rotella or some other HDEO.

Changing from a 10w30 to either 5w40 or 10w40 will most likely provide the higher oil pressure he wants to see. In his application, are there any down sides to switching to a higher vis oil?


Thicker oils usually cause a small drop in MPGs.

If you run too thick of an oil in the winter like a mono weight 40 or 50 you could cause the motor to break a connecting rod or damage the crank. Stay with the multi-grades with a low first number like Rotella T6 5W-40 in the winter and you should never have a problem.

Something like a 20W-50 would be risky below 15 Fahrenheit.



Hee hee hee, you mentioned gas mileage in the same thread as 8.1!

 

[dave1251]

 

[expat]

Just thinking, If the truck is running 1800 rpm at 55mph, the engine is not working that hard!

If he was really pulling, he would be in a lower gear. Then I would expect higher temps, oil loss etc.