Need some guidance

rrh13441

Member
Mar 24, 2022
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0
6
I have a fully deleted 2012 GMC LML that just had the head gaskets replaced and did the CP3 upgrade. I had a static coolant leak got the head gaskets replaced and when I picked up my truck the coolant level, when cold was setting even with line in the picture. All is running well no issues at all except the coolant level is still going down about a cup or so, checking when cold. When the truck is warm the coolant is all the way to the top looks.

Any suggestions on what to do? as I said runs great but sometime notice a bit of white smoke when I start it but was told that’s normal.


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Ron Nielson

Active member
Oct 11, 2009
760
141
43
Berryton, KS
Take a look at the attachment. These newer tanks are different, just different. Not sure I understand them.
 

Attachments

  • Coolant procedure LML .pdf
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,654
5,800
113
Phoenix Az
I have a fully deleted 2012 GMC LML that just had the head gaskets replaced and did the CP3 upgrade. I had a static coolant leak got the head gaskets replaced and when I picked up my truck the coolant level, when cold was setting even with line in the picture. All is running well no issues at all except the coolant level is still going down about a cup or so, checking when cold. When the truck is warm the coolant is all the way to the top looks.

Any suggestions on what to do? as I said runs great but sometime notice a bit of white smoke when I start it but was told that’s normal.


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Sounds correct to me. Should be at the top or “max” line when hot.
 

jlawles2

Well-known member
Jan 28, 2010
1,057
39
48
Danbury, TX
As long as the coolant is returning to the same level when cold and you are not having to add fluid past possibly the first or second time you get it up to temps on the road for more than just long enough to get it to temp, all is fine.

If it's one of the newer style coolant tanks with the left hand threaded cap on the top and a cap on the side that you basically cannot access, the fluid level is supposed to be between the lines and will push the fluid to the lower tank when it expands when hot. When it cools it will pull excess fluid from the lower tank.

On my 18 I could never get the upper tank to be where it was supposed to be. After the tank replacement I ended up with the upper tank full and when I het 25F temps it would tell me the coolant level was low, so I had to fill it to the top again. That's the only time I added fluid after the tank replacement.

All engines have a range they like to maintain. Learn that range and if it gets outside of that then you get worried or if you have to keep adding to maintain that level.
 

rrh13441

Member
Mar 24, 2022
45
0
6
I got a new tank and it only has one mark (see picture) near the top of the tank. My question is, is this a low level when the truck is at operating temperature? If so, do I just not worry about the level when cold as long as the level stays above the min mark when at operating temperature?
6f71591c3fe99c10bd4d13ded06f5d83.jpg



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jlawles2

Well-known member
Jan 28, 2010
1,057
39
48
Danbury, TX
Since you can only open the cap when hot, fill it to that line and let it rip. There is an internal overflow that will purge any excess into a separate tank and draw back when it's cold.

Make note of the level of fluid when hot and cold, and if it falls below those (after a few cycles of filling it this time) then start looking for issues.