Twin turbo ls overheating issue

spongbob

Greasemonkey
Oct 1, 2022
156
91
28
Puffing out of cover ? Motor could need break in oil like chevron or kendle" ?or worse broke ring/s could a need a steel moly ring...( hastings)...high heat output :someone will say cats plugged I would think valves tight or leaking .either way if you don't find it you will have to go over everything even re Tighten head bolts/ studs...of coarse back flush the radiator.some motors can shed debri that shuts the tubes off im not knowing yours is...you have got to have really good sealing valves and valve settings/ train whatever" to run the coolest Temps period ,it's not going to be late timing...good luck
 
Last edited:
  • Like
Reactions: 1 user

81cutlass

Comic Book Super Hero
Feb 16, 2009
4,667
13,646
113
Western MN
Some people will bypass the thermostat by leaving it out or plug the heater ports and on an LS they are required to route the coolant flow into the places that need cooling, so if you have a Tstat and the heater ports are looped, that's a good first check.

Do you have hot water going into the rad? If you put a temp probe into the rad through the cap, is it 180F+?

Is the water coming out of the rad hot? Or is it cool?


If the water is going in hot and out hot, it's an airflow issue.
If it's going in cold, it's internal block or flow issue
If the water is going in hot and out cold but it's still overheating, it's probably a volume issue

Stick a temp probe in the rad and touch the return hose on the rad and figure out where the heat is going (or staying)
 
  • Like
Reactions: 4 users

carnutjw

G-Body Guru
Supporting Member
Sep 17, 2017
636
1,523
93
I'm ignorant of LS and turbo issues, but if you are running twin turbos (intercooled I assume), that's a lot of heat under hood. Do you have any hood vents, cowl hood, etc. to allow more airflow through the engine bay? The intercooler could obviously be another airflow obstacle as well.
 
  • Like
Reactions: 2 users

melloelky

Comic Book Super Hero
Oct 22, 2017
4,216
9,742
113
mass
creeping up at idle? from what temp to what temp?are the fans triggered or set on kill all the time?
 
  • Like
Reactions: 2 users

64nailhead

Goat Herder
Dec 1, 2014
5,759
1
12,356
113
Upstate NY
Some questions : ‘heating up’ - what does that mean EXACTLY? For reference, 215 is not hot and 225 is starting to get warm and 235 is close to hot. How much run time on this? Has it been driven at highway speeds for more than 3 minutes? What is the timing, AFR and rpm at idle? What ECU?
 
  • Like
Reactions: 1 users

mclellan83

Comic Book Super Hero
Jun 27, 2017
4,399
9,917
113
Pgh, PA
Some questions : ‘heating up’ - what does that mean EXACTLY? For reference, 215 is not hot and 225 is starting to get warm and 235 is close to hot. How much run time on this? Has it been driven at highway speeds for more than 3 minutes? What is the timing, AFR and rpm at idle? What ECU?

JK
 
  • Haha
Reactions: 1 users

johnnunez29

Master Mechanic
May 9, 2022
271
62
28
Some questions : ‘heating up’ - what does that mean EXACTLY? For reference, 215 is not hot and 225 is starting to get warm and 235 is close to hot. How much run time on this? Has it been driven at highway speeds for more than 3 minutes? What is the timing, AFR and rpm at idle? W
Some questions : ‘heating up’ - what does that mean EXACTLY? For reference, 215 is not hot and 225 is starting to get warm and 235 is close to hot. How much run time on this? Has it been driven at highway speeds for more than 3 minutes? What is the timing, AFR and rpm at idle? What ECU?

no highway speeds. cars not THAT road worthy. needs a complete alignment. ecu i terminator xmax. i havent gotten past 225, i shut it off at that point.
 

johnnunez29

Master Mechanic
May 9, 2022
271
62
28
I'm ignorant of LS and turbo issues, but if you are running twin turbos (intercooled I assume), that's a lot of heat under hood. Do you have any hood vents, cowl hood, etc. to allow more airflow through the engine bay? The intercooler could obviously be another airflow obstacle as well.
2" cowl
 

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor