Are there any GM Techs out there?

Billy Nees · 12-02-2020, 07:31 PM

Alright, I am pretty sure that I've got it. With the thermostat closed, coolant goes through the heater core and into the rear of the block and is circulated through the block and head by the water pump. When the thermostat opens, water goes into the LOWER radiator hose AND through the block and head. It goes through the radiator and into the UPPER radiator hose where it is circulated through the block and head until the thermostat closes . Clear as mud....

jamie2370 · 12-02-2020, 08:27 PM

Billy, sometimes I think even GM doesn't know how it works lol. I have followed some of their diagnostic trouble trees for certain trouble codes that say , Step 1... replace this part Step 2... does code reset Step 3.... if yes replace this part Step 4...Does code reset, if yes, refer to Step 1

Tom Meyer · 12-02-2020, 11:42 PM

We have always put a hose loop so that coolant flows as the engineers designed it. It is almost easier to remove the exhaust manifold to get to the thermostat. We have put are temp gauge fitting in the flat spot by the hose outlets. There is a bolt holding the tube from the thermostat to the water pump, push the tube into the pump there is a o ring on it the twist and remove. Tom

Billy Nees · 12-03-2020, 08:16 AM

Tom, where did you put the "hose loop"?

Tom Meyer · 12-03-2020, 09:28 PM

We just looped the heater hoses using a u shaped formed hose with one 3/4 the other end is 5/8. We have been running these motors for the last 8 years, 4 IMCA national dirt championships and 4 UPs. Been to tech [top 4] about 600 times, one guy told me I brought to much stock / super stock mentality to the class. Tom

Billy Nees · 12-05-2020, 05:28 PM

Quote:

Originally Posted by Billy Nees

Alright, I am pretty sure that I've got it. With the thermostat closed, coolant goes through the heater core and into the rear of the block and is circulated through the block and head by the water pump. When the thermostat opens, water goes into the LOWER radiator hose AND through the block and head. It goes through the radiator and into the UPPER radiator hose where it is circulated through the block and head until the thermostat closes . Clear as mud....

OK, I just got finished getting "verbally abused" by my engineer buddy about the laws of physics. So I'm going to start from scratch about how this thing flows.
The coolant goes FROM the rear of the block and through the heater core. It then flows over the hot side of the thermostat and into the water pump where it circulates through the block and head. When the coolant flowing through the heater core and over the hot side of the thermostat gets hot enough, it opens the thermostat letting cold coolant from the radiator flow past the COLD side of the thermostat into the water pump( the thermostat really IS backwards!). Suction from the pump pulling cold coolant from the radiator (lower hose) lets hot coolant go from the top of the head (upper hose) into the radiator...
This is as clear as mud!

ss3011 · 12-05-2020, 08:23 PM

GM has standards for heater performance, so heating up coolant quickly so the heater provides heat to the passengers is a high priority . Included in that is they don't want to shock the block and heads with cold coolant ,so the special thermostat was developed . I believe its similar to the older LT1 style thermostat .

12-02-2020, 07:31 PM	#1
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,485 Likes: 3,587 Liked 7,682 Times in 1,730 Posts	Re: Are there any GM Techs out there? Alright, I am pretty sure that I've got it. With the thermostat closed, coolant goes through the heater core and into the rear of the block and is circulated through the block and head by the water pump. When the thermostat opens, water goes into the LOWER radiator hose AND through the block and head. It goes through the radiator and into the UPPER radiator hose where it is circulated through the block and head until the thermostat closes . Clear as mud.... __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

12-02-2020, 08:27 PM	#2
jamie2370 Member Join Date: Dec 2014 Location: Perry, GA Posts: 331 Likes: 11 Liked 239 Times in 90 Posts	Re: Are there any GM Techs out there? Billy, sometimes I think even GM doesn't know how it works lol. I have followed some of their diagnostic trouble trees for certain trouble codes that say , Step 1... replace this part Step 2... does code reset Step 3.... if yes replace this part Step 4...Does code reset, if yes, refer to Step 1

12-02-2020, 11:42 PM	#3
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 936 Likes: 77 Liked 351 Times in 120 Posts	Re: Are there any GM Techs out there? We have always put a hose loop so that coolant flows as the engineers designed it. It is almost easier to remove the exhaust manifold to get to the thermostat. We have put are temp gauge fitting in the flat spot by the hose outlets. There is a bolt holding the tube from the thermostat to the water pump, push the tube into the pump there is a o ring on it the twist and remove. Tom __________________ Tom Meyer 5240 SS Stock ???

12-03-2020, 08:16 AM	#4
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,485 Likes: 3,587 Liked 7,682 Times in 1,730 Posts	Re: Are there any GM Techs out there? Tom, where did you put the "hose loop"? __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

12-03-2020, 09:28 PM	#5
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 936 Likes: 77 Liked 351 Times in 120 Posts	Re: Are there any GM Techs out there? We just looped the heater hoses using a u shaped formed hose with one 3/4 the other end is 5/8. We have been running these motors for the last 8 years, 4 IMCA national dirt championships and 4 UPs. Been to tech [top 4] about 600 times, one guy told me I brought to much stock / super stock mentality to the class. Tom __________________ Tom Meyer 5240 SS Stock ???

12-05-2020, 08:23 PM	#7
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 909 Likes: 70 Liked 239 Times in 114 Posts	Re: Are there any GM Techs out there? GM has standards for heater performance, so heating up coolant quickly so the heater provides heat to the passengers is a high priority . Included in that is they don't want to shock the block and heads with cold coolant ,so the special thermostat was developed . I believe its similar to the older LT1 style thermostat .