No water circulation after head gasket change
10-16-2015, 01:00 PM
#1
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
No water circulation after head gasket change I replaced a head gasket on a buddies 2006 Silverado 1500. Ordered a new water pump and thermostat as well. Heads were checked at the machine shop and milled flat.
I assembled the motor, filled antifreeze and fired it up. It ran good, temp started rising and stopped just above 210. Heating was fine and i went for a test ride for about 4 mls.
Everything fine as well. Temp a tad above 210. Back at the garage, parked the truck with the motor running then the temp started going up. Checked the hose to the radiator, no pressure, hand warm. Heater hoses hot, but could touch them.
The lower radiator hose was cold. Thermostat not open?
I removed the housing, checked thermostat in boiling water, OK.
Puzzeld everything together again, started, temps rising even more. NO temps in the heater hoses. Plain cold.
I had no time to check the water pump today. Belt is ok.
Something like this happend to someone before? Looks like the new GM water pump doesn't pump. Or are there other possibilities?
I assembled the motor, filled antifreeze and fired it up. It ran good, temp started rising and stopped just above 210. Heating was fine and i went for a test ride for about 4 mls.
Everything fine as well. Temp a tad above 210. Back at the garage, parked the truck with the motor running then the temp started going up. Checked the hose to the radiator, no pressure, hand warm. Heater hoses hot, but could touch them.
The lower radiator hose was cold. Thermostat not open?
I removed the housing, checked thermostat in boiling water, OK.
Puzzeld everything together again, started, temps rising even more. NO temps in the heater hoses. Plain cold.
I had no time to check the water pump today. Belt is ok.
Something like this happend to someone before? Looks like the new GM water pump doesn't pump. Or are there other possibilities?
10-16-2015, 01:46 PM
#3
12 Second Club
iTrader: (3)
Join Date: Apr 2004
Location: Grand Rapids, Michigan
Posts: 1,512
Likes: 0
Received 2 Likes
on
2 Posts
What he said. There's a passageway on the front of the block on each side that gets blocked if you put the gasket on backwards. The gaskets are usually marked "Front" and put on correctly on one side that is facing up (and obviously towards the front) and on the other side of the block that will face down (and towards the front). You just have to make sure that the front passageways can be seen through the gasket.
10-16-2015, 01:54 PM
#5
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
What he said. There's a passageway on the front of the block on each side that gets blocked if you put the gasket on backwards. The gaskets are usually marked "Front" and put on correctly on one side that is facing up (and obviously towards the front) and on the other side of the block that will face down (and towards the front). You just have to make sure that the front passageways can be seen through the gasket.
10-16-2015, 02:11 PM
#7
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
You say pull the right head. Whats with the stretch bolts? I have to replace them again or did someone successful reused them?
Trending Topics
10-16-2015, 02:19 PM
#8
As long as you had front facing the timing cover, your fine. But even then, as far as i am aware the heads would still have ports open to allow flow through the cylinder head. Not to mention the fact that with the way the hoses are routed on most LS engines you would get hot hoses on either side regardless what orientation the gaskets were. Sounds to me like you have a faulty water pump or a bad thermostat, so the first and easier of the two things is to run it without a thermostat. (side note, make sure your thermostat has a small 1/16 hole or bobble valve to allow for air bleeding through the tstat to prevent air pockets)
As you can see from the picture below, both sides of the gasket have large ports to allow water to flow through the cylinder head from the water manifold, the only thing that would be obstructed would be flow around the sleeves.
As you can see from the picture below, both sides of the gasket have large ports to allow water to flow through the cylinder head from the water manifold, the only thing that would be obstructed would be flow around the sleeves.
10-16-2015, 02:40 PM
#10
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
As long as you had front facing the timing cover, your fine. But even then, as far as i am aware the heads would still have ports open to allow flow through the cylinder head. Not to mention the fact that with the way the hoses are routed on most LS engines you would get hot hoses on either side regardless what orientation the gaskets were. Sounds to me like you have a faulty water pump or a bad thermostat, so the first and easier of the two things is to run it without a thermostat. (side note, make sure your thermostat has a small 1/16 hole or bobble valve to allow for air bleeding through the tstat to prevent air pockets)
As you can see from the picture below, both sides of the gasket have large ports to allow water to flow through the cylinder head from the water manifold, the only thing that would be obstructed would be flow around the sleeves.
As you can see from the picture below, both sides of the gasket have large ports to allow water to flow through the cylinder head from the water manifold, the only thing that would be obstructed would be flow around the sleeves.
But without flow through the heater the thermostat could not open.
I can check without thermostat but with the internal water bypass in the water pump there will be no flow through the heater core. The radiator should work with no thermostat.
Unfortunately the water pump has the pressed back so i can't check if there is something wrong internal.
10-16-2015, 02:46 PM
#12
Hmmm because ONLY after I filled the coolant through the upper rad hose did it become available for the thermostat to do its job and circulate coolant. From just the rad/overflow filled, you won't have any luck unless you were being sarcastic lol I don't know
10-16-2015, 03:02 PM
#13
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
The expansion tank is T-ed in the return hose coming from the heater core. The thermostat has bypass holes between the water pump in and out passage to the heater core so i can't see why the thermostat should have no water to work with.
I would agree if you said the water pump has to be purged over the upper radiator hose t owork properly. Is this what you're talking about?
I would agree if you said the water pump has to be purged over the upper radiator hose t owork properly. Is this what you're talking about?
10-16-2015, 03:14 PM
#14
I haven't tried the heater hose route but I know what you mean now as far as the routing. However it doesn't make sense that the stat isn't opening despite being tested like the stuff I went through but it only indicates that the heater hose method is insufficient. It's worth a shot filling through the upper unless you'de rather go through the work of taking the heads off again.
10-16-2015, 03:22 PM
#15
You can't fill up through the expansion tank and expect to be full. lol Like foxsl said, you have to fill up through the upper radiator hose to get enough coolant behind the stat for it to open properly.
10-16-2015, 03:24 PM
#16
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
I haven't tried the heater hose route but I know what you mean now as far as the routing. However it doesn't make sense that the stat isn't opening despite being tested like the stuff I went through but it only indicates that the heater hose method is insufficient. It's worth a shot filling through the upper unless you'de rather go through the work of taking the heads off again.
What is a bit weird that the heater hoses were hot the first time. After i noticed the radiator return hose was still cold and changing the thermostat the heater hoses stayed cold. Could be an air bubble catched in the water pump....
10-16-2015, 03:27 PM
#17
Thats for sure. I'll do that tomorrow first.
What is a bit weird that the heater hoses were hot the first time. After i noticed the radiator return hose was still cold and changing the thermostat the heater hoses stayed cold. Could be an air bubble catched in the water pump....
What is a bit weird that the heater hoses were hot the first time. After i noticed the radiator return hose was still cold and changing the thermostat the heater hoses stayed cold. Could be an air bubble catched in the water pump....
10-16-2015, 03:32 PM
#18
Oh forsure so many air bubbles to evacuate. I had to run mine with the cap off for at least 30 minutes from filling the system from dry. I replaced a perfectly good water pump by thinking it was the issue because I didn't fill from the upper rad hose to the water pump. Just trying to save people from the same junk I went through.
10-16-2015, 03:41 PM
#19
Teching In
Thread Starter
iTrader: (2)
Join Date: Mar 2014
Location: Germany
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for all the support guys! 
I'll try the radiator hose fill methode first tomorrow and hope for a good outcome. Second i'll check with my buddy to clear things up with the right hand head gasket. Is there a way to tell from the outside???
I'll try the radiator hose fill methode first tomorrow and hope for a good outcome. Second i'll check with my buddy to clear things up with the right hand head gasket. Is there a way to tell from the outside???
