LS-coupe cooling saga continues :(

[dville_gt]

The only thing left is the water pump right? What did it come off of?

Pump is the stocker off a 2005 Escalade LQ9. Only difference between it and stock is the top of it has been tapped for the cross-over hose that normally goes to the radiator.

Before anyone blames this for my issues, this is a common practice among the swap guys and "2165 Turbo Rail" with the GTO has his pump done the same way and stays cool (even with a turbo/intercooler adding additional heat). In addition, I only drilled/tapped it after I switch from the f-body radiator to the double pass that has no provision for a crossover tube.

[CRASH]

funny you should show up I was just talking about you

Good things, I hope ! Lol ! How ya been, Paul ?

-Aaron

[jw33]

That's the only thing I can come up with. I know without any doubt that that radiator is more than enough to cool the engine and the airflow is fine.

[greenbullitt]

The only thing left is the water pump right? What did it come off of?

We were just discussing that. I suspect cavitation, id like to see the inside of the pump.Either that or theres some nasty shit in the block casting needing to be flushed. I think im gonna borrow the vacuum bleeder from my buddy as well.

[jw33]

The only thing left is the water pump right? What did it come off of?

[dville_gt]

block test came back negative for blown h/g, per greenbullitt's advice i took my old thermo and took out the insides turning it into simply a restrictor plate, no difference.

[greenbullitt]

When I bought the '86 GT that I recently sold to Yale, it would get hot when running the A/C, but didn't show any obvious signs of having a blown head gasket. Took it to Paul and we did the test kit and sure enough, there was exhaust gas in the coolant. Turns out both head gaskets were blown.

-Aaron

funny you should show up I was just talking about you

[CRASH]

Ya, brand new GM MLS head gasket with new TTY GM bolts

Where are you located? I am in N. Arlington off i30.

If this turns out to be a blown h/g I am going to be really surprised. I had an LT1 blow a h/g where the only symptom was it pressurized the cooling system after being turned off hot. But it would over heat in a totally different manner. This is a super gradual deal, for example yesterday evening I drove about 5 miles, temp was between 180-200, sat idling in a parking lot a/c on for about 5 minutes, temp stayed around 210, got on highway, temp around 220, got off highway and temp went 230+ so I took it home.

Plugs look good, motor runs strong, coolant looks good, oil looks good, has never puked coolant, never started detonating, never seen bubbles in the coolant, etc.

When I bought the '86 GT that I recently sold to Yale, it would get hot when running the A/C, but didn't show any obvious signs of having a blown head gasket. Took it to Paul and we did the test kit and sure enough, there was exhaust gas in the coolant. Turns out both head gaskets were blown.

-Aaron

[dville_gt]

https://napaonline.com/Catalog/Resul...&Dk=1&Dp=3&N=0

pm me if you want to borrow one.

Also, when you pulled the head for that broken bolt, did you replace the head bolts?

Ya, brand new GM MLS head gasket with new TTY GM bolts

Where are you located? I am in N. Arlington off i30.

If this turns out to be a blown h/g I am going to be really surprised. I had an LT1 blow a h/g where the only symptom was it pressurized the cooling system after being turned off hot. But it would over heat in a totally different manner. This is a super gradual deal, for example yesterday evening I drove about 5 miles, temp was between 180-200, sat idling in a parking lot a/c on for about 5 minutes, temp stayed around 210, got on highway, temp around 220, got off highway and temp went 230+ so I took it home.

Plugs look good, motor runs strong, coolant looks good, oil looks good, has never puked coolant, never started detonating, never seen bubbles in the coolant, etc.

[greenbullitt]

https://napaonline.com/Catalog/Result.aspx?Ntt=block+test+kit&Ntk=Keyword&Nty=1&Dn=0&D=block+test+kit&Dk=1&Dp=3&N=0

pm me if you want to borrow one.

Also, when you pulled the head for that broken bolt, did you replace the head bolts?

[dville_gt]

After a second look, I'm wondering if that radiator is actually doing it's job. Since both upper and lower hoses are on the same side, it doesn't force the water across the core and the non cooled water could just be circulating back into the engine. That would explain it be good at first but then slowly creeping up in temp.. If you notice on f bodies, the upper hose goes across the bay just to get to the other side of the radiator.. Hate to say it but maybe try a different radiator with the inlet and outlet on opposite tanks...

It is a double pass radiator, there is an internal baffle on the side of the tank with the inlet out let, the coolant must pass across one 1" core, then in the turns around in the opposite tank and goes back across a second 1" core before going back to the engine. They actually have triple pass as well that the inlet ends up on the opposite side as the outlet where the coolant actually makes 3 passes across the radiator.

[Blackpony]

After a second look, I'm wondering if that radiator is actually doing it's job. Since both upper and lower hoses are on the same side, it doesn't force the water across the core and the non cooled water could just be circulating back into the engine. That would explain it be good at first but then slowly creeping up in temp.. If you notice on f bodies, the upper hose goes across the bay just to get to the other side of the radiator.. Hate to say it but maybe try a different radiator with the inlet and outlet on opposite tanks...

[dville_gt]

Might as well thow on a set of 243's....

Still got yours? Bad luck special possibly?

Going to pick up a combustion leak tester and see whats up.

[jw33]

Might as well thow on a set of 243's....

[dville_gt]

not sure if others are closer, but i have one

Where are you at?

If it is too far I might just buy a kit, I know the kits are around $30 at Napa (at least that's what I paid a few years ago when I bought one). Guess I'll call tomorrow and figure out what they go for now. Probably not bad to have around for these instances.

Guess I'll have to pull both heads if it ends up being an H/G since the plugs all the plugs look good and there is no good indicators of a h/g thus no way to tell which head it is.