Coolant puddle on intake manifold

[MikeB]

Yesterday I decided to take the MH into town to fill the tanks and give it my Monthly 40 minutes of driving. Before I left I looked at the motor and
found a few puddles sitting down on the right side of the intake manifold. It was probably a few table spoons in each lower indent. I soaked it up
with paper towel. I dint see any cracks or evidence of where it may have come from. There is one fairly new heater hose that runs on that side and
connects to the rear. I checked that hose for evidence, looseness of clamps and everything on it was clean and tight. After my in town run I checked
and there was no additional anti-freeze puddled. I also checked all hose connections, water pump, etc for signs of seepage and I didn't see anything.
The PO installed a new aluminum heavy duty WP from applied this last summer.

I couldn't see evidence of the source of the leak but I'm wondering if this is a symptom that y'all have seen before? Could coolant be seeping out at
manifold bolts?

The manifold is aluminum.

Thanks
Mike
--
M Beam
75’ Avion
TBI EBL , 3.70 LSD and other stuff
Zuki Sidekick,
Dozier Al

 

[Jim Hupy]

Depends upon which intake manifold you have, and whether or not your deck
surfaces and heads have been milled. If, that is the case, and the angles
between the intake and heads are not correct, and you have an early model
Rockwell manifold, your intake-to-head gaskets might easily be misaligned.
That can and does lead to antifreeze coolant leaks.
Jim Hupy
Salem, Oregon

On Sun, Nov 3, 2019, 2:20 PM mtb8114--- via Gmclist
wrote:

> Yesterday I decided to take the MH into town to fill the tanks and give it
> my Monthly 40 minutes of driving. Before I left I looked at the motor and
> found a few puddles sitting down on the right side of the intake manifold.
> It was probably a few table spoons in each lower indent. I soaked it up
> with paper towel. I dint see any cracks or evidence of where it may have
> come from. There is one fairly new heater hose that runs on that side and
> connects to the rear. I checked that hose for evidence, looseness of
> clamps and everything on it was clean and tight. After my in town run I
> checked
> and there was no additional anti-freeze puddled. I also checked all hose
> connections, water pump, etc for signs of seepage and I didn't see anything.
> The PO installed a new aluminum heavy duty WP from applied this last
> summer.
>
> I couldn't see evidence of the source of the leak but I'm wondering if
> this is a symptom that y'all have seen before? Could coolant be seeping out
> at
> manifold bolts?
>
> The manifold is aluminum.
>
> Thanks
> Mike
> --
> M Beam
> 75’ Avion
> TBI EBL , 3.70 LSD and other stuff
> Zuki Sidekick,
> Dozier Al
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[dennis sexton]

Just a caution
Before you drive any more check the oil for signs of coolant. If it's leaking outside it may also be leaking internally.

Dennis

> Yesterday I decided to take the MH into town to fill the tanks and give it my Monthly 40 minutes of driving. Before I left I looked at the motor
> and found a few puddles sitting down on the right side of the intake manifold. It was probably a few table spoons in each lower indent. I soaked it
> up with paper towel. I dint see any cracks or evidence of where it may have come from. There is one fairly new heater hose that runs on that side
> and connects to the rear. I checked that hose for evidence, looseness of clamps and everything on it was clean and tight. After my in town run I
> checked and there was no additional anti-freeze puddled. I also checked all hose connections, water pump, etc for signs of seepage and I didn't see
> anything. The PO installed a new aluminum heavy duty WP from applied this last summer.
>
> I couldn't see evidence of the source of the leak but I'm wondering if this is a symptom that y'all have seen before? Could coolant be seeping out
> at manifold bolts?
>
> The manifold is aluminum.
>
> Thanks
> Mike

--
Dennis S
73 Painted Desert 230
Memphis TN Metro

 

[jim kanomata1]

Pressurise the cooling system with a coolant pump up to 20-25 psi and watch
for leaks.
Should be able to rent one at a parts store.

On Sun, Nov 3, 2019 at 3:31 PM Dennis Sexton via Gmclist <

> Just a caution
> Before you drive any more check the oil for signs of coolant. If it's
> leaking outside it may also be leaking internally.
>
> Dennis
>
>

> > Yesterday I decided to take the MH into town to fill the tanks and give
> it my Monthly 40 minutes of driving. Before I left I looked at the motor
> > and found a few puddles sitting down on the right side of the intake
> manifold. It was probably a few table spoons in each lower indent. I soaked
> it
> > up with paper towel. I dint see any cracks or evidence of where it may
> have come from. There is one fairly new heater hose that runs on that side
> > and connects to the rear. I checked that hose for evidence, looseness of
> clamps and everything on it was clean and tight. After my in town run I
> > checked and there was no additional anti-freeze puddled. I also checked
> all hose connections, water pump, etc for signs of seepage and I didn't see
> > anything. The PO installed a new aluminum heavy duty WP from applied
> this last summer.
> >
> > I couldn't see evidence of the source of the leak but I'm wondering if
> this is a symptom that y'all have seen before? Could coolant be seeping out
> > at manifold bolts?
> >
> > The manifold is aluminum.
> >
> > Thanks
> > Mike
>
>
> --
> Dennis S
> 73 Painted Desert 230
> Memphis TN Metro
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502

 

[Ken B]

Do not get carried away with all of the difficult possibilities. Instead go look for the easy and most likely things first first.

For example look at hoses and hose connections. They are on top of the manifold and it is logical that they would puddle antifreeze there.

Next would be the thermostat housing and gasket. The one that really threw me off for a while was thermostat housing bolts. They go through the
housing and the manifold and into the coolant carrying area. I once had some leaking up through the threads of those bolts. The fix was simple.
Remove them one at a time and put some sealant on the bolt threads. I used aviation permatex.

After looking at all of that, then you can look at more difficult things to fix.

A cooling system pressure tester can also help by pressurizing the whole system COLD and watching for leaks WITHOUT the engine running. Do not go
over 10 PSI.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[johnny]

Also, do not think the tester set loaned by Advance will work. It won't. You will have to sacrifice a radiator cap and make it into an inlet for
pressure. Last resort that is.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[MikeB]

Thanks for the tips. I'll follow up when I find something out.
--
M Beam
75’ Avion
TBI EBL , 3.70 LSD and other stuff
Zuki Sidekick,
Dozier Al