Draining coolant when swapping headgaskets

pablon2

SCCoA Member
Does draining the radiator remove enough coolant out of the block such that the coolant level drops below the deck? I haven't had a HG failure (just swapping heads) and figured this time around I wouldn't drain the block (via pulling the knock sensor plug) if not needed.
 
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Roadhawg

Registered User
When I did heads on a 4.6L, I removed the lower radiator hose to drain most of the coolant.
Next I removed the intake manifold.
Then I used a Wet/Dry Shop Vac, with a smaller hose taped to the main hose removed the rest via the coolant passages on the heads.
 

ricardoa1

Registered User
Yep water will make down to the pan regardless. Once you pry the Lower manifold loose the water will leak into the block.

ALWAYS ALWAYS drain and fill the block with fresh oil then do it agin after start up for good measure.

I destroyed my stock motor, by doing a headswap and not changing the oil. One of three biggest mistakes I made with the car. :)
 

pablon2

SCCoA Member
In the past I pulled the knock sensor plug and let the block drain, but I am not sure if this drains both sides (having a senior moment here). Anyhow, by removing this plug I didn't have any coolant spill over the driver's deck when removing that head. I'm sure the best way to drain the block though is to remove the freeze plug on both sides. Surely this is not as messy as pulling the knock plug and then having coolant gush out onto the xmbr (it's a big hole).
 

Roadhawg

Registered User
On the driver's side the is a square pipe plug on the lower part of the block 2/3rds of the way back from the front.
It helps to have an 8 point socket to remove it.
 

pablon2

SCCoA Member
Passenger side remove knock sensor
Driver side remove square drain plug

Check that.....Passenger side remove knock sensor and then remove knock sensor mounting plug from block. It is easy to break the sensor connector if you try to remove everything at once.
 

ricardoa1

Registered User
:confused:

:confused:


Have you guys ever made an oil change in your car. :eek:

Remove the oil plug and watch the coolant fall down first then you will see the oil they dont mix, oil goes to the top. run fresh oil, Then drain and refill again for good measure.

What is this knock sensor removal thing? Water will go straight to the bottom. And the drain plug will get all of it out.
 

pablon2

SCCoA Member
:confused:

:confused:


Have you guys ever made an oil change in your car. :eek:

Remove the oil plug and watch the coolant fall down first then you will see the oil they dont mix, oil goes to the top. run fresh oil, Then drain and refill again for good measure.

What is this knock sensor removal thing? Water will go straight to the bottom. And the drain plug will get all of it out.

Ricardo, I'm not sure you are tracking here. As I stated in my first post, I am swapping heads and asking about removing coolant from the block. There was no HG failure here so there should be no coolant at this point in the oil pan. Yes, I will change oil once finished, but draining the oil pan now will not get coolant out of my block. ;)
 

ricardoa1

Registered User
Ricardo, I'm not sure you are tracking here. As I stated in my first post, I am swapping heads and asking about removing coolant from the block. There was no HG failure here so there should be no coolant at this point in the oil pan. Yes, I will change oil once finished, but draining the oil pan now will not get coolant out of my block. ;)
You are right I was not following at first,

I now follow but I feel its an unecessary step. The water jackets on the block can be easily lowered to the point where. It will not bother the seal. I guess if you want a super clean job then take the extra measurement.
 
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Mike8675309

Registered User
another data point.
I was able to get enough coolant out by pulling the lower radiator hose and spinning the water pump by hand to coerce the remaining coolant out. At least enough so that when I changed my intake manifold, there was no water at the coolant ports in the manifold, and coolant was not visible in the heads. Not sure how far it went as I can't recall where the front cover/water pump ports hit the block.
 

pablon2

SCCoA Member
I ended up draining the block. I'm glad I did b/c I noticed oil had gotten into my coolant from the manifold gasket (dang copper spray on the gasket...never again). Kinda funny, we always hear about coolant in the oil, but not so much about oil in the coolant. :p
 
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