Filling coolant reservoir 3.0 TKS?

[Jonatande]

I just bought a 3.0 TKS and did an engine check. Saw the coolant reservoir was a little low when engine was in normal tempratures.

However, never refilles coolant and want to check.
1. Is it fine to fill it up without draining the system? Or should I wait to after season and completly change all coolant?
2. Manual mention filling coolant reservour tube can cause air pockets if the part if engine is not higher than rear? My engine is of course flat so what does it mean?

 

[Scott Danforth]

welcome aboard

so you have a heat exchanger?

are you looking in the expansion tank on the heat exchanger, or the puke tank along the side of the engine?

the expansion tank should be full at all times.
the puke tank will have just a trace of coolant when the engine is cold, and be close to full when the engine is warm. This is because Mercruiser doesnt understand the 10% expansion and 6% draw-down effect of cooling systems and deareation

if the puke tanks is low and the expansion tank is low, you have either a leak or it was overheated to push coolant out the puke tank vent

top off the HX expansion tank with a 50/50 mix when its cold and put a splash in the bottom of the puke tank.

then run it, and run it hard, WOT under load

if all is normal, there will be no bubbling of coolant, the puke tank will not overflow, and when the engine cools, there will be a trace amount in the puke tank

if something is awry, the puke tank will bubble up, puke coolant in the bilge

 

[achris]

Check to ensure that the reservoir you're looking at actually has coolant in it, not gear oil.

Chris...

 

[nola mike]

How many cc 3.0's are out there?

 

[achris]

How many cc 3.0's are out there?

Not a lot, but plenty with drive oil monitor bottles....

 

[Jonatande]

Check to ensure that the reservoir you're looking at actually has coolant in it, not gear oil.

Chris...

It's kind of brownish - why would gear oil come into the coolant?

 

[Jonatande]

welcome aboard

so you have a heat exchanger?

are you looking in the expansion tank on the heat exchanger, or the puke tank along the side of the engine?

the expansion tank should be full at all times.
the puke tank will have just a trace of coolant when the engine is cold, and be close to full when the engine is warm. This is because Mercruiser doesnt understand the 10% expansion and 6% draw-down effect of cooling systems and deareation

if the puke tanks is low and the expansion tank is low, you have either a leak or it was overheated to push coolant out the puke tank vent

top off the HX expansion tank with a 50/50 mix when its cold and put a splash in the bottom of the puke tank.

then run it, and run it hard, WOT under load

if all is normal, there will be no bubbling of coolant, the puke tank will not overflow, and when the engine cools, there will be a trace amount in the puke tank

if something is awry, the puke tank will bubble up, puke coolant in the bilge

Ok thank you!

Basically in the manual it says I should fill number 2 in order to refill coolant. I REFER # TO IMAGE ATTACED BELOW.
1.
#2 has a COLD and HOT mark on it. It says coolant level should be below COLD-mark when engine cold and below HOT when engine hot. Not full as you stated. However, At the moment it is still below COLD despite letting the engine idle and showing mid-temprature on the panel.

Also, this should be done when engine is on in normal operating temprature?


2.
I heard you should not refill #1 directly but it will get refilled automatically when you refill #2.

 

[Scott Danforth]

It's kind of brownish - why would gear oil come into the coolant?

if your coolant is brownish, flush the system.

it should either be green or orange. however if you mix green with orange, you get a brown sludge.

or if you have rust in your system, you have brown coolant

Ok thank you!

Basically in the manual it says I should fill number 2 in order to refill coolant.
1.
#2 has a COLD and HOT mark on it. It says coolant level should be below COLD-mark when engine cold and below HOT when engine hot. Not full as you stated. However, At the moment it is still below COLD despite letting the engine idle and showing mid-temprature on the panel.

Also, this should be done when engine is on in normal operating temprature?


2.
I heard you should not refill #1 directly but it will get refilled automatically when you refill #2.

when you first fill the system, you need to fully fill the system. there is no way to fill the system from the overflow tank. you must fill the system from the heat exchanger

when engine is cold, in the morning, open the cap on the expansion tank on the HX. the coolant should be all the way to the top and there should be a bit of coolant in the bottom of the reservoir.

if you have a problem, it will not draw from the overflow tank - AKA the puke tank.

any cooling system designed with an overflow tank is improperly designed with regards to expansion volume and draw-down volume. however its cheaper to do it that way.

 

[Jonatande]

if your coolant is brownish, flush the system.

it should either be green or orange. however if you mix green with orange, you get a brown sludge.

or if you have rust in your system, you have brown coolant



when you first fill the system, you need to fully fill the system. there is no way to fill the system from the overflow tank. you must fill the system from the heat exchanger

when engine is cold, in the morning, open the cap on the expansion tank on the HX. the coolant should be all the way to the top and there should be a bit of coolant in the bottom of the reservoir.

if you have a problem, it will not draw from the overflow tank - AKA the puke tank.

any cooling system designed with an overflow tank is improperly designed with regards to expansion volume and draw-down volume. however its cheaper to do it that way.

Thanks for the patience I think I start to understand.

I will open the thermostat on expanion tank to take a look later today but looks like reservoir then may function properly. If expansion tank is full then no need for refill?


Dunno about the color though (see pictures)

 

[Scott Danforth]

Thanks for the patience I think I start to understand.

I will open the thermostat on expanion tank to take a look later today but looks like reservoir then may function properly. If expansion tank is full then no need for refill?


Dunno about the color though (see pictures)

take a sample of the coolant in a clear container to look.

cant see thru the opaque white tank

 

[Jonatande]

take a sample of the coolant in a clear container to look.

cant see thru the opaque white tank

Thanks - Would this be good level?

 

[Scott Danforth]

No, it should be full to the bottom of the lip.

You have an air pocket in there

Looks line you are about a half pint down

 

[Jonatande]

No, it should be full to the bottom of the lip.

You have an air pocket in there

Looks line you are about a half pint down

Ouch! This was in complete cold condition.

Any suggestion what to do? It’s already in water so want to avoid draining it. Just refill up to the top with new coolant liquid and then change everything after season?

 

[Scott Danforth]

Ouch! This was in complete cold condition.

Any suggestion what to do? It’s already in water so want to avoid draining it. Just refill up to the top with new coolant liquid and then change everything after season?

pour 50/50 mix of coolant into the HX until its full (about half a pint), put a bit in the bottom of the jug (about half a pint)

Just like I stated in post #2 and #8

and go boating

 

[Jonatande]

take a sample of the coolant in a clear container to look.

cant see thru the opaque white tank

Tested the boat for a long journey this weekend and think temprature were just fine (see pictures). But a bit worried about the coolant recovery tank condition. As you can see - coolat is right on bottom (cold engine).

1. I checked your steps but I heard it good be a problem to refill if I don’t know what type of coolant is already and their and thus avoid mixture. Maybe not a problem if I plan to drain after season?

2. I am also not sure of ”airpocket” avoidance measure. Does airpocket go away with high idling? And it says the front of engine needs to be in a higher position when you refill to avoid it which is hard on water and that I dont know what the front of engine is at.

 

[Scott Danforth]

Tested the boat for a long journey this weekend and think temprature were just fine (see pictures). But a bit worried about the coolant recovery tank condition. As you can see - coolat is right on bottom (cold engine).

1. I checked your steps but I heard it good be a problem to refill if I don’t know what type of coolant is already and their and thus avoid mixture. Maybe not a problem if I plan to drain after season?

2. I am also not sure of ”airpocket” avoidance measure. Does airpocket go away with high idling? And it says the front of engine needs to be in a higher position when you refill to avoid it which is hard on water and that I dont know what the front of engine is at.

if your coolant is green, you add green to it
if you coolant is orange, you add orange to it

if you cant figure out the color, you change it and follow the manual

if you just need to top it off a bit, simply add a few ounces of water.

 

[Jonatande]

if your coolant is green, you add green to it
if you coolant is orange, you add orange to it

if you cant figure out the color, you change it and follow the manual

if you just need to top it off a bit, simply add a few ounces of water.

Thanks!

My coolant reservoir is yellow but my recovery tank is brown because it is completly clogged….

I will top up as described in initial post and go with water, fix my recovery tank and hose then drain the system in end of season and refill completly.

 

[Scott Danforth]

pull the puke tank and rinse it out.

 

[Scott06]

Thanks!

My coolant reservoir is yellow but my recovery tank is brown because it is completly clogged….

I will top up as described in initial post and go with water, fix my recovery tank and hose then drain the system in end of season and refill completly.

My advice top it with the premixed ‘use with any kind of antifreeze’ antifreeze..

At end of season drain flush and refill new

 

[Scott Danforth]

My advice top it with the premixed ‘use with any kind of antifreeze’ antifreeze..

At end of season drain flush and refill new

you cant mix green and orange. you get a sludge that precipitates out