Heater core flush

[Hoosierkav]

I flushed the system earlier in the year; looking at the coolant I collected, there's a bit of oil on the surface. Is it possible that oil has stuck on and baked onto the core, decreasing its effectiveness? I'm at least the 3rd owner of the vehicle and who knows how long it's had whatever issue it has, so this could be a multi-year issue.

Thoughts on that being a problem, and using a degreaser to flush the core?

And, yes, I have heat, but my toes still say they want more.

 

[churchmouse]

I flushed the system earlier in the year; looking at the coolant I collected, there's a bit of oil on the surface. Is it possible that oil has stuck on and baked onto the core, decreasing its effectiveness? I'm at least the 3rd owner of the vehicle and who knows how long it's had whatever issue it has, so this could be a multi-year issue.

Thoughts on that being a problem, and using a degreaser to flush the core?

And, yes, I have heat, but my toes still say they want more.

1st.....what kind of car.
2nd.....does it have a valve that controls the flow when you set the heat. Is it going full stroke.
3rd.....is there a restrictor in the hose to slow the water down as it goes through the core.
4th....T-Stat. Is it the right one and is it working.
Where did the oil come from...?????

 

[Jaybird1980]

5. Does it have an engine oil cooler, cooled with antifreeze.
6. Does it have trans fluid cooler in the radiator.

Check your oil and trans fluid for condition and level

 

[churchmouse]

5. Does it have an engine oil cooler, cooled with antifreeze.
6. Does it have trans fluid cooler in the radiator.

Check your oil and trans fluid for condition and level

Good points. I missed those.

 

[Sigblitz]

7. Gasket leak between water jacket and cylinder.

 

[marvin02]

If your car is newer and has a trans cooler any transfer of anti-freeze to the trans could go undetected with a sealed trans and can cause transmission failure. Nissan had a big problem with this on their Frontier trucks. If you are losing anti-freeze and can not detect where it is going you need to get it checked ASAP.

 

[Jaybird1980]

7. Gasket leak between water jacket and cylinder.

While this is true, it is worse case. Condition of current fluids would be where to look. Combustion chamber leak would be indicated by severely discolored coolant as well. If the coolant is proper color but with just a slight rainbow sheen that is normal. Ethylene glycol has synthetic oils in there makeup for lubrication and rust prevention. Check all fluids to make sure they are normal.
As far as flushing the heater core, have at it just use low pressure. Garden hose will be sufficient to flush out sediments.

 

[Hoosierkav]

'98 Expedition Eddie Bauer. I'll have to check for the other coolers.

When I look in the overflow container, the top of the coolant has some sort of shmutzy scum.

 

[Robert Richardson]

Sounds normal to me. Extended life coolant gets very nasty and scummy looking.

 

[Jaybird1980]

It can look pretty bad as RR said, may be time to change it.

 

[churchmouse]

Sounds normal to me. Extended life coolant gets very nasty and scummy looking.

Especially if that is original.

If it has been changed and stated as much I missed that.

 

[Hoosierkav]

It's been flushed.

 

[Fixer]

Typically you remove the heater core from the loop when flushing the system. The core has much smaller passages and can collect sediment from the rest of the system when flushing. You can try removing the hoses from the core and flushing it from both sides to see what comes out. I replace the thermostat when I flush the coolant so everything is working as well as it should.
Oil in the coolant will look like grey sludge pudding.

 

[WanderingSol07]

Years ago I had no heat in my '66 Ford Falcon. Went to replace the core, bought a new core, took out the old core and decided to see how it reacted to a garden hose flush. I held the hose to the core, but nothing went in or came out. I duct taped the host to the core and turned on the hose, nothing, turned it on more, and then this gray/brown sludge started to ooze out. Took about 5 minutes to get the crap out and then it started flowing freely. I flushed it both ways until the water flowed clear and a bucketful was clear. I put the old core back in and never had an issue. I wonder what was still in the engine?

 

[churchmouse]

Years ago I had no heat in my '66 Ford Falcon. Went to replace the core, bought a new core, took out the old core and decided to see how it reacted to a garden hose flush. I held the hose to the core, but nothing went in or came out. I duct taped the host to the core and turned on the hose, nothing, turned it on more, and then this gray/brown sludge started to ooze out. Took about 5 minutes to get the crap out and then it started flowing freely. I flushed it both ways until the water flowed clear and a bucketful was clear. I put the old core back in and never had an issue. I wonder what was still in the engine?

The engine has much much larger cooling passages. The crap always finds the core. I have used this method a few times myself on older cars. But I refrain to suggest it after telling a friend and he ruptured the core in his 1996 Impala SS by not being patient . Put the hose to it full throttle and ruptured the core. Water every where in the floor boards. He was actually mad at me for his not following instructions.
Older cores might be weaker with age and improper care to the system.