Oil in Coolant?

1. check coolant level inside the radiator - when cold.
2. check hoses for traces of leakage. if so, coolant can expand into
the bottle, but on cooling, suck air, so the bottle remains full.
3. if no hose leakage, have a head gasket test done.

 

This is one of several posts we've seen about this recently. I wonder what's
going on? However, check the coolant level in the radiator. If it is low,
replace the radiator cap. A leaky outer seal will cause the coolant to be
pumped into the reservoir and replaced by air in the radiator. If the air
gets trapped, the process will repeat.

The stuff isn't oil, though - that would be on top of the coolant.

Mike

 

I was looking at my coolant resevoir, and I noticed it was filled
nearly to the brim with coolant. I thought that was strange because it
normally isn't filled to the brim with coolant. I looked at the
bottom of it, and noticed that there was oil or black sludge at the
bottom. I pulled the dipstick out, and looked very closely to see if
any coolant seeped through. I was wondering if there may have been a
leak of some type? I don't know what this means. Can anyone shed some
light on this?

 

It's a 97 Honda Civic. 4 cylinder.

 

This happens because coolant is being blown into the reservoir but not
sucked back in again on cooldown.

Often this is a sign of a failed head gasket.

Check the coolant level in the rad. If it's low, you almost certainly have
a bad head gasket. Try replacing the rad cap first WITH OEM!

If a new rad cap doesn't fix it, have a garage perform a "pressure test"
(NOT a "compression test") on the cooling system.

You should take care of this _immediately_. A failed head gasket is
relatively inexpensive to fix as long as there is no collateral damage.
Keep driving and you _will_ cause that collateral damage.

 

Although it certainly does a good job of cleaning the carbon etc. off
the valves and piston in the cylinder that's getting the coolant
injected....

 

If the engine's been overheated much, that makes it more likely a
leaky head gasket.

 

Oh, yeah... That piston will get squeaky, shiny, new-looking.

 

I checked the radiator this morning, and it was full. I could see the
coolant.

 

You should definitely get that checked out asap. My friend’s 2003
Accord one day suddenly stalled - she took it to the shop, only to
find that her coolant was mixed with oil or something. Since she found
out when it was too late, she ended up paying a lot more than if she
had found out about it sooner ..

She ended up fixing that and trading in her Accord for the new CRV.

 

I once had a drunken mechanic pour a quart of oil into my radiator,
discovered months later when I happened to ask to have the radiator
flushed.

J.