Rust in coolant

On a routine coolant change, I noticed that the radiator is spewing out
a lot of rust. I filled and drained the coolant a couple of times, but
there still seems to be a lot of it.

The rust wasn't there during the last coolant change. What could have
caused it? Is it a bad sign?

 

did you use OEM coolant? Premix? or tap water?

 

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Now you know where your 10 mm combination wrench went missing

Cheap coolant diluted with tap water sounds like the cause.

'Curly'

 

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Now you know where your 10 mm combination wrench went missing

Cheap coolant diluted with tap water sounds like the cause.

'Curly'

 

What kind of car are you talking about. A 67 Bug doesn't use coolant...

Earle

 

What kind of car are you talking about. A 67 Bug doesn't use coolant...

Earle

 

Very sharp, Earle But I was asking about a 94 Civic 1.5 liter.

Curly, yes indeed, it was filled with cheap "Whiz" coolant (and
distilled water). But I was nervous because I read a post that said
that rust is a classic sign of past overheating. AFAIK this car has
never overheated on me, the temp needle never event went up halfway. So
it's definitely the Whiz, and not overheating?

 

Very sharp, Earle But I was asking about a 94 Civic 1.5 liter.

Curly, yes indeed, it was filled with cheap "Whiz" coolant (and
distilled water). But I was nervous because I read a post that said
that rust is a classic sign of past overheating. AFAIK this car has
never overheated on me, the temp needle never event went up halfway. So
it's definitely the Whiz, and not overheating?

 

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In some countries, it's considered impolite to even mention that you put
Whiz in your cooling system . :-(

I'm repulsed ! !

'Curly'

 

---------------------------------------
In some countries, it's considered impolite to even mention that you put
Whiz in your cooling system . :-(

I'm repulsed ! !

'Curly'

 

wrote in @m7g2000cwm.googlegroups.com:

If it is in fact rust you see and not simply discoloration, you have a
giant problem with your engine. However...

If you switch colors of antifreeze and do not make certain every trace of
the old stuff is flushed out, the new stuff will be contaminated and may
look a rusty brown.

Did you remove the block drain and flush the entire system until the water
ran clear before refilling?

Is the rusty fluid clear or cloudy?

 

wrote in @m7g2000cwm.googlegroups.com:

If it is in fact rust you see and not simply discoloration, you have a
giant problem with your engine. However...

If you switch colors of antifreeze and do not make certain every trace of
the old stuff is flushed out, the new stuff will be contaminated and may
look a rusty brown.

Did you remove the block drain and flush the entire system until the water
ran clear before refilling?

Is the rusty fluid clear or cloudy?

 

rust? that's bizarre. the cylinder block is aluminum, the steel
cylinder liners are cast into aluminum and have no direct contact with
the coolant, the radiator and heater cores are not steel... the only
things that are steel and in contact with the coolant are the drain
plug, the expansion cores and the coolant pump impeller. and they're
all plated. if those are rusting sufficiently to discolor the coolant,
you may have a serious problem on your hands!

double check to see what this material is - a magnet should do it.
/definitely/ use a quality antifreeze and distilled water.

 

rust? that's bizarre. the cylinder block is aluminum, the steel
cylinder liners are cast into aluminum and have no direct contact with
the coolant, the radiator and heater cores are not steel... the only
things that are steel and in contact with the coolant are the drain
plug, the expansion cores and the coolant pump impeller. and they're
all plated. if those are rusting sufficiently to discolor the coolant,
you may have a serious problem on your hands!

double check to see what this material is - a magnet should do it.
/definitely/ use a quality antifreeze and distilled water.

 

I could have sworn the last Honda 4-cylinder I saw had the iron cylinders
sitting bare-naked in the coolant. They were cast as a siamesed block of
four, and were fully exposed all the way down until they got buried in the
aluminum at the bottom.

 

I could have sworn the last Honda 4-cylinder I saw had the iron cylinders
sitting bare-naked in the coolant. They were cast as a siamesed block of
four, and were fully exposed all the way down until they got buried in the
aluminum at the bottom.

 

nah, the actual steel liners are real thin - maybe 3mm - and the rest of
the siamese quintuplets are the alloy casting they sit in. it's an
unusual arrangement for sure. if you're doing a gasket scrape, it's
easy enough to test what's where because the soft alloy bit can be
scratched by the blade, the steel bit not. i'll see if i can take a pic
next time i'm in a junk yard.

 

nah, the actual steel liners are real thin - maybe 3mm - and the rest of
the siamese quintuplets are the alloy casting they sit in. it's an
unusual arrangement for sure. if you're doing a gasket scrape, it's
easy enough to test what's where because the soft alloy bit can be
scratched by the blade, the steel bit not. i'll see if i can take a pic
next time i'm in a junk yard.

 

I don't know where you read this, but there isn't that much iron in a Civic
engine, not where the coolant can get to it. Maybe the cylinder walls, but
if they are rusted up you have serious problems.

I would flush the system. Use the owner's manual instructions, if you still
have it. Fill it with Honda Genuine Coolant. It only takes a gallon of
pre-mix, and there are too many different types of coolant out there, to
take chances.

Earle

 

I don't know where you read this, but there isn't that much iron in a Civic
engine, not where the coolant can get to it. Maybe the cylinder walls, but
if they are rusted up you have serious problems.

I would flush the system. Use the owner's manual instructions, if you still
have it. Fill it with Honda Genuine Coolant. It only takes a gallon of
pre-mix, and there are too many different types of coolant out there, to
take chances.

Earle