[Vwdiesel] Oil in cooling system

Sandy Cameron scameron at compmore.net
Sat Feb 10 23:53:43 EST 2007

At 07:27 PM 10/02/2007 -0600, you wrote:
>Has anyone devised a safe method for flushing motor oil (bad Hd. Gasket)
>from the cooling system? Also, what's the latest thinking on Hd. Gasket
>installation, install dry or use a sealer? What kind of sealer if used?

Re; Installing gasket NO SEALER !.  But ensure head and block surfaces are
clean and dry.

I had to do dyalasis on my son's 91NA.

It's gasket was not blown from a combustion chamber, but it constantly
leaked oil, as revealed when I changed the gasket, due to a malformation of
the rubber insert in the gasket that seals the oil riser to the head.

The inside of the cooling system was a mess! to say the least. An oil cooled

First, I changed the head gasket.


I pondered this for a few days, and settled on this trick whiich worked
well, cleaned the heater core, radiator, engine jacket, and the inside of
the hoses, without removing any of them from the car, and with the engine
running so it would stay hot, and the water pump would circulate everything
with reasonable velocity.

It was also necessary to get the system up to temperature so I could flush
the rad without removing the thermostat.

Equipment used:

-Small submersible sump pump, (the kind with a garden hose fitting on its exit)
-4 gal bucket full of hot water mixed with one bottle of "Simple Green), a
water-soluable surfactant degreaser. Usually available at larger auto supply
(Canadian Tire Corp here in Canada)

-Extra buckets of Hot water as required, "Enema until clear", as the nurses say.

My engine came clean on the third bucket.

I disconnected the heater hose between the outlet of the head and the heater
input, connected the dyalasis apparatus, pump output to heater input, outlet
from head to drain in to the bucket.  Take the top off the reservoir (I
actually had my reservoir in the house for laundering, NO I didn't put it in
the dishwasher :)
I cant remember if I plugged the reservoir hoses, I think likely, as they
would squirt when the sump pump is running


a/ use heat resistant hose, rubber with cord re-inforcement if available.
The plastic I used went limp with the heat and was difficult to manage,
folding and kinking.

b/ Find a container and a skimming vessel to skim the oil off the top of the
water as it comes out. I got almost a quart.

I started with a dry engine, I recommend draining anything that's in the
cooling system first, it will not be re-useable, and will just
re-contaminate the insides.

Set the pump in the bucket and turn it on. You may/will  have to add more
hot water to the bucket as it fills the engine and rad, etc.
When you have a good flow returning from the engine to the bucket, start the
engine and let it run at high idle. You can turn on the head lights and rear
window heater to give it something to do, it will heat faster that way.
Turn off the cabin heater fan so it doesn't suck away the heat. 

Make sure all your hoses, etc are secure, use clamps at the joints, tie off
runs so they dont kink, flop or fly away.If anything comes apart, you will
have a hell of a mess to clean up. And you are working with scalding water
temperatures. I did this in my heated garage because it was december. I did
not have a spill. Remember the Exxon Valdeze?

All standard cautions and disclaimers apply.

The oil will come out in gobs for a while and float to the top of the hot
water in the pail.
Carefully Scoop it out into a container. The return flow will clear up after
a while, but wait until the thermostat opens, when a lot more oil will come
out. I think there was more in the rad than in the engine. It's OK to shut
off the pump (have a means near by to do this, in case TSHTF) and engine
while you do the other chores like dipping and changing the water.

When you think you have got most of the oil flushed out, time to change the
                                                         HOT ! !
I just changed the water in the pail, as the water remaining in the engine
was grey, but not oily. Ran it again for a while until no more oil came out,
then flushed it again with clean water to get rid of the grey (soot).

After this is all over, disconnect the lower rad hose, and one of the other
hoses from the water pump to drain the system. Blow some low pressure air
thru the heater core to blow the water out of it. It can not drain by gravity.

When all the water is gone, replace all hoses and clamps, and fill with new,
long life antifreeze, run the engine until the T-stat opens, keep topping up
until it no longer goes away.

The antifreeze in junior's car is still pale orange, with NO oil spots a
month later.

Be sensible about disposing of the oil and water. If you skim the oil
carefully, you can probably dispose of the water in any drain or sewer, or
on a long gravel driveway.

The simple green is labeled biodegradable, and the small amount of suspended
soot will do no harm.


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