Best way to clean oil out of cooling system?

speeder · 03-11-2012, 11:48 PM

I have a project car that blew a head gasket and contaminated the cooling system with oil. I'm doing the HG job and plan on replacing the coolant tank and hoses but still need to flush-out the block and heater core, etc.

I've been give advice to use automatic DW detergent, (like Cascade), because it is low sudsing. Not sure how much grease-cutting power it has. This would be just run through the system hot for a short while after reassembly and then flushed with clean water.

I was thinking liquid Tide. It's also low-sudsing and definitely cuts grease and oil. It's what I use on my clothes and I'm a grease monkey.

What's best to use?

Heel n Toe · 03-12-2012, 12:10 AM

Shouldn't a common radiator flush product do the job, Denis?

Rick V · 03-12-2012, 01:47 AM

Simple green and water. It will take a few flushings to get all of that solution back out of the system but it does clean.

wdfifteen · wdfifteen's Garage

How important is it to get it sparkling clean?
I don't know whether regular radiator flush would help much. There isn't supposed to be oil in the cooling system so it probably doesn't have a lot of oil removal capacity. Dishwashing detergent or laundry soap made for front loading washers is what I would use plus maybe add a little TSP for the phosphate. But I wouldn't worry about it too much. What's a little oil going to hurt?

billybek · billybek's Garage

There are products available to do this job, but I have seen somewhere that a tablespoon or two of dishwashing powder will do a pretty good job of this. YMMV!

RANDY P · RANDY P's Garage

Liquid Shout stain remover is what one dude with a C36 used.

rjp

VINMAN · 03-12-2012, 07:53 AM

Denis , I would think any of the citrus or "purple" cleaners would do a good job.

Mrmerlin · 03-12-2012, 07:53 AM

also count on replacing all of the rubber hoses after you clean the system, the oil will weaken and soften the coolant hoses and you may have one or more split or slide off its connection point BTDT

Liquid Tide seems to work well for flushing and it doesnt have the caustic ingredients that simple green has so less chance of head gasket damage

1990C4S · 03-12-2012, 09:36 AM

Quote:

Originally Posted by wdfifteen

How important is it to get it sparkling clean?
.... What's a little oil going to hurt?

If there is residual oil you will never know if the problem reoccurs. Otherwise I wouldn't worry about it too much.

red-beard · red-beard's Garage

Dishwashing detergent attacks aluminum. I'd be careful.

speeder · 03-12-2012, 10:11 AM

Quote:

Originally Posted by red-beard

Dishwashing detergent attacks aluminum. I'd be careful.

This is one concern of mine. I love Simple Green for general cleaning but I've heard, (or read here), that it is not kind to aluminum. I'm leaning towards liquid Tide and water.

Why does it need to be clean? For one thing, it's a bloody mess. I'm pretty fastidious about clean coolant in engines/cooling systems. When I was into Powerstroke diesels, lots of guys on the PSD boards ran bypass filters on their cooling systems to remove contaminants, like big rigs have. It has an extra importance on diesels but I'm OCD about coolant on anything.

The other 2 reasons are because the entire system on this engine is suspect in terms of water jackets having crap in them and the fact that any oily residue negatively affects cooling efficiency. This is why the optimum mixture in most systems is less than 50% coolant/H2o. Water transfers heat better than oily coolant, though coolant is necessary for its other benefits. (Higher boiling point/lower freezing point). If I'm in a cold place in the winter, I run 50/50 mixtures. In hot climates, more like 35/65%, coolant/distilled water.

speeder · 03-12-2012, 10:12 AM

Quote:

Originally Posted by Mrmerlin

also count on replacing all of the rubber hoses after you clean the system, the oil will weaken and soften the coolant hoses and you may have one or more split or slide off its connection point BTDT

Liquid Tide seems to work well for flushing and it doesnt have the caustic ingredients that simple green has so less chance of head gasket damage

Absolutely going to replace all soft parts and probably the radiator.

MarkRobinson · 03-12-2012, 11:04 AM

Quote:

Originally Posted by red-beard

Dishwashing detergent attacks aluminum. I'd be careful.

Yes it does! Do not use that.

I'd do a water flush first, over-fill the expansion tank, the oil will rise to the top & get burped out the over-flow.

Simple green works well: I'd do a 1/2-1/2 flush with simple green should remove most all oil in it as well.

I'd check the over-the-counter flushers as well: most should tackle oil since water/oil mixing is very common. I'd flush once/twice or until all floating oil (on top of the water) is gone.

Mark

speeder · 03-12-2012, 11:57 AM

So Mark, what about SG and aluminum? Someone on this board was saying that it's banned from aviation shops because of its Ph and aluminum. I've personally never had a problem using it diluted to clean under hoods, other degreasers I have seen etch aluminum.

Thanks for all the replies, keep 'em coming!

MarkRobinson · 03-12-2012, 12:02 PM

I'ved used SG for years w/o ever seeing any chemical reminants of etching or other aluminum issues, though I have Tide & water in my parts washer: left a 928 WP in there for a week & there was so much corrosion that the impeller wont spin. Ouch!

To be safe, check the autoparts stores first for radiator flush that focus on oil removal & are aluminum safe.

speeder · 03-12-2012, 12:06 PM

Will do. Thanks.