Recently bought a 1998 Volvo S70 T5 with minor front end wreck damage and bad oil contamination in cooling system. Supposedly, oil cooler had ruptured/leaked into cooling system ( Water Reservoir severly filled with "sludge". The Radiator was replaced ( appears to be new ), But I have no idea about a "Flush" having been done (Owner is in Iraq and it was sold, for him, by his brother), It will run and slowly begin to overheat ( no skipping, as if headgasket problem). Let it cool down and with plugs removed, there is no sign of moisture coming from cylinders.
I was considering draining the cooling system and doing a major "Flush". Changing the oil and filter, at the same time. I have a reservoir and associated hoses on the way. I also have some info on using "Cascade Dish Washing Liquid" or a Marine Type "Bilge Cleaner for the Flush. I have heard that the heating system should be closed ... but, "Back in the Day, we always opened them. >> Any Comments Appreciated, on this". Any procedural "hook-Ups" will be appreciated or any "D.I.Y. tools that might be dandy. We ran a foreign car repair shop for years and I'm also a Weldor ...... having made 90% of the "specal tools" that I needed.
I still has some older Volvos "hidden" behind the house and have acquired a few of the later ones, as possible future projects. I always felt I'd like to "Go out" in a Volvw, rather than some high dollar casket.
Thanks prematurely and "Keep at least one Volvo on the road at all times!

 

I have never heard about a dishwashing liquid flush. To me it sounds like you are on the right track. If it's overheating, maybe pull the t-stat out and see if that changes anything. Also, there should be a fan that cuts on at a certain temp to aid in cooling.

 

Dishwashing soap is a fine degreaser, BUT I would worry about all the bubbling and not getting it out. There has to be something better out there. I really wanted to weigh in on the heater - there's going to be sludge in there and it has to go. you don't want to block any flow through the heater core.

 

Another thing to consider is that you rarely get cross-contamination in a situation like this. What I mean is, unless the block has a crack you can't see, you should ONLY have oil in your coolant, OR coolant in your oil. Fortunately, having oil in the coolant causes a slow death, whereas water in your oil typically kills a car more quickly.

I do NOT like your dishwashing detergent idea at all. I think there are a lot of products that won't foam in your system quite as much.

I advise you to look into biodegradeable (i.e. WATER SOLUBLE) liquid products that you would use to clean oil off of your garage floor. You want something that will break down the oil, but rinse away cleanly and easily.

Dishwashing detergents make lots of bubbles because that's what housewives want to see when they're doing dishes. Bubbles are happy, and let you know that there's still cleaning power left in the sink full of dishwater. Men who are flushing a coolant system don't care about happy bubbles. They only care about getting as much nasty black gritty crap to flow out of that coolant line as possible.

You might even do well to try a plumbing supply store. The stuff a guy uses to clean the food grease out of a restaurant drain might work well for you, too.

Just my $.02 hope it helps!

Cheers,
LG

 

Thanks to all above. I have defintely considered the "FOAM" and it's residue, That is why I am investigating the "Bilge Cleaner" that is used in many boat's Internel Engine Bays, with great success, I might add. However, being used in a "basically" closed contaminated cooling system, with very slow evaporation possibilities ... prior to refilling, there could be a problem. At present, I am trying to locate a possible source on a local lake ( Lake Martin, near Alexander City, Alabama) and I will be sure to report my findings. Too bad I'm not down near the coast, where the bigger "industrial boats are).

As far as the Heater Core ... This definately demands further investigation!! Re-opening it, after a good cleaning, will only recontaminate the entire system as soon as it is filled and run. I will also report back on what I find on this "point".

One thing is for sure, I person will get a more truthful response from a forum of "users", that from a list of "providers". "Water in the Oil" is no where near the problem of "Oil in the Water" ... when it comes to a cure. Of course. this is only coming from one who was in the foreign car repair busines for 45+ years.
Again, I thank you all very much and hope you have a great Summer! I'll report on what I find.