Flush coolent/oil mix from crankshaft

[sadanyagci]

Hi. I have a Suzuki Forenza 2004 that blew its head gasket and leaked coolant into the oil. It blew the gasket because I kept having coolant leaks, which caused some overheating issues. I'm a novice with cars, but managed to take everything out except the engine body and crankshaft, and clean everything up.

The mechanic at the machine shop I took my head to for resurfacing told me to not bother with the hassle of taking the crankshaft out for cleaning, and instead to just do several oil changes after everything is back together, and that will clean the engine out. That was a relief to me, since taking out the crankshaft seemed like it would be quite difficult and easy to mess up, working alone like I am.

I'm trying to find if cleaning out the engine with oil changes like this is a good idea, and if so, how best to do it. The engine takes 5W-30. Should I use that to clean it out, or use 0W-20 since it has lower viscosity and might clear more out? Should I idle the engine with a flush additive before I drain it? Should I drain it hot? Should I use a specific type of oil? How long should I run it between changes and how many times should I change it? Any advice would be greatly appreciated.

 

[fdcg27]

You've not only got some leftover goo in the engine, you've also had it opened.
I'd do a couple of short drains, like maybe 500 miles each with any cheap oil and filter and call it good.
No need to go to extremes to clean out what'll get cleaned out anyway.
Any damage is already done, since coolant isn't friendly to bearings.

 

[pitzel]

If you go find my "40k OCI thread", you'll see pictures of the crankcase of an engine which was exposed to the coolant/oil mix from a leaking lower intake manifold gasket, and received 1 relatively short oil change to flush such out. It wasn't a big deal, and as the pictures indicate, there were no long-term deposits. One short interval with 5W-30 should be just fine.

 

[901Memphis]

I wouldn't be using a thinner oil, I'd just look at changing it more often to get the accumulated contamination out.

Most engines flushes create a high friction environment and even though they may remove some gunk they will create an exponentially higher amount of wear in a very short period of time.

There may be some good products out there, if I was going to experiment I would give Amsoil engine flush a try, since most all of their other products are top notch I'd hope that the flush was too.