Because of coolant loss I was told my engine may have a leaking head gasket. Over time I tried adding stop leak and head gasket sealers.Finally I had the intake manifold gasket replaced. But now I still have a problem which might be due to clogged ports in the intake manifolds and/or the heads. The coolant steams from the overflow reservoir as the engine warms up and leaves a bad odor. I'm wondering if any of that Barrs stop leak material can be flushed out? The radiator is probably ok as it is fairly new.