I am reviving an old thread of mine, but thought providing closure would help provide a possible solution to someone with a similar problem. To summarize, I was having a steaming/white smoke issue during cruise and engine coolant temp was reaching its upper temp limit at WOT.
- I serviced the injectors, which did resolve the stinky fuel smell and slight diesel slick at start up. Still had steam though.
- I removed/cleaned the exchanger (no blockages) and flushed engine with Barnacle buster. No change in temperature and temp was 200 degree at WOT.
- Added a Volvo Penta expansion tank to increase coolant capacity and better monitor coolant. No difference.
- Double checked the through hull, rebuilt the Perko sea strainer, and inspected raw water hoses for any blockages. All good.
- Hull and running gear were clean.
- Replaced impeller.
The Volvo, cast iron high rise injection elbow was only three years old and I did open the service ports to clean out the carbon. I assumed all was good. I revisited the elbow and removed it for full inspection. Water flow was definitely being restricted--it was nasty inside even after cleaning via the inspection ports.
I reached out to National Marine Exhaust and had a high rise, stainless steel injection elbow fabricated to include fiberglass wrap. I installed the elbow and was pleased to see ZERO steam and coolant temps at around 170 or a little over after 10 minutes WOT in warm gulf waters.
I could kick myself for assuming the elbow was fine.