KAMD 42 Overheating problem

"One of my KAMD42 engines with

"One of my KAMD42 engines with DP outdrive has been running slightly hotter than the other for a while but recently the problem has become worse. The VP agent has completely stripped, cleaned & re-installed the cooling system, with no improvement. Removing the thermostats improved the situation at low revs but at high revs the same problem persists. Comparing the two temp gauges, the needles increase at the same rate from starting but while one stops at around 90 degrees, the other keeps going. We have checked the intake and the hoses from the outdrive to the seawater pump. The impeller is fine. I am losing a small amount of water from the cooling system (not into the bilge). Any suggestions? The next possibility to check is the head gasket but before doing that I'd appreciate feedback on the chances that this might be the problem."

"Check the turbo, on mine was

"Check the turbo, on mine was cracked the case and the water was going out trhu the waste. Hope this help."

"Thanks, Alejandro. The head

"Thanks, Alejandro. The head has already been removed, there were faint traces of water leakage and there were some hairline cracks in the head near the valve seats. We put on a new head, gasket & seals but it did not solve the problem. We only did a short sea trial so I am not sure if I am still losing water but it is overheating. So, I will have the turbo checked at the same time as the heat exchanger is being re-checked. Any other suggestions would be most welcome - even the VP engineers are scratching their heads!"

"I have also had a heating pro

"I have also had a heating problem on a AD41 for years, I have taken every hose of and cleaned heat exch, oil cooler, replaced impeller pump, took apart outdrive to change sealings...but still problem not solved just slightly overheated when under long pressure. This year after Morten's advise I changed intake valve from drive to engine and at the same time I changed the rubber hose. I then noticed a big difference in that hose the old one was unessesary hard bent and almost became flat in the bend i suspect under hard underpressure it could colaps a little inwards and prevent enough water flowing (I saw another post where this had happened). Still this year water temp in Sweden is so low so not sure if problem is solved or not I will know for sure when water teamp reaches 20...But last weekend I did pressure her hard a and long in 15 degree water and she have never been running that coold (under 90 degr)."