When we bought our 2005 V258, 5.7 Volvo Penta, the dealer installed a closed cooling system. Our first time out it overheated, the dealer said air bubbles but our marina manager said he'd seen this before and to rev it up. That worked, he said it took a lot to fill the manifolds. The dealer replaced the temp sensors and the impellor and got it to "draw" at idle, but I've always reved it up just in case. The impellor was replaced by an independant shop (now out of business) a couple of years ago and I just replaced it today. Turns out, the extra I bought 4 years ago and the replacement I bought for today were too big. I got them at a Volvo Penta supplier in Seattle and went back with the part I pulled and and he exchanged them, finding one on the shelf that was the right size. Our Four Winns dealer went out of business, (Kurt the service manager kinda guided me in maintenance), so there's not a big presence here. My questions: Why is the part called out by Volvo Penta not the one I should use? I wonder if next time I should replace the entire pump assembly which would be "wider", but would there be a part that lines up with the bolt pattern? Also, there might be an issue with the metal brace fitting a new pump housing. Has anybody any experience with this? I'm going into my fifth year of boating and am really concentrating on getting to understand my boat. Thanks, Kevin
