V8-430-CE-D cooling issue

[sin7]

Hi, I have recently purchased a 2015 Cobalt 336 with twin VP 430 hp, the motors have had a cooling issue since day 1, First I replaced both impellers, they were toast when the dealer delivered the boat-that's another story. Cleaned out what pieces I could find in the lower hoses connected to the cooling tower, The boat will run at 160 degrees or cooler under 2300 rpm, as soon as you get up to 3100 rpm, cruising speed it will slowly rise until you throttle back down. Does anyone know if there is a secondary water pump for higher rpm other than the impellers? Any other ideas? Boat is still under warranty, bit its impossible to get service in MN from a Cobalt dealer that didn't sell me the boat. Dealer i bought from is 1500 miles away and has gotten anywhere with Cobalt of VP. Thank you in advance, Daniel

 

[Scott Danforth]

Its under warranty, that is the route you should go.

 

[sin7]

I agree, unfortunately that means waiting for the end of the season before I can get service, I would like to enjoy my purchase before the snow flies in MN. I think it is a simple fix, i am just looking for little direction to rule a few things out.

 

[muc]

Its under warranty, that is the route you should go.

Hi Daniel, Welcome to the forum.
I agree with Scott’s advice. But I will warn you that overheating issues are almost never covered by warranty. Also, you don’t need to go to a Cobalt dealer to get this covered under warranty (if it is something that’s covered) but you will need to go to an authorized Volvo Penta dealer. Volvo’s website has a dealer locator that will help you find one. It will probably be best to choose a dealer that is on the water so the boat can be troubleshoot and tested in the lake/river.
Taking your boat to a GOOD dealer ---- or having them come to you ----- will probably be best. But we will help if you want to attempt the repairs yourself.
I’m curious when you say “I think it is a simple fix” because Iv'e heard this from many customers over the years and the answer can sometimes greatly speed up diagnosis. So why do you think that?

If you want us to help you get this problem taken care of as cheaply and easily as possible we will need the answers to all of these questions.

1. What is your engine serial number?
2. Does this boat have joy stick steering?
3. Does this boat have sea strainers?
4. Does this boat have a neutral salt system or other engine flushing devise installed?
5. Can you get this boat out of the water and pull the drives if that’s what’s needed?

To answer the question you asked. “Does anyone know if there is a secondary water pump for higher rpm other than the impellers?” Yes there is, it’s called the circulation pump. But the symptoms you have described so far don’t point to this as being the problem.