Heat Exchanger Cleaning

[Martin610]

Greetings,

Just came up to ten years on my 2013 CW 28 with Volvo D4-260. It's running well. My mechanic is advising me to have the heat exchanger cleaned and recommends removing it so it can be "rodded out". He doesn't think barnacle buster is effective.

On the D4, removing the heat exchanger is a lot of work. I see one reference from Volvo where it seems to recommend cleaning in place.

I'm looking for input from others who have been down this road.

Thanks,

-martin610

 

[BB marine]

Your marine technician is probably correct on a 10 year old engine. Barnacle buster works but it does not replace o-rings and clean metal to metal services that can have corrosion. It also does not pressure check the system for leaks. Barnacle buster is a good product that should be used every couple of seasons to remove deposits before the deposits completely block a cooling tube. Once a cooling tube is completely blocked I don't think the barnacle buster is going to clean it. It needs to be circulating through in order to work. Barnacle buster is a good preventative item but doesn't replace doing a good maintenance repair to the exchanger and after cooler. My opinion!

 

[Martin610]

Thanks Brian, good advice as always. The boat yard is working up a quote for me now.

-martin610

 

[Martin610]

I just got the boat back from service. I'm very glad I took it in when I did. The boat was running well, no overheating. While the exchanger "wasn't terrible" in the words of my mechanic the O rings were "weeping" and I had some corrosion. The job required extra time to get everything apart. This particular shop uses a sonic cleaning process. This is supposed to be easier on the metal and possibly more effective. They repainted everything before re-installing. They cleaned my bilge compartment too. Engine looks new.

They wouldn't give me back the boat until the mechanic and I took for a drive together. I appreciate that. Other mechanics around here don't do that.

In my opinion this engine can last a long time if maintained properly. My understanding is that D4/D6 engines have cylinder linings in the case it has to be rebuilt. Marinized car engines are often a throw away.

-martin610

 

[BB marine]

It is my under standing that saltwater use of the D3, D4, and D6. O-ring seals are the weak link exchanger shell to exchanger bundle. When the O-ring starts to fail the leak is small and normally sealed from corrosion buildup. Eventually there is a failure. Loss of antifreeze is one indicator. The issue with D3, D4, D6, If this happens at the after cooler there is a possibility of sea water entering the air induction. Not Good! I have talked to techs that feel the integrity of the exchangers is increased after a full disassembly and cleaning is done. During reassembly anticorrosive grease is used and the o-ring sealing service is better than original.

In my opinion this engine can last a long time if maintained properly. My understanding is that D4/D6 engines have cylinder linings in the case it has to be rebuilt. Marinized car engines are often a throw away.

I agree with this statement 99.9% The .1 the D4 and D6 are "Parent bore" not sleeved blocks. Most of the smaller recreational displacement diesels are not sleeved. Cummins B 5.9, 6.7, Cat engines, 3208, 3116, 3126, the LP Series Yanmars, 6LY-2 Yanmar. Just to name a few good marine engines. None of these are throw aways. All can be rebuilt by boring and larger pistons installed. Some of them can be bored and dry sleeves pressed in the bores.In most cases the can be rebuilt with a honing and original sized pistons installed. The key is good maintenance. The D4 and D6 are in the same group well made marine engines built to run for thousands of hours. I have always compared the 5.9 and 6.7 cummins to the D6 Volvo and the D4 Volvo to 4LHA Yanmar made to run for years and hours. The D3 is a marnized engine that can be rebuilt but probably not cost effective probably would fall into a throw away. If well maintained and operated properly it could make 4000 hours. That is a life time of boating for most!