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Volvo D4 300

Discussion in 'Engines' started by rbradbury, Aug 12, 2020.

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  1. rbradbury

    rbradbury New Member

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    My Beneteau ST44 has started having overheat issues above 2500rpm. It's a 2013 model with 900 engine hours. Raw water strainers clear, just ran Barnacle Buster, bottom clean, etc. Local tech says I need to change intake and raw water sea cock to larger size. Beneteau has made hundreds of these, same engines, and I assume they know how to engineer the cooling system. Any thoughts?
  2. cleanslate

    cleanslate Senior Member

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    Call the service company back and tell them you want the A-Team not the B -team to come to your boat!

    Or look around for a different Volvo service company . You do not need to change the sea cocks and strainers that’s for sure!

    Make sure they’ve changed out all impellers , even if they look good.
    pull the hoses off where they can on the various oil coolers to check for debris in the coolers and heat exchangers.

    check the raw water intake strainer or clamshell on the bottom of the boat for sea weed and debris short haul the boat or get a diver to do that.
  3. rbradbury

    rbradbury New Member

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    Thanks for your thoughts on this. What is frustrating is that we have done everything you mentioned except get a different engine expert aboard. That's next, I guess.
  4. cleanslate

    cleanslate Senior Member

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    If the heat exchangers can come out those should be pulled and take it to a shop and be cleaned out a good radiator shop can do that.

    But otherwise I really don’t know Volvos very well.

    Perhaps some others will chime in that really know your motors.
  5. Pascal

    Pascal Senior Member

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    The suggestion to replace the strainer and sea cock is a joke. A cash cow of a joke for the con man suggesting it... but a joke.

    Engine manufacturers specify the size of all components incl intake cooling water, fuel lines and exhaust. I doubt Beneteau messed with that ... all warranty claims would be void

    As mentioned above make sure the intake clamshell is clean. Some divers miss them...

    What about the raw water impeller? Checked? Replaced ? Have you checked the inlet of the heat exchanger for impeller bits that previous mechanics were too lazy to find? Barnacle buster isn’t going to clear them.

    ado make sure you have to restrictions around the fuel and gear cooler. I ve seen this happen in the past not on Volvos but other engines

    how hot does it get at cruise and on the pins ?

    have you compared the outflow with the other engine? That’s the first sign of a restriction.
  6. T.K.

    T.K. Senior Member

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    Overheating at a higher engine speed is a very common issue in D4 engines of that age. The heat exchanger and intercooler become partially blocked with salt deposits and scale reducing the cooling effect. Coolant temperatures rise at a higher engine rpm and as soon as the engine speed is reduced, the engine coolant temperature drops back to normal levels. There is no need to remove the heat exchanger and intercooler to clean them. Simply carry out a 3 to 4 hour chemical flush procedure of the complete sea water cooling circuit using a marine descaler. It will clean the entire system and the the engine will regain 100% cooling efficiency. Remove all the engine pencil zinc anodes and the sea water pump impeller before carrying out the chemical flush.
  7. Liam

    Liam Senior Member

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    I had a client with a similar symptom on a D4 260hp. Oveaheating at above 3000 rpm.
    After he cleaned the heat exchangers, and changed impellers (a very useless move) since an Imp or works or it does not. No middle ground.
    Result was he had a fail exhaust manifold, which then failed and caused even further problem, including cracking a valve sleeve in the head.
    Check Impellers, clean heat exchangers but if symptom continue, do not move and test the exhaust manifold ASAP, for failure before it is too late.

    The manifold failure is a common issue with early Volvo D4 - D6 engines era 2005-10 seemingly effecting about 10% of the engines.
  8. Pascal

    Pascal Senior Member

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    i m not sure I agree with this. Everytime I had to change an impeller I was getting various red flags telling me the impeller needed attention. On generators it s a louder exhaust and a little bit of steam under load. On mains, it s usually higher coolant temps but often before coolant starts creeping up it is the gear which starts waving a big red flag with higher temp.

    plenty of warning that an impeller needs attention
  9. d_meister

    d_meister Senior Member

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    That's what I thought until I had an issue with 3406 Cats that were overheating and distorting the fiberglass exhaust tubes. The engine temps never came up under normal operation, but the exhaust tubes kept distorting and leaking water at the silicone hose. Finally found that the impeller vanes had taken a "set" in the direction of rotation to the extent that the vanes had no tension or wiping pressure action in the bore of the pump. Every vane was there and looked to be in good condition, but instead of sticking straight out when the impeller was out, they were curled over.
  10. cleanslate

    cleanslate Senior Member

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    Ahh! The dreaded impeller dysfunction , better known as I.D.
    I hate when that happens !
  11. Pascal

    Pascal Senior Member

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    So it was still working enough to cool the engines but sending warning signs. That was my point.

    were there SS crush sleeves where the hoses are clamped you the fiberglass tubes? Common issue on many boats. Crank up the T clamp a little too much and they distort and crack. Sometimes well after install.
  12. d_meister

    d_meister Senior Member

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    No, no SS liners, and what you say is what happened. A little drool at the silicone hose, and snug up the T-clamps, then OK for a while. "E" engines, and no alarms, no overheat, just no water flow out of the top of the spray ring.
  13. Pascal

    Pascal Senior Member

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    Yep. You need SS sleeves in there. When I repowered my 53 and redid the exhaust I made sure they put sleeves at every hose/fiberglass joint.