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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 14175
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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Oone of my volvo D6 IPS500 engines displays about half turbo

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Oone of my volvo D6 IPS500 engines displays about half turbo presure in comparison to the port engine.

they are reguarly serviced - oil and coolant levels have been checked and are maintained

why is one turbo displaying at least half the presure from the other one


HI Lui,

My name is XXXXX XXXXX I will be helping you today. Does that engine run any differently, or put out more smoke than the opposite engine? The reason I ask is because if it does, then boost pressure really is low, but if it doesn't, then boost pressure is fine.

Customer: replied 2 years ago.

hi Jason


it does not put out more smoke.


the volvo engineer has put the diagnostics on it and it does not show any fault


he is suggesting that there is low compression pressure in the engine and as such the engine needs to be openned up. im not sure



Does the engine run fine? Does it make full power? Is there any black smoke?
Customer: replied 2 years ago.

the engine runs very well

it does not make full power in fact the boat is capable of 32knots but will only do approx 20knots


no black smoke

Has the mechanic measured the boost pressure manually yet, with a manual pressure gauge? Or pulled off the turbocharger and actually just looked at the turbine blades yet to see if they are carboned up?

Is the engine at a Volvo Penta dealership, or just an independent shop?

Customer: replied 2 years ago.

im not sure if the mechanic has measured the boost pressure yet - will check with him


the turbocharger has not been taken off and the turbine blades looked at to see if they are carboned up. if they are how do you sort this

1 more question. Do you happen to have the serial number for the engine. I want to check it for recall campaigns. There was 1 on the D6 family of engines that stands out, but I want to see if it applies to your specific engine or not.

Is this boat at a Volvo dealer, or just an idependent shop?

Customer: replied 2 years ago.

i dont have the serial number with me because the boat is in Vilamoura


the engineer servicing the engines and advising me is a Volvo registered service dealer.

Have your dealer run the serial number and see if there is any campaigns (recalls) in regards XXXXX XXXXX charge air pressure sensor. Some D6's did have recalls on these, others did not. But thats just for the recall. But here is how it all works. The engine does have what they call a charge air pressure sensor on it, this is what measures the boost pressure. This sensor is what feed information to the engines computer, and also the gauge that you look at. If the engine is not blowing black smoke, then it is more likely that boost pressure is actually fine, and it's just the charge air pressure sensor that is not reporting turbo pressure back to the engines computer. On these engines when boost pressure is low the engines will not have complete combustion, and it will blow black smoke like a 1960's diesel powered farm tractor. Does that make sense?

As far as how to procede here. There are a couple of ways to go about this. Because you have twin engines the easiest thing to do is just swap the charge air presssure sensors on the engine, and see if the problem follows the sensor to the other engine. If it does, it's just a bad sensor. No big deal and all you need is a new one. But if the problem stays on the same engine, then either boost pressure is low or there is another electrical problem going on. What would be done next is a mechanical boost pressure gauge gets plumbed into the manifold, and the engine run, and the pressure is checked manually. If it is low, the turbocharger comes off and inspected/rebuilt. If pressure is good, then your back to an electrical/sensor issue.

But given that there is no black smoke, honestly chances are it's just the charge air pressure sensor. They do go bad. And on alot of the D6's there was actually a recall on them.


Thats how I would handle this one here. If that makes sense to you, then that should do it here. And just let me know if the ratings box gives you any troubles or if you can not see it. (you should see the tab now). But, if you have a further question on this or need more detail, by all means feel free to ask before doing the ratings.

If I do not hear back from you thanks in advance and good luck!



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