Volvo D2-75 Turbo

[Beneteau381]

It sounds as though local VP technicians are grasping at straws.

With a new turbo fitted, you expected things to improve.......but they didn’t, suggesting that there never was a turbo issue. How did they explain an issue with a wastegate manifesting itself as oil in the induction?

There are two pathways to put oil in the induction system. One is a leak in the oil seal on the turbo compressor side. Unlikely in my experience (20 years with turbos including around 15 of them being responsible for the business at Penta [but not for their bought-out engines]). It would be easy to see evidence on the backplate.

The other, more likely route, is from the blow-by recirculation system. Establishing the root cause would be by a series of tests.

By adhering to their warranty stipulations you have demonstrated good faith so it’s time for Penta to reciprocate. If you’re not happy, why not elevate the issue within Penta, consider writing to their Gothenburg headquarters to get their attention.

Good luck with it.

The biggest issue I found with VP, after helping an owner of a brand new aluminium French boat, is that you cannot get in direct contact with VP Sweden. They say that the main dealers are the first point of contact. Thats the way their syatem works. Not much good if the main dealers cant and couldnt fix the issue! After I got involved and started making noises all of a sudden two engineers pitched up from Sweden with a computer and oscilliscope. After two days they found what I had noticed on my std meter, a blip coming from the negative isolation relay. Once that was fixed all was ok! So to the OP, the main dealers first and if they cant fix it then an all out campaign to get VP attention through journalists.

 

[Ring of fire]

I hope it doesn’t come to that. After a four hour trip we looked inside the turbo from the air filter side to find oil making its way towards the air filter. The turbine side was apparently cleaned and freed up just four hours earlier but looks to be soothed though again I don’t know it this is normal. We had a compression test which came at 23 bar which is 20% down on the spec sheet.
When we refueled we also seemed to have consumed more than normal. Am assuming this and the state of the turbo are linked to the compression but don’t know technically what might be going on. To be fair I believe VP are now taking this seriously which is good news. Any further pointers would be well received.

 

[Skylark]

Soot on the turbine wheel, especially after such low hours run, indicates poor combustion. Seemingly, not enough oxygen to completely burn the fuel. Put another way, too much fuel for the available oxygen. I have no experience of this engine and what inputs to the fuel injection system are required to deliver fuel under varying conditions of load and speed.

A stuck open wastegate valve would give insufficient low engine speed boost pressure (oxygen for combustion). What do you mean when you say that the turbine side was cleaned and freed-up?

Oil inside the compressor stage, as I've written earlier, has two routes. One is that it is being pulled across the seal. There are different types of seal arrangement but it's probably a simple piston ring on the shaft. This will seal the bearing lubrication oil against a pressure gradient. If there is too high an oil pressure inside the bearing housing and/or a relatively low pressure in the compressor, it will leak. It does happen but not common, especially given that you've already changed the turbo and the problem exists.

Second, most likely culprit, is engine blowby. Somewhere, you'll find a pipe, may be solid or rubber hose, probably from the rocker cover to somewhere between the air filter and the compressor inlet (hose with clip on in your second picture?). No real short term harm in removing it while the engine is running to see if it's spitting oil (solid or gaseous). Some blowby is perfectly normal and is part of the emission control circuitry. Could be a red herring, hard to see the extent of compressor wheel oiling from your photo.

Good to read that your local VP people are taking the matter seriously.

 

[Ring of fire]

Interestingly we recently had a sea trial where the engineer removed the breather pipe from the rocker cover to the turbo. With it disconnected the condensate weep hole located on the underside of the intercooler just continued to produce oil as if it was still connected.

 

[Beneteau381]

I hope it doesn’t come to that. After a four hour trip we looked inside the turbo from the air filter side to find oil making its way towards the air filter. The turbine side was apparently cleaned and freed up just four hours earlier but looks to be soothed though again I don’t know it this is normal. We had a compression test which came at 23 bar which is 20% down on the spec sheet.
When we refueled we also seemed to have consumed more than normal. Am assuming this and the state of the turbo are linked to the compression but don’t know technically what might be going on. To be fair I believe VP are now taking this seriously which is good news. Any further pointers would be well received.

A compression test will be done at starter motor speed so the turbo will not be having any effect at that speed. Have you checked the boost pressure with the engine under load?

 

[Ring of fire]

Hi Beneteau 381, In short. No. But I’m hopefully that won’t be necessary. The compression test showed that we were significantly down on spec. The manual for the Perkins 400 series turbo which I believe is the same engine is quite specific in advising that a repair is needed if you come in below 24.5 bar. I’m hopeful that this info in conjunction with oil from the intercooler condensate weep hole, a sticking waste gate and actuator which seems to be fouling/ sooting up along with a higher than normal fuel consumption will be enough to justify overhauling this engine. My fingers are now crossed but I will keep the idea of the turbo boost test. Many thanks.

 

[Acapella]

I have a 2017 D2-75 in my Allures 45.9. A Volvo dealer in New Zealand replaced my exhaust mixer with a stainless version from Parts4engines earlier this year. They had to cut off the old mixer as the fixing bolts has siezed. The dealer told me that the turbo wastegate was siezed and that they had freed it up. I would like to see if my wastegate has siezed again but I am struggling to find/feel the actuator lever that others have referred to. Please would someone describe exactly where to find the lever with photos if possible. I am also experiencing small amounts of oil in the bilge after several hours running and I suspect the oil leak is coming from under the turbo although I cannot see or feel the breather hole that others have referred to. Access to the turbo is of course very poor.

Many thanks.

 

[Acapella]

I have now found what I think is the wastegate lever and rod. See attached photo. In terms of direction of rotation, does the actuator rod come further out of the turbo when boost pressure builds? Thus the brass lever would turn clockwise looking from above (top of photo)?

Many thanks again.

 

[Acapella]

I have now managed to turn the wastegate lever but it only turns through about 10 degrees. I am pretty sure that this is because the lever is hitting the exhaust mixer. I am assuming the wastegate lever should turn through more than 10 degrees. Does anyone know how far it should turn? Tomorrow's job is to remove the exhaust mixer and grind some metal off so that the lever can turn without catching the exhaust mixer. see photo.

Is it likely or possible that my oil leak is due to the wastegate not opening fully? I have only noticed the oil leak since the new stainless exhaust mixer was fitted so perhaps the old mixer was not interfering with the movement of the wastegate lever? any thoughts appreciated.

 

[Ring of fire]

Our VP engineer read this thread and thought the exhaust could be the problem. To be sure he checked by taking the boat out and at full throttle and used a feeler gauge to ensure that there was in fact a gap between the exhaust elbow and the spindle mechanism when the turbo was at max boost. Luckily there was. The stainless steel option looks a very good idea and I wish we had gone down this route. But before grinding that beautiful exhaust I would check the clearance. When you use the spanner to move the rod does it “spring” back into the closed position? There should be a definite spring- loaded return to the closed position. If not would indicate it’s stuck. If stuck “in” then this is bad for engine pressure. If out then a problem still but probably won’t over pressurize the engine. Is there oil in the turbo air filter side?

VP service bulletin says the arm should only be moved by 15 degrees max. I think this equates to about 4mm so not a lot but then it doesn’t need to open that much. Interestingly we recently had a back pressure test and with the spacer fitted between the turbo and exhaust the engineer was able to open the waste gate more that normal and see the power drop off. To see how far the arm is moving try marking the arm close to the wastegate with some pencil. If it opens you will see how far. Other advice we have received. Clean the crank case breather valve, and check that the oil level is only midway on the dipstick and definitely not to the top mark. Don’t clean the turbo with WD 40 as this dries sticky and attracts deposits.

One contributor on here, Skylark, posed the question as to how would Volvo explain a waste gate problem manifesting itself as oil in the induction. And it’s a very pertinent and succinct question. Please search out his comments and links to data sheets.

I would also recommend (and wish I had done it years earlier) a compression test. I’ve lost track of the money, time and ruined vacations spent in port in the company of VP engineers who have had a look and told me to “carry on sailing and it’s just a bit of oil”. The test costs a couple of hundred euros / pounds but instantly provides some hard data and only takes an hour or so. See also Perkins 400 series engine. I attach VP service bulletin and pic of our turbo / intercooler. Good luck

 

[Beneteau381]

Hi Beneteau 381, In short. No. But I’m hopefully that won’t be necessary. The compression test showed that we were significantly down on spec. The manual for the Perkins 400 series turbo which I believe is the same engine is quite specific in advising that a repair is needed if you come in below 24.5 bar. I’m hopeful that this info in conjunction with oil from the intercooler condensate weep hole, a sticking waste gate and actuator which seems to be fouling/ sooting up along with a higher than normal fuel consumption will be enough to justify overhauling this engine. My fingers are now crossed but I will keep the idea of the turbo boost test. Many thanks.

You are quite right, the engines are based on the Perkins 400 series. Valves can also be the cause of low compression. I have found that on the MD 20X0 series engines, the back cylinders are susceptible to seawater intrusion from borderline exhaust raw water system installations. The back cylinder exhaust valve starts to get a pitted face, allowing poor compression and poor combustion. The poor combustion allows a build up of "wet" carbon. The point I am making, its not just bad piston rings that can cause these issues, could poor combustion and a bad exhaust valve be allowing unburnt fuel to run back through the turbo?

 

[Acapella]

Our VP engineer read this thread and thought the exhaust could be the problem. To be sure he checked by taking the boat out and at full throttle and used a feeler gauge to ensure that there was in fact a gap between the exhaust elbow and the spindle mechanism when the turbo was at max boost. Luckily there was. The stainless steel option looks a very good idea and I wish we had gone down this route. But before grinding that beautiful exhaust I would check the clearance. When you use the spanner to move the rod does it “spring” back into the closed position? There should be a definite spring- loaded return to the closed position. If not would indicate it’s stuck. If stuck “in” then this is bad for engine pressure. If out then a problem still but probably won’t over pressurize the engine. Is there oil in the turbo air filter side?

VP service bulletin says the arm should only be moved by 15 degrees max. I think this equates to about 4mm so not a lot but then it doesn’t need to open that much. Interestingly we recently had a back pressure test and with the spacer fitted between the turbo and exhaust the engineer was able to open the waste gate more that normal and see the power drop off. To see how far the arm is moving try marking the arm close to the wastegate with some pencil. If it opens you will see how far. Other advice we have received. Clean the crank case breather valve, and check that the oil level is only midway on the dipstick and definitely not to the top mark. Don’t clean the turbo with WD 40 as this dries sticky and attracts deposits.

One contributor on here, Skylark, posed the question as to how would Volvo explain a waste gate problem manifesting itself as oil in the induction. And it’s a very pertinent and succinct question. Please search out his comments and links to data sheets.

I would also recommend (and wish I had done it years earlier) a compression test. I’ve lost track of the money, time and ruined vacations spent in port in the company of VP engineers who have had a look and told me to “carry on sailing and it’s just a bit of oil”. The test costs a couple of hundred euros / pounds but instantly provides some hard data and only takes an hour or so. See also Perkins 400 series engine. I attach VP service bulletin and pic of our turbo / intercooler. Good luck

ire

Our VP engineer read this thread and thought the exhaust could be the problem. To be sure he checked by taking the boat out and at full throttle and used a feeler gauge to ensure that there was in fact a gap between the exhaust elbow and the spindle mechanism when the turbo was at max boost. Luckily there was. The stainless steel option looks a very good idea and I wish we had gone down this route. But before grinding that beautiful exhaust I would check the clearance. When you use the spanner to move the rod does it “spring” back into the closed position? There should be a definite spring- loaded return to the closed position. If not would indicate it’s stuck. If stuck “in” then this is bad for engine pressure. If out then a problem still but probably won’t over pressurize the engine. Is there oil in the turbo air filter side?

VP service bulletin says the arm should only be moved by 15 degrees max. I think this equates to about 4mm so not a lot but then it doesn’t need to open that much. Interestingly we recently had a back pressure test and with the spacer fitted between the turbo and exhaust the engineer was able to open the waste gate more that normal and see the power drop off. To see how far the arm is moving try marking the arm close to the wastegate with some pencil. If it opens you will see how far. Other advice we have received. Clean the crank case breather valve, and check that the oil level is only midway on the dipstick and definitely not to the top mark. Don’t clean the turbo with WD 40 as this dries sticky and attracts deposits.

One contributor on here, Skylark, posed the question as to how would Volvo explain a waste gate problem manifesting itself as oil in the induction. And it’s a very pertinent and succinct question. Please search out his comments and links to data sheets.

I would also recommend (and wish I had done it years earlier) a compression test. I’ve lost track of the money, time and ruined vacations spent in port in the company of VP engineers who have had a look and told me to “carry on sailing and it’s just a bit of oil”. The test costs a couple of hundred euros / pounds but instantly provides some hard data and only takes an hour or so. See also Perkins 400 series engine. I attach VP service bulletin and pic of our turbo / intercooler. Good luck

Hi Ring of Fire

Many thanks for your response and attachments.

Today I removed the exhaust elbow and confirmed that it was restricting the rotation of the wastegate cam. I ground a little metal off one corner of the exhaust mixer and the wastegate now rotates freely through about 30 degrees and springs back when released. All back together now and engine seems fine. I will need to test the wastegate opening when at sea and with engine under load. I have not done a compression test but will do when back in the UK next year. I did have an oil analysis done earlier this year and that came back fine. See attached photos.

 

[If only I had more speed]

Following on from my opinions posted earlier I've continued with the theory that the exhaust outlet is over cooling the wastegate area and allowing carbon to deposit along with occasional condensation when the engine is cold. I have fitted a custom made hot exhaust outlet elbow which has the water injection at a lower point. The results have been amazing so far, there hasn't been any sign of spindle tightness hot or cold yet this season. I will post more later in the year when the boat comes up for winter and I open up the exhaust.

 

[Ring of fire]

Does anyone have contact details of anyone in authority at Gothenburg HQ.

 

[Seahorse7101]

Following on from my opinions posted earlier I've continued with the theory that the exhaust outlet is over cooling the wastegate area and allowing carbon to deposit along with occasional condensation when the engine is cold. I have fitted a custom made hot exhaust outlet elbow which has the water injection at a lower point. The results have been amazing so far, there hasn't been any sign of spindle tightness hot or cold yet this season. I will post more later in the year when the boat comes up for winter and I open up the exhaust.

Hi - how is the new modification going? I was the person that started this thread several years ago! Although I have managed to stop carbon build up in the turbo/waste gate area by running the engine at higher revs etc, I am still struggling to stop the tightening up of the waste gate spindle. I have used high temperature spray lubricant to free it up but doesn’t seem to last.

 

[Brad R]

Hi all. I have a Tresfjord 28 with a d2 75. 150 hrs. Yesterday I found it would only turn up 2600 rpm. With the accompanying black smoke. Just went back in the water after a winter of maintenance. I removed the turbo and yes carboned up and stuck wastegate. Ordered up a new one from a place in Sweden. Any suggestions out there on how to minimize the carbon build up? Boat runs so nice at 2400 turns. Hate to run it faster as the stern squats to much. Any good fuel additives that may help?

 

[Tranona]

Reduce the size of the propeller so that it runs at the higher recommended revs for the same speed. Overpropping is one of the causes of excessive deposit build up in the exhaust.

 

[Beneteau381]

Hi all. I have a Tresfjord 28 with a d2 75. 150 hrs. Yesterday I found it would only turn up 2600 rpm. With the accompanying black smoke. Just went back in the water after a winter of maintenance. I removed the turbo and yes carboned up and stuck wastegate. Ordered up a new one from a place in Sweden. Any suggestions out there on how to minimize the carbon build up? Boat runs so nice at 2400 turns. Hate to run it faster as the stern squats to much. Any good fuel additives that may help?View attachment 153678

As @Tranona says but why buy a new one? Just carefully clean off the carbon and free the waste gate