Volvo D2-75 Turbo

[If only I had more speed]

Yes I did, the two main gaskets are metal sandwich type so they were cleaned and lightly coated with HT grease. The copper washers were annealed and the oil drain was just very lightly coated with HT grease.
I'm planning to make a connection to break into the air pressure line so I can get confirmation of normal readings and then to fit a high pressure alarm. Watch this space.
I am suspicious that I may have previously slightly twisted the spindle on the valve prior to the repair so I need that confirmation.

 

[John christman]

Caution to those with the turbo on the Volvo Penta D2-75!!! My waste-gate seized, I didn’t know it, and it blew the head gasket when I pushed the RPM’s to clean the carbon out. This obviously required a very expensive half rebuild. A new turbo was fitted and the waste gate failed again due to carbon buildup the following year again despite running the motet hard. Gave up on it, and I decided not to push the RPM’s so much so I wouldn’t over-boost again. Now carbon buildup has seized the turbo from the exhaust side and my second turbo is shot. Good luck getting any help from Volvo Penta. Clearly they have a problem with the turbo.

 

[Skylark]

Caution to those with the turbo on the Volvo Penta D2-75!!! My waste-gate seized, I didn’t know it, and it blew the head gasket when I pushed the RPM’s to clean the carbon out.
.............
Clearly they have a problem with the turbo.

Sorry to read this, John, but, with respect, I don’t see it as a problem with the turbo. The “effect” of the problem manifests as a blocked/seized wastegate but the “cause” is excessive carbon emission deposits. Unless the root cause of the problem is determined and rectified, you should expect to see a repeat failure in the fullness of time.

 

[If only I had more speed]

From what I have seen and read I believe that the D2-75 was a step too far for the Perkins based engine. I'm not sure about the rest of you but I purchased the Volvo as it had the best power to weight ratio of its class and was conventionally injected. Pushing the boundaries on power involves pushing up the MEP and stresses all of the engine internals including non moving combustion parts like head gaskets.
One of the other consequences of increased boost pressure can be an increase in blow by around the pistons. This blow by then leads to an increase in bore, piston and ring wear which further increases the blow by. Increased blow by increases the crankcase pressure and has to go somewhere so it leaves through the vent into the turbo inlet thus contaminating the incoming air charge and burning in the engine.
A consequence of marine engine water cooled manifolds is that the cooler exhaust gasses can deposit carbon easier and that is what we're having problems with in the Volvo designed inlet/outlet casing attached to a generic turbo.
If Volvo had placed the wastegate valve linkage on the top of said casing instead of burying it underneath it would probably never have been a problem as it would be clear of the moist gasses and condensation when the engine is started.
My solution is going to be removing and cleaning the turbo casing every season whilst the boat is up.

 

[Beneteau381]

The Perkins 400 series engine was developed to do a generic job. Volvo marinised it, ie painted it green! The turbo version will have been engineered to cope with the loads so the business of piston bypass? Sorry, wrong conclusion. The issue Is caused by the way we use them. The Perkins driving a generator would sit at near max revs with a good load on it. Fitted to plant Equip or such like, a similar scenario. The turbo would be spooled up, running at optimum temperature and running clean. Then we come to the way we use them. Low revs, or just above tick over whilst we “motor sail”. Running at low temperatures, The turbo hardly spinning in the great scheme of things. Carbon build up is inevitable. Did you know that Bukh recommend running their engines at max revs every hour of running! The carbon builds on the turbo blades quickly, they stick and the vicious circle continues. The waste gate seizes because they hardly ever operate, we don’t run them hard enough to generate enough boost to trigger them, plus as some have said there have been some faulty castings?
If any blame is to be attached, attach it to manufacturers who fit engines that are too big, we never use that excess power! That old chestnut about punching through seas in rough weather? If its that bad then slamming is what causes people to not use it!

 

[If only I had more speed]

Please take a look earlier in the thread regarding boost pressures and the wastegate operation. Please also note that the marinizing of the engine including the turbocharger is done by our friends at Volvo. However you are quite correct in saying that duty cycle does contrite to carbon build up. In this particular engine the problem has been exacerbated by poor design.

 

[Skylark]

I worked for a turbo manufacturer for 20 years, much of that as an application engineer responsible for matching product to OEM engines, including the Volvo Group

It's well worth Googling the reasons for excessive carbon build up in diesel engines. Should be helpful.

 

[Beneteau381]

Please take a look earlier in the thread regarding boost pressures and the wastegate operation. Please also note that the marinizing of the engine including the turbocharger is done by our friends at Volvo. However you are quite correct in saying that duty cycle does contrite to carbon build up. In this particular engine the problem has been exacerbated by poor design.

I would bet that the turbo pictured here on the Perkins base engine Perkins | 404D-22TA
is a Garrett core and that it is the same one that VP bolt on to their inter cooler exhaust system here D2-75 | Volvo Penta
They have form on this, the MG Maestro turbo engine that I stripped and rebuilt as a project and spare engine for my MD22 is a base Perkins Prima 50, modified by VP to form the MD22 series, the turbo was a Garrett core, exactly the same as my mates TAMD 22 but with modified end castings to suit the exhaust orientation. I could almost guarantee that that is what they have done here and could perhaps explain the waste gate casting faults.

 

[Beneteau381]

I worked for a turbo manufacturer for 20 years, much of that as an application engineer responsible for matching product to OEM engines, including the Volvo Group

It's well worth Googling the reasons for excessive carbon build up in diesel engines. Should be helpful.

Is that you David?
Stu

 

[Skylark]

Is that you David?
Stu

Yes. How are you both doing, hope all is well?

 

[Beneteau381]

Yes. How are you both doing, hope all is well?
[/QUOTE
Still here, champing at the bit, boat in Albufeira, lucky some mates are there to keep an eye on.

 

[John christman]

I would bet that the turbo pictured here on the Perkins base engine Perkins | 404D-22TA
is a Garrett core and that it is the same one that VP bolt on to their inter cooler exhaust system here D2-75 | Volvo Penta
They have form on this, the MG Maestro turbo engine that I stripped and rebuilt as a project and spare engine for my MD22 is a base Perkins Prima 50, modified by VP to form the MD22 series, the turbo was a Garrett core, exactly the same as my mates TAMD 22 but with modified end castings to suit the exhaust orientation. I could almost guarantee that that is what they have done here and could perhaps explain the waste gate casting faults.

Sorry to read this, John, but, with respect, I don’t see it as a problem with the turbo. The “effect” of the problem manifests as a blocked/seized wastegate but the “cause” is excessive carbon emission deposits. Unless the root cause of the problem is determined and rectified, you should expect to see a repeat failure in the fullness of time.

I’m almost positive that the waste gate didn’t originally seize due to excessive carbon buildup. When I inspected the turbo after I over-boosted, and blew the head, it was rather clean but sealed shut. Thereafter, I was petrified, and still am, to run the motor at WOT in fear of another 7,000 dollar rebuild if the waste gate failed to decide to open one day. Running on low RPm’s has agreeably now caused my second failure of waste gate and seizure of blades due to carbon buildup. You know these turbos aren’t cheep..... I think I may have to do the same, take it off each year, make sure the waste gate works, clean it, and run the motor hard with fingers crossed!!

 

[Beneteau381]

A

I’m almost positive that the waste gate didn’t originally seize due to excessive carbon buildup. When I inspected the turbo after I over-boosted, and blew the head, it was rather clean but sealed shut. Thereafter, I was petrified, and still am, to run the motor at WOT in fear of another 7,000 dollar rebuild if the waste gate failed to decide to open one day. Running on low RPm’s has agreeably now caused my second failure of waste gate and seizure of blades due to carbon buildup. You know these turbos aren’t cheep..... I think I may have to do the same, take it off each year, make sure the waste gate works, clean it, and run the motor hard with fingers crossed!!

quick finger check every so often would confirm that the wastegate is operating

 

[Beneteau381]

I’m almost positive that the waste gate didn’t originally seize due to excessive carbon buildup. When I inspected the turbo after I over-boosted, and blew the head, it was rather clean but sealed shut. Thereafter, I was petrified, and still am, to run the motor at WOT in fear of another 7,000 dollar rebuild if the waste gate failed to decide to open one day. Running on low RPm’s has agreeably now caused my second failure of waste gate and seizure of blades due to carbon buildup. You know these turbos aren’t cheep..... I think I may have to do the same, take it off each year, make sure the waste gate works, clean it, and run the motor hard with fingers crossed!!

The mate of with the TAMD22 actually brought his seized turbo home from Spain to the UK as hand luggage. His wife cleaned the carbon out of the blades etc with small picks etc, then a good cleaning with petrol got it like new and it worked fine when he refitted it. so it’s not an issue to mechanically clean the carbon off. I have found one of your compatriots on Youtube who uses Chemclean to clean carbon off a cylinder head

perhaps a yearly clean wouldn’t go amiss? A finger check that the wastegate is operating, with a pressure guage on the manifold to check that you aren’t overboosting and a WOT now and again would be an easier option. It ain’t rocket science!

 

[Kuno]

We have the same issue with our D2-75F. The wastegate was stuck from almost new. The resulting high pressure then pushes the hose clamp on the soft connection after the turbo up and releases the pressure. I used to run the engine at 1800 rpm which is 6.5 to 7 kn and very little noise and vibration. But with the over cooling in the exhaust elbow it creates a lot of carbon buildup and corrosion in the elbow. Last fall the turbo actually seized up with carbon deposits. I managed to free it up and install a new Stainless steel elbow this summer. The engine runs fine now and we run it at 2000 to 2100 rpm which seems to be ok except more fuel and noise.
I installed a Pressure gauge after the turbo. The turbo only starts to produce charge at 1800 rpm 1psi, at 2000 rpm 3psi, 2200 rpm 5psi, 2400 rpm 7psi, 2600 10psi,
Since I could not free up the waste gate to move freely I will only run the engine to 2600rpm under load.
The waste gate is so poorly designed that I'm convinced that non of those engines have functioning waste gates. I think replacing the elbow with stainless steel is a smart move, other people on this forum had to cut the elbow out with a grinder because of excessive corrosion. One bolt on our engine was almost rusted in place. I was lucky to get it out whit out breaking the bolt off. The engine is only three years old.
I ordered the elbow from www.parts4engines.com for 400 British pound .
If we still have trouble with the turbo I will convert the engine to a D2-55. All I have to do is take the turbo out and buy a different elbow. When the turbo was seized we still could get to 2600 rpm and 8.2kn speed, that's good enough for me.

 

[John christman]

We have the same issue with our D2-75F. The wastegate was stuck from almost new. The resulting high pressure then pushes the hose clamp on the soft connection after the turbo up and releases the pressure. I used to run the engine at 1800 rpm which is 6.5 to 7 kn and very little noise and vibration. But with the over cooling in the exhaust elbow it creates a lot of carbon buildup and corrosion in the elbow. Last fall the turbo actually seized up with carbon deposits. I managed to free it up and install a new Stainless steel elbow this summer. The engine runs fine now and we run it at 2000 to 2100 rpm which seems to be ok except more fuel and noise.
I installed a Pressure gauge after the turbo. The turbo only starts to produce charge at 1800 rpm 1psi, at 2000 rpm 3psi, 2200 rpm 5psi, 2400 rpm 7psi, 2600 10psi,
Since I could not free up the waste gate to move freely I will only run the engine to 2600rpm under load.
The waste gate is so poorly designed that I'm convinced that non of those engines have functioning waste gates. I think replacing the elbow with stainless steel is a smart move, other people on this forum had to cut the elbow out with a grinder because of excessive corrosion. One bolt on our engine was almost rusted in place. I was lucky to get it out whit out breaking the bolt off. The engine is only three years old.
I ordered the elbow from www.parts4engines.com for 400 British pound .
If we still have trouble with the turbo I will convert the engine to a D2-55. All I have to do is take the turbo out and buy a different elbow. When the turbo was seized we still could get to 2600 rpm and 8.2kn speed, that's good enough for me.

Sorry you are having this problem as well. It is very frustrating. Thought of the same solution but I really wanted a 75 HP motor!! If you remove turbo you will blow black smoke at higher RPMs.

 

[Ring of fire]

Immediately after fitting a new turbo and cleaning the intercooler oil still came from the weep hole. It produces oil all the time. So much so it gathers on the underside of the engine. Increasingly I agree with the view that the turbo itself is not the cause of the problem. It’s failure is a symptom of an engine that is out of kilter.

Does anyone know what the correct compression pressure for this engine should be and what tolerances are allowed. The workshop manual implies a minimum of >27 bar at the starter motor.

 

[Skylark]

Immediately after fitting a new turbo and cleaning the intercooler oil still came from the weep hole. It produces oil all the time. So much so it gathers on the underside of the engine. Increasingly I agree with the view that the turbo itself is not the cause of the problem. It’s failure is a symptom of an engine that is out of kilter.

Does anyone know what the correct compression pressure for this engine should be and what tolerances are allowed. The workshop manual implies a minimum of >27 bar at the starter motor.

What does “out of kilter” mean?

I find it hard to comprehend that you appear to have a serious oil leak but have not done nothing about it ?

Here’s a spec sheet for the D2-75 and it shows a cylinder pressure of 29.5 bar at 248 rpm.

http://www.darthaven.co.uk/userfiles/products/files/Technical data D2-75.pdf

The turbo only starts to produce charge at 1800 rpm 1psi, at 2000 rpm 3psi, 2200 rpm 5psi, 2400 rpm 7psi, 2600 10psi,

Those results seem reasonably consistent with the spec.

The waste gate is so poorly designed that I'm convinced that non of those engines have functioning waste gates.

Simply not true. Literally millions have been made to the same or similar design. From your description, you appear to have a problem with coking and find it convenient to blame the turbo without recourse to root cause.

If we still have trouble with the turbo I will convert the engine to a D2-55. All I have to do is take the turbo out and buy a different elbow. When the turbo was seized we still could get to 2600 rpm and 8.2kn speed, that's good enough for me.

Good luck with that, especially if you think such action will solve a coking problem ?

 

[Ring of fire]

Thanks for the data sheet Skylark.
Are all the d2 75 rated the same or are there significant differences across the range? Also would you have any idea as to acceptable wear tolerances for the compression test. As for out of kilter - not functioning as it should.

Our engine started to produce oil / vapour from the condensate hole beneath the intercooler from almost new. Despite making VP aware of the problem it was thought that the wastegate was to blame and all too often engineers in the med would just wipe off the oil and say keep sailing. When the new turbo was fitted I expected things to improve. We have cleaned the crankcase breather valve, reduced the oil level had a back pressure and compression test by VP. Only one engineer said he thought the piston rings were the issue but even he said it’s just a bit of oil and that we should live with it. That same engineer was surprised by how much oil /vapour the intercooler weep hole produced with the breather pipe disconnected on trial. But the consistent line we are told in the med is to accept it and live with it. We have contacted other owners who see no oil at all. VP in the UK have said they find the whole thing a bit odd but it’s difficult for them to get involved. Our frustration is that you toe the line by adhering to the warranty and but spend every holiday in the company of an VP engineer.

 

[Skylark]

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.