D4-225 Power Problem

Went out for our first season outing. Was able to get up on plane only by increasing power 100 RPM at a time. On the way in, I was unable to get it up on plane so came in 1200 RPM. When changing the air filter, the turbo was checked and turned freely. That was a couple of months ago. This is the first time in the water since that time.

Also on the way in, while trying to get the RPM's up, the engine overheated. It is possible that this in unrelated to the power problem. We were fishing kelp and the intake could have gotten plugged. Although I raised the outdrive and saw nothing. I was thinking that the overheating was related, and ran in slow as a precaution.

Any ideas or suggestions? Bill

How do the fuel filters look. If it's been awhile since you ran it last, you could have a fuel breakdown going on in the tank. If the filters look like they have slime on them, get soom fuel stabilizer and a couple extra sets of filters or have a service polish the fuel.

Mike

Here is a good read to keep us all in the loop on the shelf life of diesel. found this on http://www.fourwinds-ii.com/v2/?c=li...gaeCauseEffect

Most people who operate and maintain Diesel engine systems are familiar with the black slimy material frequently seen in their fuel filter elements, and found in the bottoms of their fuel tanks. It is known by many names e.g. algae, mud, sludge, dirt, BS&W , and many other unsavory sounding terms - all of which are misnomers. Many people think this material is some sort of microbe, thus in the marine industry, it is most commonly called "algae". While bacteria and other microbes contribute to and accelerate this process, sludge is no more bacteria than milk that has turned into cottage cheese - it's still milk, only in a physically different form -- Diesel fuel forms wax and asphalt, not "algae".

To understand the source and nature of this material, it is helpful to know a little about how Diesel Fuel and other distillate products are made in today's modern refineries. In the "old days" (15 - 25 years ago) processing of crude oil into the light distillate products we all know as gasoline, Kerosene, home heating oil, jet fuel, and diesel was basically done through heating the crude oil. At different boiling points, the various fractions of the crude were evaporated then condensed and sent to a storage tank for distribution. The distillate product, diesel fuel included, were fairly stable products with shelf life measured in the several months range.

The residual oil left over after the distillation process, approximately 50% of the barrel of crude that we start with, is the very heavy oils that are used for large ships and power plants, along with other industrial applications e.g. manufacture of products such as plastics, pharmaceuticals, nylon, asphalt, etc.

The refining process is dramatically different today. Demand for these light distillate products has increased rapidly, forcing the refiners to find new ways to extract more of them from the crude oil. Catalytic, or chemical cracking now allows the refiner to make more of the valuable lighter distillates from each barrel of crude, leaving only about 16% of the residual as heavy fuel oils. Environmental concerns have resulted in additional treatment of diesel, for example to lower sulphur content. This also contributes to instability of today's fuels.

Diesel fuel refined with these new methods is far less stable than that made with simple distillation. This results in more rapid deterioration in the form of solids precipitating to make sludge. Key fuel components such as paraffins and asphaltenes begin to oxidize and re-polymerize resulting in dark coloration, clogged filters and tank sludge that is commonly called "algae". In reality, this stuff is actually wax and asphalt !!

When this condition is present, the fuel does not combust rapidly causing a loss of engine efficiency. When the exhaust ports open, still smoldering fuel clusters become smoke and soot, leaving carbon buildup in the engine and exhaust trunk. Eventually, when it precipitates to the bottom of the tank, or is trapped in your filter, these key components cannot contribute to transferring the energy in the fuel to power the engine.

So the cause of the so called "algae" is simply the result of ageing fuel, which can occur in as little as 60-90 days, and depending on the cleanliness, and maintenance of the tanks in which it is kept, possibly even sooner.

The results of using fuel in this condition include
• Tank Sludge that must be removed manually or dissolved with chemicals
• Clogged filters that must be replaced(and disposed of)
• Incomplete combustion
• Wasted BTU's
• Smoking engines
• Carbon Deposits in the engine
• Shortening the life of major (read expensive) engine components
• Dirty engine Oil
• Poor engine performance

Solutions for Recovering Diesel Fuel Quality
Traditional technologies used to protect engines from poor quality fuel include filtration to remove particulate e.g. dirt and sludge, separation of water content, and use of biocides to control microbial activity, which can contribute to more rapid formation of solids. Equipment to provide this protection is of course, still necessary. However, what many operators are seeing is a much shorter life of the filter elements, resulting in more frequent filter changes. This is due to the paraffins and asphaltenes (and other fuel components) having re-polymerized, or agglomerated to form solids. This will happen even without the presence of microbes, so biocides cannot prevent this problem from occurring.

Summary
Today's Diesel Fuel is refined in a much different way than that of 15-20 years ago. Catalytic cracking produces a far greater volume of light and middle distillate products from each barrel of crude oil, however the stability of the fuels has been dramatically shortened.

Key fuel components such as paraffins and asphaltenes begin to form clusters that precipitate into the sludge commonly known as "algae". They comprise the bulk of this material that clogs filters, causes engines to smoke and perform poorly, and makes tank sludge.

Mike, Thank you for the information. I did change all the fuel filters as part of the maintenance routine. I will check them to see if the fuel has a problem. I have one of those Algae-X fuel conditioning systems. I don't know anything about the system, but I understand it helps. The fuel has been in the tank since October when I pulled the boat out of the water.

I am also going to pull off the exhaust elbow and make sure the turbo turns freely. What are the other possibles?

Your motor will electronically limit revs if there is a problem in the system; the sad part is you might need the Volvo Diagnostic Computer to plug in and read your ECU.
Also, I received a recall last week on the ECU unit; the motherboard can let circuits get loose. Steve told me to contact Nielsen/Beaumont, they are the only ones with the computer tester right now.

I have been in contact with Jay at Nielson. His Volvo mechanic is out with knee surgery for two weeks. I am on his schedule for the week of the 8th. I am sure you could meet with him when he visits J-dock. I wonder if that recall includes an older engine like mine?

Your's isn't THAT OLD!

With the problems I have been having, the engine (or perhaps me as a result) feels like it is old. Are boats always this much fun? Why didn't you guys warn me?

So maybe J dock has a two fer one D4 recall going?

As a followup to this post. A combination temperature/pressure sensor was replaced and everything works. According to the mechanic from NB, the temp sensor was reading very high and this would prevent the turbo from kicking in. The sensor has a thermistor for temperature. The defective one was reading over 200 degrees with the engine just started up. The new one 65. Having one of those Volvo handheld computers is the ticket to knowing what is wrong with the engine.