Oil Changes and Diesel Engines

"oil in the radiator ..." - head gasket gone (probably).

If, by overgauge you mean overfill the crankcase, this can cause damage.

If the crankshaft comes in contact with the oil, the oil will foam.

Multiply the number of cylinders X engine rpm and you will have that many oil/crankshaft contacts per minute. This could make a lot of foam.

Stationary engines are not as prone to this problem, since there are no G forces pushing the oil back and forth in the crankcase.

If you mean something else, never mind.

Inadequate training of maintenance personnel resulting in radiator being filled with oil instead of water. As stupid as it sounds, things like this happen sometimes.

The oil level in an engine must be maintained between the minimum and maximum gauge level on your dipstick. Both overfilling and running under the minimumm create problems for the longivitey of the engine.

Over-filling an engine with oil makes for a condition known as oil foaming - commonly seen with excessive oil weeping from the breater pipe, it can also create vibrations and lead to cracking of housings due to the pounding from the crankshaft into the surface of the oil in the sump.

Is the overfilling and oil in water symptons on the same engine.

If so my advice is you have a problem in your oil cooler, when the engine runs the oil pressure will force oil into the cooling system - oil in water, and when you shut down the residual pressure in the cooling system will force water back into the oil sump - creating an indication of overfull or above the mark.

It is not good to over fill an engine oil. The maker did a lot of work to decide what the optimum amount of oil would be for the design and it was marked on the dip stick to avoid any confusion.

If the engine is in a ship or boat the rocking and rolling can make it difficult to estimate where the correct level is. In this case the engine stopped, drained, the correct measured amount is then inserted and allowed to settle before the engine is restarted. To much oil is worse than not quite enough.

Oil in the cooling system is not good. It indicates a leak between the lubricating system and the cooling system. Unless you have an operator problem and they have placed oil in the wrong spot.

Some older engines use to use a soluble oil in the cooling system to prevent corrosion but that is rare these days.

BAB

As other posters have written overfilling the engine is counter productive. Sometimes though the dip stick may be cut too long, if you notice one gallon or half a gallon burning off soon after a service then holding steady for a third of the service period the stick might be too long. I usually run a diesel at one half gallon less than the dipstick indicates as full.

On new engines overfilling can contribute to wet stacking; oil being sucked into the combustion chamber then blown up the exhaust stack

To clarify, don't automatically underfill an engine. Fill to the line and monitor. If, as stated, a small quantity of oil 'burns off' quickly and then the level stabilizes, you are only wasting that amount of oil when you change. Mark that level on the dipstick, and if it stabilizes at that point every time then you can cut back on oil, but only to that level.

As has been said, the engineers carefully calculate the optimum oil levels, but the folks who manufactured and assembled the dipstick and tube may not be so precise.

"As other posters have written overfilling the engine is counter productive. Sometimes though the dip stick may be cut too long, if you notice one gallon or half a gallon burning off soon after a service then holding steady for a third of the service period the stick might be too long. I usually run a diesel at one half gallon less than the dipstick indicates as full."

In reference to the over filling the oil in industrial diesel engines, there is a lot of oil level tolerance built in when designing the engins. The engin is designed to operate at a 45 degree angel all dirctions with the oil below the add mark. Think of a small bulldozer going up or down hills or when you see someone with their Jeep out playing, trying to climb up a clif. I would be more concerned about the low mark even though I have seen many cars come in with no oil showing on the dipstick. If you overfilled the crankcase by 1/2 inch I would not try to drain it out, it's not that big of a deal.

Mike

true and if you do overfill extremely the resultant internal crankcase pressure should crack the fiberglass oil pan or blow out the plug at the rear of the camshaft before damaging the engine

Hi,

As suggested by others there is a major fault within the engine and to avoid serious damage to bearings thru' the possibilty that 'ere long the process will reverse and water enters the sump whilst the engine is at rest you should get the top off asap and see whether the head gasket is faulty. As you don't say anything about pressurisation or boiling it sounds as if the leak is from an oil way drilling to a water space opening, or similar location where oil pressure exceeds water pressure; otherwise there would be evidence of products of combustion in the header tank. Your nose is the best test for that scenario. The other areas of concern are as described by other contributors.

As far as overfilling is concerned the effect is for the windage within the crankcase to throw large quantities of oil at the bores which overloads the scraper rings and leads to high oil consumption and possibly blue smoke off the exhaust in extreme conditions.

Given your circumstances drain the sump and watch for water emerging as the drain plug is eased out of its threads ,that will show that you have ''two way traffic'' at the site of the fault. You might also find that you collect rather more ''oil'' than should be in the engine. QED

Whatever you think of doing don't run it again until its fixed!

Small crack in oil cooler most likely cause. Bad head gasket normally leaks water to outside also, and if oil leaks to water from bad head gasket, water will likely leak back to oil (not always) when the unit is stopped and the oil pressure goes down but the pressure inside the radiator (about 1/2 - 1 barg possibly) forces water through the same void backwards into the oil until it cools down. Head gaskets tend to have 'soft' spot failures that transfer combustion gasses and liquids into the radiator. Look for gas bubbles in the open radiator (open it while cool, then start and run under full load looking for tremendous violent amount of gasses from combustion leaking into water).

The oil would look like white milk if a lot of water is in the oil.

Oil coolers tend to have 'hard' spot failures, like a small crack, where it takes a lot of pressure (oil pressure at 3-4 barg) to open up the crack, but, when the engine stops, the crack seals itself and won't let water come in backwards.

If you have water and oil both mixed in crankcase and radiator then head gasket might be first choice, cooler second choice.

Over gauging: Everyone warns of foaming which is true, like dishwasher action and the oil blows out past the oil control rings on the pistons until it finds the 'happy' level again. But why foaming is bad is that air + oil does not build an incompressible wedge of oil in the bearings and prevent metal to metal contact and allow the oil to 'lay flat' on the metal and remove heat (and take it to the oil cooler). Foaming oil 'compresses' and is a poor lubricant (can't create a stable oil film wedge) and air mixed in (foam) doesn't remove heat very well. Oil must stay as a liquid, not foam, to work correctly.

Note to other readers: If you have high oil consumption for no apparent technical reason, as another pointed out, check the oil gauge. I have found one oil gauge tube to be the wrong part number (too long by 6 cm) and gauge (dipstick) was held up too high. Gauge was correct, but "guide tube" was wrong. And the oiler truck that comes each morning (construction site) just kept filling it up, showing another 6 liters a day consumption on the paperwork, and then oil was blown out in first hour of operation, the stack dried out due to 7 more hours of normal operation, so no evidence was there each morning. Calibrate the gauge by looking in book for EXACT refill capacity (with full or empty filter) and fill it EXACTLY with that amount and check your gauge marking. Especially trucks (lorries) with loooong gauges pulled from the little door in the front and hundreds of options for the type of lorry for the correct gauge and gauge guide tube !!!!!! Believe me, 10% are wrong.

Pedantics warning: Just keeping this simple, please.

PS: Is anyone out there impressed that a US guy can use 'Europe Speak' ?

Last head gasket used 3 gallons of coolant per week and took three months to start running down side of block.

If by over gauge you mean overfill, then as previously replied by others, it's not a good idea. If you mean over gauge with viscosity, this is not good either as the oil flow into bearings is critical especially during warm up. The oil needs to have a low enough viscosity to flow while cold, yet high enough to do the job while at operating temperature.

As far as oil below the radiator, I work with welders (stationary equipment). Many that are supplied with the Deutz engine use engine oil as a coolant. Especially when there is an air compressor being driven off the engine. As oil's many attributes are sealing, lubricating, cooling and cleaning it works well as a coolant also. So check your coolant hoses and see if they are high pressure for oil, or just plain rubber for anti-freeze.

Hope this helps.

"No matter where you go, there you are"

Overfilling can cause serious dammage to engine. I saw a Mercedes truck engine explode on first start after filling with oil. The oil was overfilled by a novice to an extent that it went above the pistons and on startng the pistons could not compress

the oil like they do the air and therefore the force developed ended up in splitting the head part and crankcase.

MIQ

Here's a great resource on wet stacking & how to avoid it. The site contains useful topics on a variety of generator and diesel engine related items.

http://www.cliffordpower.com/wet-stacking---why-its-important-to-load-bank-your-diesel-generator

Excerpt below:

Wet stacking and how to avoid it

Most standby generator systems up to five megawatts use the reciprocating internal combustion engine as the power source to

drive the generator that produces the electrical power. The engines of choice are either diesel, natural gas or LPG fueled. A large

percentage of standby power systems use the diesel engine. Diesel is a convenient independent fuel source and the compression

ignition systems of diesel engines have a much higher thermal efficiency than the spark ignition system used by gas engines. However,

one factor to be considered when selecting a diesel power source is the potential for "wet stacking."

The National Fire Protection Agency (NFPA), in their NFPA 110 Code for Emergency and Standby Power Systems section 6 - 4.2 (1996

edition) refer to wet stacking as a field term indicating the presence of unburned fuel or carbon in the exhaust system. The later 1999

edition suggests a more quantitative method for determining the presence of wet stacking by measuring the exhaust gas temperature,

explained later in this information sheet.

This information sheet discusses the causes of wet stacking, its effect on the engine, why it should be avoided and methods for eliminating the condition.

The designer of a generator system must take into account the potential for wet stacking when determining equipment for the system,

load calculations and maintenance and service programs. The system designer should consider the following.

Causes:

Like all internal combustion engines, to operate at maximum efficiency a diesel engine has to have exactly the right

air-to-fuel ratio and be able to sustain its designed operational temperature for a complete burn of fuel. When a

diesel engine is operated on light loads, it will not attain its correct operating temperature.

When the diesel engine runs below its designed operating temperature for extended periods, unburned fuel is

exhausted and noticed as wetness in the exhaust system, hence the phrase wet stacking.

Engine Effect:

When unburned fuel is exhausted out of the combustion chamber, it starts to build up in the exhaust side of the

engine, resulting in fouled injectors and a buildup of carbon on the exhaust valves, turbo charger and exhaust.

Excessive deposits can result in a loss of engine performance as gases bypass valve seatings, exhaust buildup

produces back pressure, and deposits on the turbo blades reduces turbo efficiency.

Permanent damage will not be incurred over short periods, but over longer periods, deposits will scar and erode key

engine surfaces. (Diagram One)

Also, when engines run below the designed operational temperature, the piston rings do not expand sufficiently to

adequately seal the space between the pistons and the cylinder walls. This results in unburned fuel and gases

escaping into the oil pan and diluting the lubricating properties of the oil, leading to premature engine wear.

Why Avoid:

In addition to the adverse engine effect, the designer and user of a system have to consider:

Expense Excessive wet stacking will shorten engine life by many years and before planned replacement.

Pollution Many urban areas restrict the level of smoke emissions wet stacking produces.

Power Even before an engine is damaged, deposits will reduce maximum power. A prematurely worn

engine will have a lower maximum power than it was designed to develop.

Maintenance An engine experiencing wet stacking will require considerable more maintenance

than an engine that is adequately loaded.

NFPA Guidelines

Wet stacking is a recognized condition with organizations that write codes for standby generator set systems, such as the National Fire

Protection Association (NFPA) which has issued several guide lines for controlling the effects.

The NFPA guidelines in Level 1 and 2 applications require exercising the unit at least monthly for 30 minutes under either of two

methods:

1) Under operating temperature conditions and not less than 30 percent of the EPS name plate kW rating, or

2) Loading to maintain the minimum exhaust gas temperature as recommended by the manufacturer. (See NFPA 8.4.2.)

Exhaust gas temperature specifications are available from the manufacturer of the unit.

Additional Conditions

The Joint Commission on Accreditation of Health Care Organizations (JCAHO), the organization that accredits health care institutions,

has taken this testing to a level beyond the NFPA. They require testing of 12 times per year with testing intervals between 20-40 days.

Testing generators for at least 30 minutes under a dynamic load of 30% or greater of the name plate rating. (Continued over)

The installation information provided in this information sheet is informational in nature only and should not be considered the advice of a properly licensed and qualified electrician or used in place of a detailed review of the

applicable National Electric Codes and local codes. Specific questions about how this information may affect any particular situation should be addressed to a licensed and qualified electrician.

Systems that do not meet the 30% load capacity have three options.

1) Increase the load to meet or exceed 30% of the name plate rating,

2) Maintain the minimum exhaust temperature as recommended by the engine manufacturer, or

3) Undertake load bank testing for a total of 2 hours continuous loading as follows:

a) Load at 25% of name plate for 30 minutes

b) 50% for 30 minutes

c) 75% for 60 minutes.

JCAHO also recommends that all automatic transfer switches (ATS) are tested 12 times per year at 20 and 40 day intervals. The provider of the power system through planned maintenance programs can undertake load testing when testing the ATS.

Solutions to wet stacking: