Service Tip #4: Standby Generator Annual Maintenance

Oct 12, 2009

Many land based Standby Generators do not get enough hours accumulated in a year to qualify for an oil change. Therefore, it is very important to do an Annual Maintenance on those generators. We usually use the advent of the Hurricane Season as our time to do this.

What does Annual Maintenance consist of?

First and foremost is to change the oil and filter, if this hasn't been done since last year. This is the life blood of your engine. Changing the oil (on time) alone on a Northern Lights generator can extend the life of your engine to 15,000-20,000 hours or more. Failure to do so can shorten engine life to less than 2,000 hours. Considering the investment you made in this piece of equipment, this is very cheap insurance.

While at it, change all of the filters: both primary and secondary fuel filters, air filter and coolant filter, if so equipped. Again, this is cheap and easy insurance. As discussed in previous tips, this is the time to change your engine coolant. You need to drain, flush with a good quality flush that is safe with aluminum components, then refill with a 33% or 50% pre-mix Ethylene Glycol coolant. Remember, if you have to add water, ONLY use Distilled Water. Check for water in your fuel tank. You do this by the use of water paste. Drain any water present of by pump or drain.

You might consider a tune up. On a Diesel Engine, a tune up consists of adjusting the valve clearance and testing the injectors. Most engine manufacturers recommend doing this every year. Not many engine owners actually comply with this recommendation however. This will eventually result in a rough running engine with smokey and smelly exhaust fumes. It can also result in a noisier engine. I recently did this to my own generator at home after 1600 hours and it made a world of difference.

Finally, test your Emergency Shut Down system. This consists of testing the Shut Down circuit at all of the switches (usually low oil pressure and high coolant temperature), and testing the switches themselves. The latter requires the switches to be removed and tested under pressure or high temperature. The time and expense to do this is often in excess of the cost of replacement switches. So, to save time, money and several trips, you might consider just having the person performing the work to bring replacement switches with him (or her) one time. For most standby generators, this is all the maintenance you will have to do for the next year, unless your generator runs for more than 250 hours, or you get bad fuel. Make sure you make the time, or the appointment, to get this work done.

Don't wait until you have a Hurricane bearing down on you before you do. Everyone will have their hands full then and you may find that your often-forgotten generator will let you down when you need it most.

Supplemental Coolant Additives

Oct 4, 2009

All coolants come with an Active Ingredient we generically call Supplemental Coolant Additives, or SCA.  The purpose of this ingredient is to make good quality water less corrosive to your cooling system.  It does not make poor quality water acceptable.  It also cuts down on what is known as “liner pitting” in wet linered engines.

 The products have been around for many years and greatly extend engine life in terms of cooling system corrosion.  But the active ingredient in these products dissipates over a period of time.  When that happens, they need to be replenished in your cooling system.  There are many SCA products available: Nalcool, DCA and Racor to name a few.  It is important to consult your Operator’s Manual or local dealer to find out which ones are acceptable in your engine.

The way to determine the level of SCA in your cooling system is to use a test strip designed for the purpose.  It will tell you the level of corrosion protection in your coolant.  When low, you add the appropriate amount of SCA.  This is very useful and, indeed, essential to getting the expected life from your engine. 

A simpler way of doing this is to just drain and refill the coolant in your system annually.  If you use a good quality coolant, the SCA is already in there.  Of course, if your engine holds a great deal of coolant, it is more cost effective to replenish the SCA.

If you fail to keep the levels of SCA up, the consequences are corrosion and liner pitting.  Liner pitting is the natural result of the combustion process in wet linered engines.  It manifests itself as 2 vertical rows of pitting 180 degrees opposite from each other on the outside of the liner.  It occurs when vapor bubbles collapse due to the expansion of the liner.  SCA coats the liner and reduces or eliminates the pitting.

Is there the possibility of “too much of a good thing”?  Unfortunately, yes.  The SCA have to stay dissolved in the coolant and held in suspension.  If you get too much in the coolant, certain parts of the mixture will “drop out”.  They crystallize and float around in your cooling system.  They can lodge in water pump seals, causing them to leak, among other things.

Coolant Quality: corrosion

Oct 4, 2009

One of the biggest service issues that have come to plague us in the last 15 years is coolant quality.  It used to be that when the radiator or header tank was low, we would just top it up with fresh water.  In the mid 1990s we started seeing a marked increase in internal corrosion problems.  This may be due to changes in metallurgy, but my suspicion is this is more the influence of the popularity of Reverse Osmosis Water Makers at around that time.

In any event, this has become a most serious and insidious problem.  We have seen it manifest itself in many ways.  We frequently see freeze plugs (commonly known as core plugs and water jackets) rusting out.  Those are designed to be sacrificial and tend to corrode out before the block.  The problem is once one starts leaking, all the others are close behind.  This may mean stripping down a great deal of the engine and removing the cylinder head in some cases.  We recently had a large 6 cylinder wet linered engine (an L6414) in our shop whose liners had literally rusted through and were leaking coolant into the oil pan.  In a dry linered engine, a rust hole in the liner means a new block or, effectively, scrapping the engine.

The shame of all of this is how terribly preventable this situation is.  If we just put acceptable quality coolant in our engines and flush the cooling system annually, it has the potential of saving $1000’s of dollars.  The customer with the L6414 paid nearly $25,000 to overhaul his engine.

What is acceptable quality coolant?  Any “name brand” pre-mix coolant is acceptable for most diesel engines.  Some manufacturers specify their own brand, and in such cases it is a good idea to use theirs.  Most manufacturers use a MIL spec, ASTM, or SAE specification which most quality coolant manufacturers adhere to.  Use a pre-mix, whether 50-50% or 33% (the latter being more than acceptable in the Caribbean).  If unable or unwilling to use a pre-mix, make sure that any water that is added is distilled water only.  The presence of any minerals will accelerate the corrosion practice.

When you flush your cooling system, be sure to use a good quality radiator flush.  We like Loctite 18E because it seems to clean all the rust and scale out of most cooling system with one application.  After following the instructions, keep flushing the cooling system with fresh water (this does not need to be distilled) until it comes out clear and free of debris.  Then fill it up with your pre-mix coolant and you’re good for another year.

In addition to providing corrosion protection, Ethylene Glycol coolants also protect against freezing (luckily not an issue in our Market) and boiling.  A 50% mixture of Ethylene Glycol Coolant (EGC) protects the cooling system from boiling to 226 degrees F (109 degree C).  A 40% mixture protects the cooling system up to 222 degrees F (106 degrees C).  The pressure inside your cooling system raises the boiling point even further, but it is nice insurance to have the ECG mixture in case of a pressure leak in your cooling system.

In the next Service Tip, we’ll discuss Supplemental Coolant Additives, what they are and how to use them.

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