Diesel Engine Problem

[D._Frederick]

I asked my neighbor why he wasn't using his JD 4040 and was told it had a blown head gasket. They took the head off, did not appear to be a gasket problem, had the head checked for cracks - $600+, no cracks. Started pulling barrels out, and found one with a pit that went completely through.

Question- how to prevent cavitation erosion, and electrolysis? I have a couple of tractors with wet-sleave engines and don't want the same problem.

[Rocky_J]

The oil must have been extremely acidic for an awful long time for that to happen. Perhaps he ran it for 10 years without changing the oil? Who knows? But it certainly does not sound like a common problem. I've never heard of 'cavitation erosion' before but it sounds like a fancy way of not telling the guy it was his own fault he tore up his motor.

Change the oil once in a while and the oil won't become acidic enough to dissolve steel.

[Fla._Deadheader]

  Could it have been a casting defect that ended up looking like electrolysis? Are the liners cast or turned steel

[D._Frederick]

Liners are cast iron, engine had been rebuilt 3 years ago, 1200- 1500 hours run time. The pit had formed from the cooling side into the combustion chamber.

Anybody know anything about using zinc anodes to stop electrolysis?

[Fla._Deadheader]

  On Marine engines, screw-in zinc anodes are installed into the manifolds and oil and water coolers. Don't know if they would work on non-marine without creating a film of corrosion from the anti-freeze, that would seal them off and prevent them from doing their job???

[Corley5]

Diesel manufacturers are recommending an anti-cavitation coolant.  The plain old green anti-freeze isn't recommended anymore.  I've heard of cavitation holes in the sleeves of the Navistar engines in Ford trucks.

[Deerlope]

I have a Ford diesel pickup and know about cavatition. there is an additive that is added to the coolant to help prevent this. I buy it at my ford dealer and its called FW-16. However there are test strips out there to check the coolant to make sure you put in the proper amount. can be had thru NAPA. some coolant such as CAT all ready has the additive in it.

[Mark M]

D

You need to add the Supplemental Coolant Additive (SCA) at regular levels and test its level periodically. Also you need to use a diesel engine antifreeze coolant with the necessary additives. Zinc anodes are not commonly used in diesel engines (non-marine) but I can't remember the exact reason. Another thing that is important is to make sure the electrical grounds are clean and in good condition. Since the coolant can and will conduct electricity you can have serious problems in a very short period of time if you have some stray currents. The appearance of the pits in the liner can sometime give clues as to what is causing the holes. Electricity usually results in smooth surfaces where as cavitation erosion/corrosion appears differently. Another problem is not having enough glycol as it provides boil protection. Bubbles form on the surface of the liners and when they rupture water that is much cooler contacts the liners causing damage to the surface.

If you tell me which coolant you are using and it's color I can recommend the correct additive. Or better yet send me some and I run it through the lab and give you some detailed information.

In the mean time you can go to http://www.butler-machinery.com/oil.html and click on the Coolant and Coolant Analysis presentation link for more info.

Mark

[rebocardo]

> 'cavitation erosion'

What happens is the coolant turns into steam bubbles from being frothed up and the microscopic bubbles adhere to the cyl. wall lining causing very tiny hot spots that burn off the liner or destroy the cyl wall from the piston side. Or sometimes it will wipe out the whole cyl when only one side is cooled or wipe out a whole block.

The reason anodes are used are to attract the bubbles to them instead of the negative charged block.

Usually you have to use the pink coolant or Dexcool (orange) with additive depending on your application. A coolant filter is usually used on the bigger rigs too.

[D._Frederick]

Is the anodes an aftermarket product and where are they installed in the engine cooling system?

[Mark M]

In cooling systems there are several processes that cause corrosion and pitting. Galvanic corrosion takes place when different metals are present in a conductive liquid such as antifreeze or seawater and an external path of current flow is possible such as an iron block, aluminum manifolds, copper fittings, etc. If you hook a voltmeter between the metals you can measure a voltage difference and one metal will have a higher potential. Arranging these metals from lowest to highest voltage gives a galvanic series. A natural current flow will take place with current flowing externally from the higher voltage metal to the lower voltage metal. To complete the path the current then flows through the coolant or seawater and in the process corrosion occurs at the metal of lower voltage (the anode). If you look at the galvanic series you can see that zinc is the lowest voltage metal (remember to consider the negative values so that -0.98 is lower than -0.30). This is why you see zinc anodes on the lower unit of outboard motors. The zinc will corrode instead of the aluminum housing.

Another cause of corrosion is electrolytic corrosion or electrolysis. The best example of this is electroplating. Here a current is applied to a metal such as silver which is placed in a conductive solution along with a part to be plated such as an iron nut. In this case the voltage cause silver to be transferred to the iron nut, against the natural flow. This is what happens when there is a bad electrical ground in an engine. The results can be devastating in just a few hours. Anodes or additives will not help this problem, only good electrical grounds can help with the problem so make darned sure you put that ground wire back on the radiator or engine.

The third and most common cause of pitting is cavitation erosion/corrosion. This is a combination of mechanical and chemical or electrochemical action that causes corrosion. There is some disagreement as to the exact process but we know that it involves vibrations in the cylinder liners and the formation and collapse of bubbles. What we need to know about this is it can be prevented with the proper coolant and additives. This is the reason we test for and add the supplemental coolant additives. You absolutely MUST use the corrosion inhibitor additives in diesel engines that have closed cooling systems. If not you will have pitting problems that can eat right through the liner. In the worst cases I have seen a hydraulic lock occur when coolant drained into the cylinder. When the operator tried to start the engine the connecting rod broke and punched a hole in the block!

Back to the anodes, they might help if current flow is present as in galvanic corrosion but it will not do anything for the cavitation erosion/corrosion, nor will it help if you have a bad electrical grounds. The zinc anodes are used in raw-water cooled marine systems where antifreeze and additives cannot be used. Here the main source of corrosion is galvanic corrosion. I am not aware of the anodes being used in non-marine applications by any of the major engine manufacturers. There is an aftermarket company marketing a zinc anode for racing engines but I cannot comment on it’s effectiveness as I have no experience with this product.

As for coolant type, Dex-cool is Texaco’s automotive (gasoline engine) extended life antifreeze and is standard in GM products. This orange colored coolant does not have the necessary additive for diesel engines and should not be used for this purpose. They make several other extended life coolants for diesel engines which are red or red/orange in color. The primary difference is nitrite is added to protect the liners. Caterpillar and Texaco co-developed this coolant and it is sold under several names including Havoline, Cat Extended Life Coolant (ELC) and Shell Rotella ELC. Cat is recommending 12,000 hour change recommendation for off-highway equipment (600,000 for trucks) using the ELC which is a lot longer than the standard 2000 hour 200,000 mile recommendation for conventional coolants.

The most important thing with diesels is to use a good quality diesel coolant with the necessary additives to protect the liners. Use a 50:50 mix of coolant and distilled water. Don't add too much antifreeze or you will have trouble overheating. Test the additive level periodically and make sure it has the recommended level of nitrite or nitrite/molybdate. Add only 50:50 mix unless a freeze point adjustment is necessary. Add the SCA only when it gets below the minimum level to avoid water pump seal problems caused by additive dropout. Use good quality fully formulated diesel engine coolant and additives such as Cat, John Deere, Fleet Guard, Texaco, Penray, etc. Avoid low price automotive coolants.

Let me know if you have any specific questions, this is how I make my living.

Mark

[Rocky_J]

WOW! I've learned a lot out of this thread! Thanks guys, especially Mark. I will mentally file this information away for future reference when dealing with diesel engines. Maybe next time I won't sound like an idiot.

[Mark M]

Don't feel bad Rocky, there is a lot going on in cooling systems. I consider them to be the most complicated system in the equipment we work with. You would think it would be nice and simple: put antifreeze in, coolant circulates, cools engine; but there is so much chemistry going on with different reactions and physical processes occurring simultaneously that even the experts have a hard time understanding or agreeing what's happening. The new engines are pushed to the max to get the HP and this put a tremendous load on the cooling system. In fact about 30% of the available energy is put through the cooling system whereas 33% does the work. If you have older equipment you can get away with a lot more in terms of maintenance or lack thereof. You still need that inhibitor though.

                   

[D._Frederick]

Hey, thanks Mark for all the information, will get some antifreeze from JD.

[ksu_chainsaw]

So, after having read this thread, I now have a few questions.  

What is the best kind of antifreeze for all sizes of diesel engines.  I run and maintain diesels from a Cummins in my pickup up to the 8400 JD that we do field work with.  Currently we take the JD equipment into the dealer to have the service done, as we have a good deal with the dealer (he is a longtime family friend ).  In our older diesels, such as our 706 Farmall and the pickups, we use the Champion brand antifreeze that we get at the local farm store.  Is that stuff ok for them, or do we need to get something else?  I like using JD stuff, but I know that it gets expensive realy quick.  Is there something else out that is readily available and a little cheaper (dad doesnt like to spend that much at the dealers when he can get by with something that is cheaper, and does the same job)

Thanks for all your help, this thread has given me a lot more knowledge than I had before.

Charles

[Mark M]

Hi Charles

Well the JD antifreeze is certainly a good choice. I am not positive but I am pretty sure it is made by FleetGuard, a Cummins company. You might compare prices for the JD and Fleetguard and see if there is a difference. As for the farm-store stuff there is a good chance that it does not have the necessary additives. Many times they sell the coolant without the necessary additives so a precharge is necessary. Look for the container to say RP329 which is a common spec for fully formulated diesel engine coolants. Typically diesel engine coolant are low silicate so this is something else to look for. Silicate additives typically last about 250 hours if I remember correctly and have to replenished. The problem is since the coolant in diesel engines may be used up to 200,000 miles there will be a too much silicate added and it will precipitate out. Since its solubility is affected by pH and since oxygen entering the system lowers the pH the silicate can precipitate in the water pump seal area. The seals are usually made of carbon and don't last too long when the silicate "grinding compound" starts to form.

If you have newer equipment I recommend the use of the Extended Life Coolants such as the Cat, Texaco, or Shell brand. Fleetguard, Detroit Diesel and most companies have similar products and they all work well. I do not recommend using these coolants in older systems as they are very effective cleaners and will remove old deposits that are frequently plugging holes.

Gasoline engines do not need the liner protection additives (nitrite, molybdate) but in most cases it shouldn't cause problems. Here your farm-store coolant should work well. As for the 706 you could use the lower price stuff and just add some of the supplemental additive. If you tell me the system capacity and the brand of additive you decide to use I can tell you how much you need to add.

Good luck and keep you head down!

Mark

[MrMoo]

Ya I have seen this problem with corrosive coolant before too. Last year my JD loader backhoe started to lose coolant but wasn't leaking out. Didn't take long to find it in the crankcase. One of the cylinder liners was perforated. I had the engine rebuilt. It turned out that a second liner was also ready to go. My brother in law took the machine down to his shop & did the rebuild. He said it probably had been going for longer than I owned the machine. I was pretty mad at myself for not knowing about this issue. He was nice though and assured me it started years before I owned the machine.
I now have have an engine that runs great. Had it not been for my brother in law this would have cost me thousands of dollars as we rebuilt the entire bottom of the engine & had the head done to. In the end I spent about a grand on parts, $200 on the head and $200 on labor. My brother in law also gets to use the backhoe when he needs it.
I also now know to check the coolant in the engine periodically.

[D._Frederick]

Mark,

I will take you up on your offer to tell me what kind of anti-freeze my tractor needs. It is:

Case IH   model 685, The cooling system holds 14.5 guarts. I use the tractor just a few hundred hrs a year. The temperature here reaches about 0 degrees F.

                                      Thanks for the help.
                                       D. Frederick

[Mark M]

D. do you  have any partcular equipment, engine dealers, or fuel dealers you like to deal with? Unfortunatly I am not too up to date on Case IH supplies so we will have to try another brand.

One more question - do you have a coolant filter on your engine?

Mark

[D._Frederick]

Mark,

NO coolant filter on the case IH 685, JD dealer will do find, they all know how to charge!

                                D. Frederick

[Mark M]

Hi D.

John Deere has a product called Cool-Guard with a service life of 5000 hours. It is available in 50:50 premixed or concentrate. I usually recommend the premixed because you can be assured of having good quality water and avoid possible warranty issues that can arise from using water of questionable quality. Also its more convenient for top-off. The part number for a 2.5 gallon container of pre-diluted is TY16036. When you change check to see if you can see deposits in the radiator and if you do then use a fast-acting flush. After you have drained the flush then change water at least 3 times and better yet 4, allowing it to reach operating temp each time and with the heater valve (if so equipped) wide open. Then you can add your new coolant and you should be in good shape. The Deere dealer should be able to give advise about adding the inhibitor.

Good luck
Mark