Originally Posted by smurphny
After reading the link posted by Capitain Mike, it is clear that newer lube oils and especially synthetics are not suitable for older designs such as my Yanmar
3GM30F. There are lots of these still in service so this could be critical info for many boat owners. My service manual does call for API service CD, an obsolete product. According to this article, it could well be that the oil
burning problem I had was caused by using newer Rotella and not by the previous owners running at a low rpm
. Rotella IS recommended in the manual but since there is no copyright
date in the manual, there is no way to tell whether the Rotella then is the same as the Rotella now. I would think not. I have used Rotella in every diesel
with good results but it is possible it is the culprit, as described in the link piece. Being that I have no desire to repeat the ring job, will be looking further into this.
Get a ceramic magnetic oil pan plug
In warm weather
, a good-quality non-synthetic oil meant for diesel engines with CG-4 or CH-4 ratings may be used. They're not suitable in cold weather
due to reduced cold-pumping properties, and it's prudent to shorten the oil change
interval because non-synthetic oils may not resist breakdown at high temperatures as well as the synthetic oils (remember that turbocharger). These oils are much easier to find. These include:
Mobil Delvac 1300, 15w40
Shell Rotella T, 15w40
Chevron Delo 400, 15w40
Beware of other brands that claim to be diesel-rated or turbo-rated, but are actually just plain cheap
. Use the good stuff. If you doubt this, ask transport truck drivers that own their rigs what they use. Chances are it will be Delvac or Rotella.
In cold weather, if CG-4 or CH-4 rated synthetic oil cannot be found, regular Mobil 1 rated CF in viscosity grades 0w30, 5w30, or 10w30 may be used, but with a shortened oil change
interval because this oil doesn't have as much capability to handle soot.
So what's the deal if something else is used besides the expensive and sometimes hard-to-find 5w40 full-synthetic CH-4 rated oil?
Conventional oils that are meant for diesels are usually viscosity SAE 15w40. That's okay in warm weather, but not in cold weather. You want oil to reach that turbocharger as soon as possible after a cold start, and it takes longer to get there if the oil won't pump easily. Synthetic oils have many advantages over conventional oils, not the least of which is better cold pumping characteristics, and hence the common 5w40 viscosity grades.
It is possible to get some non-synthetic oils with viscosity's such as 0w30, 5w50, etc. In non-synthetic oils, these can only be achieved by heavy use of viscosity-index modifiers, a type of additive, whereas synthetic oils can easily achieve a viscosity range like 5w40 with little or no use of viscosity-index modifiers. For various reasons we'd rather not get into, it's better to have the viscosity right in the base stock, than to tinker with the viscosity using additives.
Oils that lack the CG-4 or CH-4 rating don't have the same level of anti-foaming and soot-dispersing capability. The best quality diesel-engine oils deal with it and render the soot as harmless to the engine as possible. Oils that don't meet the CG-4 or CH-4 ratings can't handle as much soot, so you need to change them sooner.
Finally, cheaply made oils (not the same as cheaply priced ...) usually won't have the same resistance to breakdown at high temperatures, that good quality oil does. High temperatures are found in the turbocharger. When oil breaks down at high temperature over a period of time, it "cokes" or builds up deposits in the high-temperature area, which then restrict lubrication. Bye-bye, turbo. There has been one reported turbo failure which was traced to lubrication failure. Do a search of the forums
for "turbo failure" to find out what oil he was using...
Many oil additives contain PTFE, also known as Teflon, and touted under many other different names after the manufacturer of Teflon filed a lawsuit to prevent oil-additive companies from using that name. PTFE is a solid. The job of the oil filter
in your engine is to collect solid particles down to about 10 microns in size. Where's that solid PTFE going to end up? In the oil filter
. Which may cause the filter to plug
prematurely, causing the bypass valve to open, and now your engine is running on unfiltered oil. Not good.