switching to synthetic oils

Did it use oil using 15w40 mineral? Mine uses oil and its got 113k on it and I'm using 15w40 mineral (castrol gtx) I could use magnatec but i won't.

If you use synthetic at motor of this mileage you will ruin it instantly. Synthetic resolves all kind of bound dirt which will you like sandpaper through your engine. Although its pointless tu use thinner oil because every type of engine needs just the oil-thickness for which its built.

Raoul

NO.

If you switch to a synthetic oil you'll be asking for trouble. Not only is the engine not designed for it, but it will do an excellent job of flushing out the engine, and it will rattle, clunk and clank from then on. The dirt and sludge will be fed round the engine, causing premature wear and tear on almost everything, finally accumulating in the filter which will clog up. Low oil pressure bekons due to unclogged oilways and clogged filters. Valve lifters will probably get clogged as well, resulting in noisy tappets...The list goes on.

The engine has been run in and beyoned on Mineral, then you should keep on using mineral. You might consider a mineral oil with Diesel Additives, and 15w40 is probably better for a diesel than 20w50, although there's not a great deal of difference in the grade.

You could switch to semi-synthetic, but it's not reccomended for the same reasons, and the engine neither needs it or is designed for it. I would never consider switching on an old engine, unless the engine has been completely stripped, cleaned, re-worked and rebuilt. And even then, there's no advantage as the engine does not need it. A good quality Classic 20w50 with detergent is the best in this case.

Alex

Raoul Donschachner wrote: >Although its pointless tu use thinner oil

Most of an engine, except at the brief periods when it starts operate so far above normal air temperature that they barely vary with weather conditions. Peak oil film temperatures in the big-end bearings are >>

150 deg C, and similarly in the piston rings and tappets, film temperatures are very high.

The 20W- part of the J300 specification refers to the maximum viscosity of the oil at -15 deg C, and guarantees that the engine will crank fast enough to fire. A 0W will crank at -35C, at 5W at -30C, a 10W at -25C etc.

The second figure of the oil (50, 40, 30...)is derived from a Kinematic viscosity measured at 100C and a dynamic viscosity measured at 150C and the J300 spec sets a *minimum* viscosity that must be exceeded to ensure sufficient lubricant film thickness to protect the moving parts of engine. AFAIK a lower viscosity improves fuel economy and the higher viscosity improves engine life. The trick is to get the right trade off between cranking, fuel economy and engine protection and that is where the additive package comes in to play.

The chemical additive packages in fully formulated multigrade lubricants are what allow good oils to be thin enough to crank and thick enough to lubricate and not to degrade too quickly and as with everything life you get what you pay for.

Steve & Lizzy

Why do people always assume that syntheitic oil is thin?? Why not reap the benefits of a synthetic oil and still use one that is the specified grade?? Use a 15w40 or a whatever grade of synthetic oil - and don't do the usual cheapskate trick of leaving it in the engine longer 'cause you can. Change it at the same intercal as you would a mineral oil but be better pritceted whilst it is in there!

David LLAMA 4x4

As far as my knowledge and experience goes, you don´t do any good to older engines with thin oil. My Mini for instance runs abnormal hot and looses oil-pressure in hotter days if run on 15W-40 instead of 20W-50 what is recommended. And the Mini has just covererd 25k so the engine is not worn at all. I wouldn´t mess with thinner oils hoping for better fuel economy which would be in the 1-2%area if any.

Raoul

I don´t do it, the original poster asked about him using thinner oil, regardless of mineral and synthetic. As I stated before, if you use synthetic on an engine with that mileage, you just ruin it because of the resolved dirt. Thats a fact because it is one of the merits of synthetic oil.

Raoul

A friend who owns and runs a garage says' that he's seen more damaged engines over the years caused by oil problems than anything else. His advice was simply to put in oil of the manufactures recommended type for your engine and change it frequently, even sooner than the recommended intervals.

bw Gail

Thats what usually the experiences are.

Raoul

All oils of suitable grade and changed within its limit reduces engine wear to virtually nothing, otherwise your engine would not have lasted 50,000 miles let alone 230k.

It would be a good idea if you changed to an appropriate grade for your engine. That is not it. You need an oil with a current specification not API CC which has been obsolete for two decades. Might I suggest API CH4 which provides everything your engine needs in terms of contaminant handling and long service life. Believe me your engine is one of the worse ever for chucking shit into the oil. Even using CH4 oil, the absolute maximum between changes should not exceed 5000 miles. This should not be exceeded even by a synthetic diesel specific oil due to the soot load in the oil. It therefore follows that a synthetic oil is a waste of money in this engine as none provide any advantage over a good mineral oil. Also 15w/40 is the appropriate viscosity for your engine at this mileage, or any other mileage come to that.

No

Are you saying that it doesn't leak already?

I won't answer the first part of this question but your 20w/50 appears to be inappropriate from the specification you have provided. If you use this, expect severe engine sludge at an early date.

Only in cold weather cold starts. If you leave it in the engine too long this situation will result in a seized engine. A poor oil from the detergent point of view will thicken due to the soot load very quickely. I have found that a standard oil of API CD or CE thickens frighteningly in mine by 4000 miles yet a CH4 oil shows no sign of thickening at 5000 miles, both being of short journies with many cold starts and some bursts of heavy towing.

Huw

This is compulsory. This engine will not function long without diesel high detergent oil. Any oil which has a current diesel rating will be high detergent and higher than many synthetic oils without a diesel rating so this nonsense about loosening crap is just that, crap, in this application.

and 15w40 is probably better for a diesel than 20w50,

Whether an oil is synthetic or not is totally irrelevant when talking of this engine. A synthetic oil will not provide a single advantage point over a diesel specific oil or a multifleet oil with dual rating such as commonly available API SL/CH4. I do not know of any oil that will magically perform better than this in an engine which is just so dirty.

Huw

On or around Mon, 8 Nov 2004 10:15:14 -0000, "Huw" enlightened us thusly:

this was my problem with finding 20W50 for the earlier V8s, it's very hard to get decent quality, and SG or better (which IIRC is the point where anti-sludge properties become notable) is like rocking-horse fuvg, unless you buy very expensive stuff like silkolene semi-synth.

will a synthetic oil (say 15w40) clean gunk from inside the engine as Raoul says? and if it does and I do a first oil-change at say 3k will I then have a cleaner better engine?

Although I'm now tempted to stick with the 10w50 mineral oil.

Regards. Mark.(AKA, Mr.Nice.)

I was told that synthetic oil suffers from capillary creep, but mineral oil doesn't. That means that even if it's the same thickness, you're more likely to find the synthetic making its own way out of your engine than you are with mineral oil.

But I don't know if this is true.

David

I know the difference is small but I went for the thicker oil due to the mileage of the engine. and it now uses no oil (5000 miles). both the haynes and the LR manuals say 14w40 or 10w50 are both ok.

would I really be better with the 15w40? why?

Regards. Mark.(AKA, Mr.Nice.)

Not, this won´t work. If you do a complete overhaul, then you can use it, in the already clean engine, but without sense except more expenses for oil.

Raoul

Fair enough.

I'm sure the manual says 20w50 is fine, that's why I chose it.

It has damp oily bits like expected but 5000 miles and the dipstick level had dropped maybe 5mm. in land rover terms I call that not using oil...

I shall make an oil change a priority then. Is and why 20w50 a bad idea? When I'm shopping for oil, what am I looking for on the markings? Am I likely to find good oil in unbranded or shop-branded oils or should I stick to castrols or whatever?

This next oil change will include (probably though I may change it before) a trip so scotland in the winter, I'm expecting overnight temps of -10c and daytime no-lower than 0c, this is cold by cornwall standards..

Regards. Mark.(AKA, Mr.Nice.)

I didn't say that, Alex did.

20w/50 should not really be used below 0C ambient. Apart from that there is nothing wrong with it in your application as long as it meets reasonable current diesel specific performance standards.

Huw

The viscosity is the least of your worries. AFAIAC 20w/50 would be fine in moderate conditions as long as appropriate performance standards [as distinct from viscosity] are met.

But does it leak? Your consumption is indeed good for this engine at any age but consumption is not generally caused by leaks unless the leaks are extreme indeed. FWIW mine doesn't leak either but it has only done 120,000 miles of farm work with very few, if any, journies of more than 20 miles in the past 15 years. It does, and always has, used around a litre of oil every couple of thousand miles though. It is also prone to the oil pressure light flashing if involved in heavy towing for an afternoon but only when idleing. It tows a 16ft cattle trailer regularly.

You appear to confuse the importance of the viscosity with the performance grade of the oil. Again I have to say that there is nothing wrong with the viscosity at this time of year but you quoted a performance spec which is not sufficient for this engine and was not sufficient even when API CC was current in the 1960's. In fact at that time LR diesels had a maximum drain interval of 4500 miles if memory serves me.

Brand is unimportant. What you should look for is an oil with API CF4 or CG4 or much better CH4 on the can. These standards were not available when your vehicle was built.

A 20w/50 should not be used for cold starts at -10C. 15w/40 should be the most viscous oil you should consider even for an engine with your use under its belt.

Huw