Feed back request on Exxon Ellite Oil any problems

[horizon flyer]

I am looking for any problems that have occured when running on Exxon Ellite Oil.

Our experience.

Engine Lycoming IO360 A1B6

100 hours after a rebuild, for a prop strike we changed to this oil.

At 240 hours (140 hours on the Exxon) we suffered an oil leak from the centre bearing, oil dribble from a through bolt.

This required engine removal and splitting the cranckcase to find the cause.

On investigation the oil was found to be very thin and loaded with carbon, plus all main and big end bearing worn to the backing with 2 breaking up.

The camshaft, which was brand new was found to have been damaged, and the bearing surfaces in the cranckcase.

All piston rings worn, exhaust valve guide worn and the valve keepers had worn into the valve stems.

Ancillery gears worn with one chiped tooth, oil pump housing scored. Crankshaft marked

At no time did we see low oil pressure or high temperature.


Horizion Flyer

[Lister Noble]

I'm not an expert on aviation oils but do know a little about competition car engines.
If you have been running on a low detergent oil and change to a higher grade detergent oil ,then all the carbon build up around bearings,seals etc will be "washed" out leaving large clearance just where you don't want them.
Is this a possible scenario with your new oil and engine?
Lister

[2Donkeys]

I would have expected you to run on straight oil for 25-50 hours after a rebuild.

If, as your note implies, you didn't do that, then I would expect any number of issues with the engine.

2D

[Fuji Abound]

2D

"100 hours after a rebuild, for a prop strike we changed to this oil"

I think they did - I thought 50 hours on straight was relatively normal.

Lister - I dont follow your reasoning. If the engine was run on straight for the first 100 hours and then Elite thereafter no low detergent oil has been used to produce the wash out to which you refer. I could understand this if a change had been made a few hundred hours into an engines cycle or if the carbon deposits had not been removed when the engine was overhauled (possible?).

Interesting topic as we had some potentially similiar problems although not as severe. Oil anaylsis every 50 hours had not revealed any advanced warning. Did you have regular oil analysis?

I shall be interested in other comments.

[Lister Noble]

Fuji,
I don't know anything about aero engine rebuild spec or aero oil specs,do they clear out all the oilways etc during a rebuild and whether Elite is high detergent?
I was just specultating on possible causes from a competition car / race engine point of view.
We tend to use 100% synthetic oils in race engines as they definitely give better high temp protection and keep the engine very clean,although I don't think synthetics are used so much for 4 stroke aero engines but stand to be corrected.
Lister

[EddieHeli]

I use it in my AA1 and have had no problems. The engine seemed to drink quite a bit of it just after the annual, but has settled down again now.


Here's the blurb from the Exxon elite web site as to why its only semi synthetic.

Exxon Elite is a blend of synthetic and mineral-based oils (plus a highly effective additive package). Why a semi-synthetic? Our engineers determined that a fully synthetic oil may not have the solvency to handle the lead deposits that result from the use of leaded fuel. So they developed Exxon Elite as a semi-synthetic formulation that combines the best of both synthetics and conventional oils.

As a multigrade oil, it offers the flexibility to lubricate effectively over a wider range of temperatures than monograde oils. Compared to a monograde oil, a multigrade oil provides better cold-start protection and a stronger lubricant film at typical operating temperatures. Other benefits include lower oil consumption and better fuel economy. As a premium multigrade oil, Exxon Elite has all of these intrinsic advantages.

[horizon flyer]

Oil was changed at 5hrs 25hrs with straight oil then at 50hrs with
W80 then at 100hrs with Exxon then every 50hrs.

Then in the last 10 hrs, due to the small oil leak 1 ltr was being added every 2 hours.

Found after 140hrs on Exxon. Thinning not noticed as this oil is expected to be a little thinner, at lower temeratures and be a little blacker in operation. Due to the high detergent action.

Exxon Mobile had to withdraw full synthetic oil, AV1 fast due to engine damage. Did not carry the lead salts very well, due to the high piston blow by in aviation engines. Shell did warn them about this, but they ignored it. Thats why Shell never produced a full synthetic aviation oil.

Car engines have closer tolerances, better oil scrapper rings and run on unleaded fuel, so far lower lead salt load and Mobile 1 works very well. Not so good in older classic cars, its to thin.

Of course Exxon would say their oil is wonderfull, but they did ship a lot with very fine iron particles in it, from a pump impeller breaking up in the refinery, not great quality control.

So if you have a grey sludge left in the bottom of you oil containers, thats what it is. Supposed to be fixed now.

I believe they have only lab tested this oil with a minimum of field testing, not good. Even their supposed cam wear test is not a realworld situation, as most wear happens at startup not running.

I would monitor an engine very closely running on this oil, as several engine overhaulers are reporting higher wear and lower time to TBO, on engine cores being returned, that have run on semi-synthetics, but strangley no one mentions any oil companies. They don't want to be sued


Horizon Flyer

[Lister Noble]

Horizon,
I reckon the high detergent action could possibly be the problem by releasing any carbon/crud build up around internal oilways in the rods,crank,camgear and galleries.
Very difficult to prove though.
Out of interest, I have run a 1936 vintage Riley 9 sports/racer on 10-40 semi-synthetic and two classic 1960's race cars on 10-50 fully synthetic without any problems for several years.
Anyway,I wish you good luck with sorting out your problem as it all sounds a bit horrendous!
Lister:D

[S-Works]

I had a similar problem, engine had 2000hrs on, 200 after a top overhaul. Oil test were fine, switched to exon and the engine failed 150hrs later requiring replacement.

I am not the only one to experiance this, heard of a zero timed engine at Derby that failed at 200hrs and balmed on Exxon.

I use shell multigrade now.

[A and C]

A lot of stuff being said about the Exxon muiti-grade but I have yet to see any real hard evidence of problems with this oil IF it is used in an engine that has fresh from overhaul (after the inital break in with S80/100).

The problems seem to start if you switch to a multi-grade after more than about 400 hours, the fact that these oils clean the carbon out of the system and some of it is deposited in the oilways seems to be at the core of the problem.

There seems to be very little said about the Shell multi-grade the product has been on the market for the best part of 15 years now and any problems with this oil should have become apparent by now.

I have now started running Shell multi-grade in three of my engines that have been recently overhauled and only time will tell if this is the right thing to do but the engine that I have direct operating control over has burnt less that 1 Ltr of oil in the last 26 flying hours and I suspect the other Two engines have burnt about the same (but I don't have the numbers to prove it !).

Corrosion is a big problem with low use engines and the Shell oil seems to combat this , Cessna 152 engine rocker boxes are a very good illistration of this as the rocker boxes sit in the "cold" air above the baffels and are subject to a lot of condensation at the moment it would seem that the Shell oil is controlling the corrosion in the rocker boxes much better than the "W" oils but the next 150hour/Annual check will be the real test of this as the problem is much more apparent in the winter.

The next big marker will be at around 11-1200 hours when I would expect the Cessna engines to need a top end overhaul if the engines run to say 1500 hours then the almost 100% increase in the oil costs will have been a good investment.

[S-Works]

the question was about Exxon not about multigrade. The shell multigrade has been suberb, the Exxon has been very debatable and I am not the only one to suffer.

To add to my earlier post, my engine had done nearly 2000hrs on shell multigrade before switching to Exxon.

I personally think it has problems.

[horizon flyer]

From what I have learnt, I agree with A and C

Exxon Elite oil does have some problems that can happen in approximatly the first 300 hours of use. This is a low chance your engine will show metal in the filter and need work.

There will also be a high proberbility it will leak oil all over the place. Ours went at 140 hours and could have ended in an in flight engine failure, if our engineer had not caught it in time.

Why should this happen,

I believe the problem with this oil is due to its very high cleaning action. It is being reported that on the first two or three oil changes it, comes out very very dirty.

This is all the carbon being cleaned out of all the nooks and crevises.

This carbon can then go on to block small oil passageways, leading to bearing failures. Another contributry factor is the very
low viscosity, this points to a lower film strenth, so can be sqeezed out of bearings at lower loads, unless there is a very good flow into the bearing, so sensitivty to low flow rates.

Again the Shell 15/50 does not have any history of this problem
and does seem to stay inside the engine, compared to Exxon ,which finds every place it can, to get out.

From what I have learnt, I believe Exxon is not worth the extra money and risk, the Shell products have a better track record and I would advise anyone considering using it, to think carefully and don't believe all the claims for it. Remember its your money and life.


As an aside a similar problem happens on turbo charged cars that
run on mineral then are changed over to synthetic, the released carbon blocks the small oil way into the turbo bearing and a new one is needed.

So if you change over on a turbo charged aircraft could be even more expensive.

[Fuji Abound]

Horizon Flyer

I have a problem with the conclusions you reach.

Quite simply you appear to offer no evidence at all - not even anecdotal, as there have been so few comments on this thread. How can you possibly conclude as you do?

Equally, I am NOT saying your conclusions are wrong. In fact I am very interested in the topic having used this oil and now wondering whether to use it again.

Come on, lets have some hard facts, if they exist or at least rather more evidence by experience.

[IO540]

I used 80/100 from new, then Exxon Elite. Engine IO-540-C4.

No problems at all in 400+hrs over 3yrs, no metal (have oil analysed by a lab in the USA at every 50hr check) and the oil consumption is about half a quart every airborne 50hrs.

I fly at 60-65% power, LOP all of the time except in full power climb.

2D - I think that straight oil in the first 50hrs (or until oil consumption stabilises, if this occurs later) is purely for cylinder anti-glazing reasons. If new cylinders are not fitted then does one still have to use mineral oil?

[A and C]

You are correct about the use of "straight" oil but if you take an engine apart the chances are that you will change the piston rings and hone the cylinders as the added expece in negligable.