Just want to get some opinions here. I haven't gotten an oil change on my 94 FD in a year. I put in redline synthetic last time. But, I've only driven 500 miles over the last year. Do you think the oil has broken down since my last change..not because of mileage, but because of the time.

 

General wisdom is you change your oil every 3 months or 3000 miles, whichever comes first. So, in theory, the oil does break down when it sits in the engine. But, it's hard to say if that's marketing or real science.

Since you have Redline in there, it might be worth contacting the folks at Redline and ask their opinion. They're very friendly and helpful.

Dale

 

For me, my FD is my weekend driver. I drive it 1 or 2 times a week and that's just running errands only. But even then, I still change my oil/filter on regular basis every 3month/3000 miles as Dale noted above. I have accumulated about 6,500 miles total since Spring '05. I guess I just like to make my FD checked out on regular basis and for safety's sake. So I would recommend changing it anyways...nothing to lose other than cost on oil change supplies and an hour or so.

 

This is the norm for dino oil. Different factors come ito play as well for the 3mth. 3k mile.....kept in a garage (less dramatic temperature swing) or outside. Mine is outside and the temperature change is severe enough to have condensation form on the motor parts (same thing probably happens internally as well.

 

The oil doesn't really really break down on it's own. I mean it does, but not over a few months or a year on it's own. There are guys on Bob The Oil Guy's site who stash oil for years. The oil you buy in stores sits in warehouses and store shelves for months before you get it.

Given that, I would recommend a change at least in a year and a half of your last oil change, just to make sure you didn't accumulate any moisture in the oil.

 

I believe that the three month rule has to do with acuumulation of moisture in the engine. Daily temperature changes cause moisture from the air to condense on the metals as they cool, which will eventually lead to an accumulation of water. Driving the car more regularly will cause the water to evaporate and will prevent condensation because of heat.

As far as the oil breaking down, I think the only things that cause that are contamination, heat, and pressure.

If you drive your car that infrequently, why not put it into storage?

 

Instead of going crazy, why dont you just change it again?

At least you'll have a peace of mind knowing its all said and done and even though you spent money even though you "think" you shouldnt have, now you know its done because eventually it will have to get done again.

 

Hmmm the whole synthetic oil thing i dont think is good since oil it squirted into the combustion chamber the synthetic oil dosnt burn clean and creates sand deposits and other such things as regular oil dosnt do that. Castrol GTX is what is recommended.

But im not sure on the redline oil is that ok, cause i know all the rest of them are bad ie.. Castrol synthetic, Vavoline synthetic.

 

You're off-topic. I say this because you've brought up another topic that does not need to be discussed again.

Any further posts about synthetic vs. dino will be deleted.

As to the original topic, for a seldom-driven car I think annual oil changes is fine.

Dave

 

Ya my question isn't synthetic vs. dyno.

I just haven't had the time and my car is garaged with a cover on it so it really doesn't accumulate any moisture.

My main question was that do you guys think it does any harm since I haven't changed my oil in a year and I have my car garaged with Red Line Synthetic. I only do freeway driving too when I drive it every 3 weeks. Doesn't sound like the oil breaks down because of time.

 

You can still have moisture in your engine, cover or no cover. But in regard to your larger question it's unlikely you've done any measurable harm. You say you drive it every three weeks so that keeps things lubricated. The engine also generates acidic combustion by-products, but the oil works to neutralize these. Given that there are few oil related rotary engine failures I don't think your year old oil has done any measurable or observable harm. Oil will oxidize over time. But in theory, if you tore your engine down at 6 months and then again at 1 year I doubt you'd find any measurable difference between the two.

 

Just to add a little......oil changes in cars are needed not so much because of "oil breakdown" but rather to remove the impurities that have accumulated in the oil.
Over time there is fuel dilution of the oil and the accumulation of combustion by-products which contribute to the formation of sludge inside the engine.

A synthetic oil in a car driven low miles over the course of 1 year is unlikely to have done any harm. I wouldn't let it go 2 or 3 years though.

 

Me personaly, I'd change it, run it for 20 minutes, then dump that oil and change it again since it sat so long.

I'm Mr. OverKill though.

 

The other primary factor in oil change interval is cold starts. in piston engines, this is when the most contamination happens to oil. I am pretty sure it will be similar it a rotary.

so for someone that drives 2 miles to work will have essentially the same amount of wear after 3 months as someone that drives 15 miles to work, since the number of heat cycles will be the same and the number of cold starts.

 

Since your car remains covered, in a garage, I can't see how the oil could possibly become contaminated by moisture, or anything else. No reason to change it.

When was the last time ANYONE had an oil related engine problem??? Our engines do not fail because of oil problems. They fail due to seal problems. Your 500 mile oil is fine.

 

You know I was wanting to ask the same question. If I put fresh oil in the car and park it for a year while deployed and the car sits for a year. Will the oil be bad?

But back to your question, I know the Ford dealership back home in kansas wont change the oil until the car reaches 3000 miles even if it overa year pass due under the free maintance plan.

 

How badly does your oil stink of gas? For some, it is strong, others it is none. This dilutes the oil. Gas isn't a lube.

 

Water vapor is a by-product of combustion. That's why you see it coming out your tailpipe when you first start your car, and why your exhaust system generally rots from the inside out.
Through combustion blow-by a certain amount of this will get in your oil. If you check another current thread, "Fuel in the oil" you'll see the oil analysis done for one FD owner. Look down the list and you'll see H2O. It's a small amount to be sure, but it's there.

 

No.

That's reasonable. I would agree with it for an FD except that FD's get fuel dilution and you can only change around 3.5 out of the 5 qts at a change.

I think the only way oil could have any effect on the engine is if you ran on a fill of oil for 2999 miles and then let it sit for a year. By 2999 it's getting kinda dirty, and then giving it a year is less good than putting in fresh oil to sit for that year.

Dave

 

Personally, I'd just change it. An oil change only takes 30 minutes or so, and is a good opportunity to get under the car and verify that everything looks OK. I prefer to run inexpensive oil and change it often.

-s-