Change oil filter only?

[GHW]

This is regarding oil changes on two cars I own, one leaks oil and the other burns oil.
On the average I have to put about a quart of oil in each every 3-4 weeks. I don't have the money to repair either vehicle right now so my question is when I do oil changes should I just replace the oil filter, or should I empty out the remaining oil also?

 

[hate2work]

You should change the oil as well.

 

[Jakegday]

yep, oil as well.

 

[bxd20]

I would say it somewhat depends on:

1. Where is the leak point?
2. How often are you changing the oil?
3. How much of the oil capacity is left if you drain it from the filter? Is that a 25% change, 50%, 80%?

 

[demarpaint]

What is a normal OCI for you? How many months or miles? I might consider extending it, but would change the oil and the filter.

 

[GHW]

The leak is on a GM 3.4 engine, it's leaking from the top of the engine. There is a plug GM put in the hole where the distributor would be installed. I've tried tightening it with no success. And where the plug is I cannot remove it since the corner of the head blocks complete removal.
I change oil three times a year since I rarely drive the vehicle, just mainly to work (approx. 30 miles a week).
Oil capacity is 5.7 quarts and the filter holds about a quart.

 

[demarpaint]

You could probably go to a 1 year OCI then.

 

[GHW]

Thanks. You think a one year OCI would be also be fine for the vehicle that burns oil? That vehicle gets about 150-200 miles put on it a week.

 

[hate2work]

Maybe you could seal around the plug with some high-temp silicone, that might slow/stop the leak.

If you're putting in a quart every month, and only driving 120 miles a month, then I agree with Demar, just change the oil and filter once per year.

 

[hate2work]

Originally Posted By: GHW
Thanks. You think a one year OCI would be also be fine for the vehicle that burns oil? That vehicle gets about 150-200 miles put on it a week.


There are a few things that might slow the consumption. What vehicle/miles/engine?

 

[demarpaint]

I think a 1 year OCI for both vehicles would be fine, but you are leaking and burning a lot of oil. I would do as hate2work suggested. Since that area only leaks while the engine is running a bandaid repair is very possible. Clean the area well, and build some layers of a good RTV sealant around and over it. It might help. A High Mileage oil while might help with leaking and burning issues.

 

[GHW]

The engine that burns oil is in a 1999 Chevy Prizm (1.8L, 4 cylinder), 125k miles.
I use Valvoline HM oil in both vehicles.

 

[Ducati996]

A little more info on your daily driving habits and the condition of the engine would help on a recommendation but here is my 10 cents.
A quart every 4 weeks is 13 qts per year or close to 3 oil changes for your vehicle.
The reason for changing oil is to replenish additives that are used up during use and to remove wear particles, combustion by products, fuel dilution ECT.
If the engine leaks or burns a quart every 4 weeks and it is being replaced then the additive package will be maintained and the impurities will be continually purged from the system preventing damaging accumulations.
There is no little danger changing the oil filter only in this situation.
Checking the oil and rubbing it between your fingers and looking at the transparency and smelling for gasoline or coolant could be your guide. You could do a blotter test but that is better suited for checking soot loading in diesel oil.
Many years ago I was in your situation and acquired a very ratty International ¾ ton pickup which was my daily driver (50 miles a day). It leaked huge amounts of oil. Because of the leak I only added oil and changed the filter. The oil was always clear. The engine was running fine when I parked it.
During the ownership of this vehicle I started working at GE on the Bradley Fighting Vehicle project and operated transmission test cells powered by 500hp Cummins diesels 10 hours a day. I also maintained and performed minor repairs. We had a huge engineering library which included info on maintaining the Cummins engines. I found and still have the booklets that outlined the criteria for determining oil change intervals.
This is the bottom line;
If the engine does not burn or leak oil and requires no make-up oil then the oil & filter must be changed to replenish additives and remove contaminates.
It the engine consumes and/or leaks oil, the oil change intervals can be extended based on the quaintly of oil added, sump capacity and fuel consumed.
Hope this helps!
Ducati 996

 

[lipadj46]

If you are adding a quart every 3 weeks you do not need to change your oil ever.

 

[Nickdfresh]

I'd also change both once a year, just to drain any sediment. I'd also consider bumping the weights assuming you're using 5W-30...

 

[CourierDriver]

Originally Posted By: Nickdfresh
I'd also change both once a year, just to drain any sediment. I'd also consider bumping the weights assuming you're using 5W-30...
I had an oil usage moment on my van sometime back,,change up to 5w40 rotella t6 from 10w30, no more oil usage, and now ive got 270k on the old 318 v8, go figure, but we all have different issues, so far mine is corrected.

 

[GHW]

Thanks for all the advice. I'll try that, cleaning the leaking area up and packing it with silicone to see if it helps.
Also, I'll change to a yearly oil and filter change on both vehicles. Or should I change the filter more often?

 

[bowlofturtle]

I'm on the same boat with my mother's camry. It needs a rear main seal and others. It was leaking about 1qt every 2-3 weeks. I did the valve cover gasket and now its 1qt every months but now she doesn't drive it much. Oil filter is right now top of the engine so i dont have to jack it up. I top off every other week when i get a chance. I drained the oil once last year.

The camry runs on extra oil from all the other cars i maintain, LOL sad but true. It only sees about 5-7k miles a year at most.

 

[mechtech2]

You have a perpetual oil change going on. Both the oil AND filter should last longer.
The oil MUCH longer!