Thread: Flickering Oil Pressure warning light

Thanks for the comments everyone. I drove to my two nearest garages yesterday - one was closed till mid January, the other did not have a pressure guage that woul fit (access problem not a thread problem). The warning light did not come on while I was driving around even though it did get up to operating temperatures.

I'm using Penrite HPR15 oil. Cost of the oil filters was not a factor so lets forget about that. I may have misunderstood the many posts on oils and oil changing but from what I read I gathered two things:
1.There is evidence that changing the oil filter too often is of no benefit and may even be detramental to engine life.
2. That many believe a 5000Km oil change will enhance engine life.
From this I concluded the best option would be to change the oil and filter at 10,000Km but change the oil only at 5000Km.

I'm not stating a position here, this is merely my interpretation of the collective wisdom of the forum. If you can tell me why this is the wrong thing to do (with a little evidence please) then I'll gladly change my practice. Frank your comments are noted - thank you.
I just want to do the best thing to maintain my Landy.

Changing an oil filter 'too often' (if that is possible) will have no detriment to the engine - air filters are a different thing - and actually they get slightly better as you get more dust in them - to a point obviously - this is what you may have mistaken/misread.

As TANK said if you don't change the filter - then any crud collected by it will be re-introduced into the new oil - making the oil change less effective. Remember there will be about 1 ltr of the old oil in the filter +/-.

Ignoring the cost element as you said, you have the old oil out, to change the filter is easy enough time wise, and no it cannot harm the engine.

Dave, you have concluded incorrectly.

1. Clean oil can never hurt any machinery. Old oil, full of carbon particles, metal particles, etc. That hurts.
2. Change you filter at the same time as your oil, always. See point 1.

Flickering oil pressure lights are a dire warning. DO NOT DRIVE IT.

Shorty.

My flickering oil warning light has mysteriously stopped happening. Yes the lamp is still working - it comes on before starting and if I remove the connector from the pressure switch. I discovered this in my fruitless drive around all the auto shops in Windsor trying to find a replacement switch. Now I have one on order from Graeme Coopers.

Ladas and Shorty - thanks for your replies. You had me worried there for a while as I thought the rumours were true and I really was senile.
BUT having re-read this thread: http://www.aulro.com/afvb/showthread.php't=29264&highlight=filters
There is this comment from Isusurover:

Originally Posted by isuzurover

Oil filters are slightly different. Most modern full flow filters are only able to remove particles down to about 5 microns at best, since they have to retain a high flow rate and minimal pressure drop. They will also increase in efficiency over time...

I also saw a positive answer to this question put by Slunnie (my emphasis):

Originally Posted by slunnie

Also, with centrifuge filtering, is it still beneficial to change the oil at more regular intervals than that recommended due to oil breakdown etc, but just leave the old filters in there.

The discussion was clearly about oil filters at that point, however I didn't pick up at the time that it was referring only to centrifugal filters.

To summarise, my understanding is now that with spin-on cartridge oil filters they should be changed with the oil and the lubrication benefit from changing the oil will outweigh the slight loss in efficiency of the new filter.
Hope that's right.

Near enough Dave. Can't see how a new filter can possibly be less efficient than a used one, as the filter actually becomes less efficient over time as it gets clogged with gunk.
I still recommend changing oil and filters at 5000 Km, air, oil, and fuel. Then again, I live in a dusty environment in the Mallee country of SA. A complete change of brake fluid every 2 yrs, is also a good idea.
Once rode a Yamaha motorcycle, disk brake front end. Very high pressure needed to get any braking force. An older fitter, I worked with told me to completely change the fluid, I did so, and almost went over the handle bars the first time I used the brakes afterwards.
The moral? Clean fluids work, dirty fluids will kill the machine or you or both.

Shorty.

Glad one of us isn't senile (shame it's not me)

And your statement

"the lubrication benefit from changing the oil will outweigh the slight loss in efficiency of the new filter."

Is, in my view - just about spot on.

Originally Posted by DiscoDave

My flickering oil warning light has mysteriously stopped happening. Yes the lamp is still working - it comes on before starting and if I remove the connector from the pressure switch. I discovered this in my fruitless drive around all the auto shops in Windsor trying to find a replacement switch. Now I have one on order from Graeme Coopers.

Ladas and Shorty - thanks for your replies. You had me worried there for a while as I thought the rumours were true and I really was senile.
BUT having re-read this thread: http://www.aulro.com/afvb/showthread.php't=29264&highlight=filters
There is this comment from Isusurover:
I also saw a positive answer to this question put by Slunnie (my emphasis):
The discussion was clearly about oil filters at that point, however I didn't pick up at the time that it was referring only to centrifugal filters.

To summarise, my understanding is now that with spin-on cartridge oil filters they should be changed with the oil and the lubrication benefit from changing the oil will outweigh the slight loss in efficiency of the new filter.
Hope that's right.

Dave, Oils ain't Oils nowadays, the act of changing oils every 5000klms is unecessary with todays Modern Oils, years back I worked as a courier for Grace Bros. and they had an oil testing lab at the Warehouse/Garage (removal trucks), I had a Falcon Panel Van 5Lt. V8 and used to change the oil every 5000klms because of the heavy traffic, stop, start driving, I had my oil (Castrol) checked by them and the 5K oil was as good as the day I put it in, had it tested at 10K and it was still in great condition, the oil was changed at 15K even though the Lab test showed it was still good for another 5K. I then converted to straight LPG and my oil changes went to 30K. Today Oils are even better, esp. the Synthetics, but expensive, I use Castrol Magnatec in my 4Lt. Disco and have no Qualms about changing it every 10K, there are still Labs around that will test your oil and give you a report, they can tell what parts of the engine are wearing by the types of microscopic metalic particles in your oil, i.e. bearings, camshaft, crank, pistons and rings, all different types of metal.
If I was you Dave I would be buying a proper oil pressure gauge and fitting that, your standard oil pressure switch operates an Idiot light to warn of low oil pressure, a guage will show what is happening all of the time, Regards Frank.

Interestingly, Redline Lubricants recommend that if you use their engine oils, which can last up to 30,000 klms or more that you STILL change the oil filters as per the manufacturer's schedule, i.e. LR say oil filter every 15,000 - I say every 5,000 klms.

So here we have a situation where the OIL is kept longer but FILTERS are changed more frequently than yhe oil.