stop/start oil filtering question

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Not sure if this is in the correct section or not but here it goes. The other day at a traffic light I began to think of how many cars have stop / start systems. Does anyone think that vehicles with stop / start systems have less time spent with their oil being run through the filter compared normal filtering at stop lights? One would think the bypass valve plays its roll with most cars around 1500 rpm. Thoughts anyone?
 
Its not filtering, but the engine isn't running either, so its a wash.

Doubt any bypassing is happening. Oil filters rarely clog up requiring bypassing. There are spiking bypass events on starting on a very cold morning, but thats another subject.
http://www.corvetteactioncenter.com...h-new-oil-pump-control-systems-1363.html for a discussion about bypass events, and I think they are talking about start-up cold, very cold.
 
How much stress do you put on other parts of the engine?
I assume the start/stop is for fuel savings ...
Is it a popular thing now? I haven't been following it.
 
The filter isn't going to bypass with warm to hot oil when the engine starts up again and you cruise off normally down the road. It might open very briefly if you let it restart with the gas pedal smashed to the floor so the engine hits redline in 1 second or less. Who's going to do that?
eek.gif
 
Well, if the engine is not running then the oil is not being pumped through the filter. When it runs the oil circulates normally.

Could the op clarify the question?
 
Originally Posted by 1978elcamino
One would think the bypass valve plays its roll with most cars around 1500 rpm. Thoughts anyone?


I'm trying to understand where this thought came from.

Sounds like you believe the filter bypass valve is somehow affected by engine oil pressure. It's not.
 
Originally Posted by PimTac
Well, if the engine is not running then the oil is not being pumped through the filter. When it runs the oil circulates normally.

Could the op clarify the question?

I wonder if there is any additional stress on the filter media? With stop/start the oil flow is being stopped and started everytime the car comes to a stop, then restarts time and time again. Which is totally different than a car starting and being shut off once it reaches its destination.
 
It's starting up at idle speeds. Hardly any sress (ie, delta-p) on an oil filter under those conditions once the oil has warmed up some.
 
Originally Posted by ZeeOSix
It's starting up at idle speeds. Hardly any sress (ie, delta-p) on an oil filter under those conditions once the oil has warmed up some.


Thanks. I was wondering if it repeating hundreds if not thousands of times during an OCI might have an impact? EG: More prone to possibly tearing?
 
Originally Posted by demarpaint
Originally Posted by PimTac
Well, if the engine is not running then the oil is not being pumped through the filter. When it runs the oil circulates normally.

Could the op clarify the question?

I wonder if there is any additional stress on the filter media? With stop/start the oil flow is being stopped and started everytime the car comes to a stop, then restarts time and time again. Which is totally different than a car starting and being shut off once it reaches its destination.



I would not think so but I'm not a engineer. The filter will be full of oil so pressure wise I can't think of any stress or pressure that would occur. Interesting thought though.

I'm sure the auto engineers thought of everything when they devised these systems.
 
Originally Posted by demarpaint
Originally Posted by ZeeOSix
It's starting up at idle speeds. Hardly any sress (ie, delta-p) on an oil filter under those conditions once the oil has warmed up some.

Thanks. I was wondering if it repeating hundreds if not thousands of times during an OCI might have an impact? EG: More prone to possibly tearing?


A correctly designed and built oil filter should be able to take the bypass valve setting delta-p stress all day long. Of course not all filters are built equally. But the low delta-p at start-up conditions isn't a real concern, especially a non-concern with warm to hot oil. The only time it might be a concern is when it's well below zero with heavy oil in use during the initial cold start. And in those conditions the bypass valve should prevent any filter damage.
 
stop-start stinks IMO + beside xtra starter + battery issues i read where new "special" bearing material was developed to help with the xtra wear incurred from many restarts. i would only buy a new vehicle with stop-start if it could be easily turned off, + only one with BOTH port + direct injection!
 
Originally Posted by demarpaint
Originally Posted by PimTac
Well, if the engine is not running then the oil is not being pumped through the filter. When it runs the oil circulates normally.

Could the op clarify the question?

I wonder if there is any additional stress on the filter media? With stop/start the oil flow is being stopped and started everytime the car comes to a stop, then restarts time and time again. Which is totally different than a car starting and being shut off once it reaches its destination.

If the oil is at full operating temperature I doubt it makes a difference. I've checked my filter after an oil change and started it up. I felt the filter and it was obviously pulsing rather pumping in a smooth, continuous flow. Plus - I haven't heard of too many electric oil pumps, where most operate based on engine speeds.

Quote
https://www.machinerylubrication.com/Read/29272/oil-filtration-factors
Pump Pulsations and Mechanical Vibrations
Machinery and equipment are subjected to operational vibration and pump pulsations. These conditions can dislodge fine abrasive particles from the filter media and allow this contamination to re‑enter the fluid stream.
 
The bypass valve comes into play if the filter media is clogged or if the oil pressure exceeds a certain value. Start-stop doesn't kick in until the engine is at operating temperature. However, unlike a hybrid that spins the engine at higher RPMs before fuel and spark are introduced, a non-hybrid with start-stop just uses a plain-Jane starter to spin things up. Hot oil, is of course much less viscous than cold oil.
 
Originally Posted by nthach
The bypass valve comes into play if the filter media is clogged or if the oil pressure exceeds a certain value.


More accurately, it's the delta-p across the media. Just to clarify, the engine oil pressure is not what makes a filter bypass valve open.
 
I have one of the start/stop engines. I disable that every time I get in the Jeep and go.
I worry more about the starter being constantly used than the oil filter.
I will gladly give up one mile more per tank and keep my starter from wearing out prematurely
 
Originally Posted by toneydoc
I have one of the start/stop engines. I disable that every time I get in the Jeep and go.
I worry more about the starter being constantly used than the oil filter.
I will gladly give up one mile more per tank and keep my starter from wearing out prematurely


Me too! The Default on it should be off, unless we opt to use it. Not the other way around.
 
Originally Posted by benjy
stop-start stinks IMO + beside xtra starter + battery issues i read where new "special" bearing material was developed to help with the xtra wear incurred from many restarts. i would only buy a new vehicle with stop-start if it could be easily turned off, + only one with BOTH port + direct injection!

What does your opinion have to do with OP's question? More or less another one of your rants. You never addressed the question unless + + + + + +........ is an answer. What's with that anyway?
 
The modern start stop systems are not totally reliant on the starter to restart the engine. There is also some pre-oiling happening just prior to the restart.
 
Originally Posted by PimTac
The modern start stop systems are not totally reliant on the starter to restart the engine. There is also some pre-oiling happening just prior to the restart.


What do you mean by pre-oiling happening Pim?
 
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