Could some fuel additives lengthen fuel pump life?

[K-Man]

In a search, this topic doesn't seem to have been addressed here before.

On most modern vehicles replacing the fuel pump after it fails is a hassle. For example, you might have to take the bed off a pickup to get to the pump.

I'm wondering: could regular "maintenance" use of a lubricative fuel additive such as Marvel Mystery Oil or Schaeffer's Soy Ultra (or several other examples) help lubricate the pump and lengthen its life? Is anyone here doing this? Anyone have any results either way?

I'm thinking in particular of the additive possibly lubricating the pump shaft bushings to avoid/delay eventual seizure and failure of the pump.

 

[kschachn]

How many fuel pumps have you had fail? I had one die once in my old BMW, but that was it. Even my 30 year old Accord and the 27 year old Sienna have not.

 

[JavierH19]

The only one that has shown to do something is 2 cycle oil because it adds some lubricity and is known to quiet old worn pumps but that doesn't mean it's guaranteed to extend their life as there's no way to prove when the pump would have died without it or that noise reduction means less wear.

Different motor oils can make an engine run louder or quieter and although it's enticing to extrapolate that reduced noise as reduced wear and increased life even i'll admit there's almost nothing of substance there. Though I seek oils that are quieter running because I simply like a quieter sounding engine though a lounder running oil like mobil 0w-40 shouldn't cause any harm over a quieter oil like pennzoil platinum euro or quaker state euro as those shouldn't dramatically increase engine life either because they make the engine makes less noise.

There is also no study to point to into the benefits or drawbacks of added lubricity in fuel pumps but at worst it causes no harm. Though there are cases of 2 cycle engines being ran on a very light 200:1 and not dying after hours of use as even that tiny bit of added lubricity does a lot compared to having no oil in the gas and have the engine seize in a couple minutes but one shouldn't extrapolate that difference in added equipment longevity to fuel pumps. If you want to experiment you can use any tcw3 2 cycle and do a richer than normal 300:1 without harm either. Does your pump make noise?

I run 2 cycle in my vehicles even my 2021 escalade still under warranty because why not. it's a free country. It quiets the fuel injectors a little but the engines feel smoother running to me. In my old trucks I like to think they add a few psi of compression because of slightly better ring seal and there's good debate on the rings being better lubricated during cold starts and the compression stroke when the piston goes up but there's no proof to show that they dramatically increase engine life either. Also I need an excuse to use my many gallons of tcw3 boat oil because I have no boat.

 

[thastinger]

I've had two go out, both at around 160-175K, but have others that are original pump at 200K.

 

[RooflessVW]

I think it depends on the mode of failure.

I would think that typically the motor or other electronics fail, not the actual pumping mechanism.

 

[Nessism1]

Sounds like a case of overthinking. The only fuel pump failure I've experienced was because of a check valve failure.

 

[wings&wheels]

An vintage diesel injector pump running current fuels probably, but I cannot see any difference for any common modern vehicle.

 

[RooflessVW]

An vintage diesel injector pump running current fuels probably, but I cannot see any difference for any common modern vehicle.

Modern diesels benefit from an additive as well. Not so much for the lift pump, but for the high pressure fuel pump.

 

[Hohn]

In a search, this topic doesn't seem to have been addressed here before.

On most modern vehicles replacing the fuel pump after it fails is a hassle. For example, you might have to take the bed off a pickup to get to the pump.

I'm wondering: could regular "maintenance" use of a lubricative fuel additive such as Marvel Mystery Oil or Schaeffer's Soy Ultra (or several other examples) help lubricate the pump and lengthen its life? Is anyone here doing this? Anyone have any results either way?

I'm thinking in particular of the additive possibly lubricating the pump shaft bushings to avoid/delay eventual seizure and failure of the pump.

You are assuming that a likely cause of pump failure is a wear mechanism where fuel lubricity is relevant.


Most fuel pump failures are electrical in nature now, not mechanical. Once all the fuel pumps were moved to the tank where they are 1) protected from vibration, 2) cooled, and 3) lubed (even if by fuel) they tend to live long happy lives.

My testing with brushed DC fuel pumps that were (diesel) fuel-lubed showed that brush wear was mostly a function of motor load (current draw) which in turn was a function of restriction.

So at long as the filters weren't plugged or excessively restricted, even a cheap brushed DC roller vane pump of the kind commonly used for in-tank pumps will last a long, long time-- over 12,000 hours in some of my testing. Even if you are only averaging 30mph in the car, that's 360k miles.

The brushes and not the bearings or anything where the life limiting factor. If you are using a brushless DC motor, then 20k hours or more are possible.

Some solenoid pumps on the market have 50k hour life ratings.

 

[Thebigm]

In a search, this topic doesn't seem to have been addressed here before.

On most modern vehicles replacing the fuel pump after it fails is a hassle. For example, you might have to take the bed off a pickup to get to the pump.

I'm wondering: could regular "maintenance" use of a lubricative fuel additive such as Marvel Mystery Oil or Schaeffer's Soy Ultra (or several other examples) help lubricate the pump and lengthen its life? Is anyone here doing this? Anyone have any results either way?

I'm thinking in particular of the additive possibly lubricating the pump shaft bushings to avoid/delay eventual seizure and failure of the pump.

02 Camry still on original pump

 

[kschachn]

You are assuming that a likely cause of pump failure is a wear mechanism where fuel lubricity is relevant.


Most fuel pump failures are electrical in nature now, not mechanical. Once all the fuel pumps were moved to the tank where they are 1) protected from vibration, 2) cooled, and 3) lubed (even if by fuel) they tend to live long happy lives.

My testing with brushed DC fuel pumps that were (diesel) fuel-lubed showed that brush wear was mostly a function of motor load (current draw) which in turn was a function of restriction.

So at long as the filters weren't plugged or excessively restricted, even a cheap brushed DC roller vane pump of the kind commonly used for in-tank pumps will last a long, long time-- over 12,000 hours in some of my testing. Even if you are only averaging 30mph in the car, that's 360k miles.

The brushes and not the bearings or anything where the life limiting factor. If you are using a brushless DC motor, then 20k hours or more are possible.

Some solenoid pumps on the market have 50k hour life ratings.

Thanks for that.

 

[walterjay]

I have used Marvel Mystery Oil in my small JD tractor which has an electric fuel pump. I has made a remarkable difference in the fuel pump sound, very much more quiet. Whether or not it makes a difference in longevity I do not know.

 

[kschachn]

I have used Marvel Mystery Oil in my small JD tractor which has an electric fuel pump. I has made a remarkable difference in the fuel pump sound, very much more quiet. Whether or not it makes a difference in longevity I do not know.

Interesting, I can’t even hear my pumps unless it’s dead quiet and I hear it run without the engine. I didn’t know about tractors like that.

 

[Chris142]

Usually the brushes in the motor wear out. Nothings going to prevent that

 

[skyactiv]

The only additive you need is a OBDII dongle in your vehicle. My wife was far from home years ago when the high pressure fuel pump died on a VW GTI I once owned. https://bobistheoilguy.com/forums/threads/replaced-the-high-pressure-fuel-pump-on-my-gti.287965/