Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

Posted

I ran out of fuel yesterday just as I was pulling into the gas station LOL. :rolleyes:

After the fill up, I had to crank the engine for quite a bit to get the car going, I guess I had nothing but air in the fuel lines, but now the car is hesitating quite a bit and idling rough too, I've driven it for over 1 hour since, and it still does that. At WOT, it behaves ok, but if I'm just cruising with traffic flow, or want to accelerate slowly it sputters.

Did I get some crud from the bottom of my fuel tank into the injectors?

Should I use one of those bottles of injector cleaner?

My car is Supercharged (EVO) does that make a difference?

Any prefered brand?

  • Admin
Posted

Running out of fuel in these cars is not good.

Try disconnecting the battery for a few minutes to reset the DME. Then you will need to drive it some to re-learn the DME programming.

Posted
Running out of fuel in these cars is not good.

Try disconnecting the battery for a few minutes to reset the DME. Then you will need to drive it some to re-learn the DME programming.

Sounds good I'll give it a try.

So no cleaners huh?

Thanks Loren.

Posted

The Chevron fuel cleaner with Techron is very good, and reported to be Porsche approved. Regardless, you should also change the oil after using a fuel cleaner.

Posted
The Chevron fuel cleaner with Techron is very good, and reported to be Porsche approved. Regardless, you should also change the oil after using a fuel cleaner.

Why?

The theory is that the fuel cleaner dislodges small particles from whatever areas it washes down and all of those contaminants end up in the oil. YMMV.

Regards, Maurice.

Posted
The Chevron fuel cleaner with Techron is very good, and reported to be Porsche approved. Regardless, you should also change the oil after using a fuel cleaner.

Why?

The theory is that the fuel cleaner dislodges small particles from whatever areas it washes down and all of those contaminants end up in the oil. YMMV.

Regards, Maurice.

So, IF that theory was true, then that means that gas regularly gets into the oil too. And if that was the case, your engine would grenade in a very short time. :lol:

Using a fuel additive does not effect the oil and there is no need to change the oil after using it.

Posted
Why?

Hi 1999Porsche911, everything I have read from the "oil experts" recommends using a fuel cleaner just prior to your oil change. I think the main issue is the fuel cleaner disrupts the oil viscosity.

Posted (edited)
Why?

Hi 1999Porsche911, everything I have read from the "oil experts" recommends using a fuel cleaner just prior to your oil change. I think the main issue is the fuel cleaner disrupts the oil viscosity.

First of all, as I said earlier, if fuel injector cleaner or the dirt is washes away was able to get into the oil, then your gas would also get into the oil. You would then have a major problem with your engine and any investment in injector cleaner would be best used by putting it into a cookie jar to help defray the cost of a new engine which is sure to be needed.

You may be confusing a gas additive with an oil additive.

Edited by 1999Porsche911
Posted

I have to agree, fuel additive should not have any effect on the oil! It is being introduced in the combusion portion of the engine. If anything dirt should be exited via the exhaust, or be burnt up under the combustion process. If there was any dirt introduced into the oil via blow by it would be so small the oil could handle with no problem, based on it's additive properties. Now if one was to do a major soak as some do with Seafoam, which i would not recommend then yes you need to change your oil because the cleaner will dilute the oil.

In the Techron case added to the fuel, there is not enough volume to do that by any means!

BTW all fuels contain detergents by law!

So add the techon if you want and don't worry about the oil until due for it's normal change interval.

Posted
Why?

Hi 1999Porsche911, everything I have read from the "oil experts" recommends using a fuel cleaner just prior to your oil change. I think the main issue is the fuel cleaner disrupts the oil viscosity.

First of all, as I said earlier, if fuel injector cleaner or the dirt is washes away was able to get into the oil, then your gas would also get into the oil. You would then have a major problem with your engine and any investment in injector cleaner would be best used by putting it into a cookie jar to help defray the cost of a new engine which is sure to be needed.

You may be confusing a gas additive with an oil additive.

On the issue of "gas getting into the oil", read Jake Raby's comments in the December '08 issue of Porsche Excellence magazine. That is one of his reasons for recommending more frequent oil changes than Porsche recommends.

Regards, Maurice.

Posted
You may be confusing a gas additive with an oil additive.

No confusion here. Just a different and more conservative approach. Not an issue of "right" or "wrong". Everything I have read recommends an oil change after the use of a fuel cleaner. The operative word being"recommended".

Posted (edited)
You may be confusing a gas additive with an oil additive.

No confusion here. Just a different and more conservative approach. Not an issue of "right" or "wrong". Everything I have read recommends an oil change after the use of a fuel cleaner. The operative word being"recommended".

I would love some examples of what fuel additive companies recommend changing your oil in relationship to using their products. I have never come across any in the past 40 years. As a matter of fact, many of them recommend using the additive every 1000 miles or so. That would be alot of oil changes.

Edited by 1999Porsche911
Posted

Well I did not add any fuel additives, but instead disconnected the positive terminal of the battery last night.

Reconnected it this morning, and tried to go to work, but the car was idling real rough and died on me a couple of times, before I even reached the end of the cul-de-sac.

Made a U-turn and headed back to my garage keeping the RPMs high to prevent the engine from sputtering to death again, then got in my other car and went to work.

I started the car again this evening, and after bellowing huge clouds of smoke it was idling very rough again, I stayed in the car keeping the RPM in the 3K range, it did not look like the car was appreciating this.

Eventually it got a little bit smoother, but not normal by any means.

I am debating wether to do the fuel additive thing or taking the car to an Indie tomorrow.

Posted

One of the main problems when running out of gas is that all the "gunk" in your fuel tank that has settled in area below the fuel supply begins going into the fuel line to the engine. That will sometimes clog the fuel filter and starve the engine. I would check out the fuel filter and replace it, if it is not too expensive to just experiment. Anyway, all engines new a new fuel filter sometimes and you would be okay in doing it. Hope this helps.

04 C4S CAB

Posted

In graduate school, I had an engineering internship at an automotive proving ground. Among other things, I had some involvement in on-going testing being conducted by a major petrochemical company. Controlled, on-road testing using production vehicles/engines. Different fuels, different additives. Intake and heads removed and torn down at regular intervals. Valves weighed before and after. Deposits and oil analyzed. Etc.

From what I recall in college, internal combustion engines are not 100% efficient and not all of what occurs during strokes 2 and 3 exits through the exhaust port(s) in stroke #4. I've also noted that oil analyses include the amount of water, fuel, insolubles, and the like. For example, Blackstone has criteria for fuel at <2.0% and water at <0.1%. Their criteria for these are not 0.00% (like it is for glycol).

Thus, I'm not convinced that unburned fuel and other contaminants from the combustion process can't possibly get into motor oil under normal circumstances. It seems to me that how much this actually occurs has changed over the years as engines have tightened-up, component tolerances have improved, and the efficiency of combustion has increased with design enhancements like direct injection and advanced engine management. It definitely seems debatable how much it really matters whether you change your oil after running an additional fuel detergent. After all, wouldn't variables such as the condition of the oil itself, the effectiveness of the detergent, the type and amount of build-up, and the condition of the engine (i.e. pistons, rings, cylinders) factor into the equation?

Anyway, what guides me in my own vehicle maintenance regimen extends from my experience about 15 years ago during my internship. Just before scheduled oil changes, I run a tank of fuel with a good dose of Techron. I don't think it is necessarily misguided or overly conservative to advise others of the same.

Posted
In graduate school, I had an engineering internship at an automotive proving ground. Among other things, I had some involvement in on-going testing being conducted by a major petrochemical company. Controlled, on-road testing using production vehicles/engines. Different fuels, different additives. Intake and heads removed and torn down at regular intervals. Valves weighed before and after. Deposits and oil analyzed. Etc.

From what I recall in college, internal combustion engines are not 100% efficient and not all of what occurs during strokes 2 and 3 exits through the exhaust port(s) in stroke #4. I've also noted that oil analyses include the amount of water, fuel, insolubles, and the like. For example, Blackstone has criteria for fuel at <2.0% and water at <0.1%. Their criteria for these are not 0.00% (like it is for glycol).

Thus, I'm not convinced that unburned fuel and other contaminants from the combustion process can't possibly get into motor oil under normal circumstances. It seems to me that how much this actually occurs has changed over the years as engines have tightened-up, component tolerances have improved, and the efficiency of combustion has increased with design enhancements like direct injection and advanced engine management. It definitely seems debatable how much it really matters whether you change your oil after running an additional fuel detergent. After all, wouldn't variables such as the condition of the oil itself, the effectiveness of the detergent, the type and amount of build-up, and the condition of the engine (i.e. pistons, rings, cylinders) factor into the equation?

Anyway, what guides me in my own vehicle maintenance regimen extends from my experience about 15 years ago during my internship. Just before scheduled oil changes, I run a tank of fuel with a good dose of Techron. I don't think it is necessarily misguided or overly conservative to advise others of the same.

Q:

Very level-headed analysis. It comports with Jake Raby's observations where the condition of the engine vis-a-vis the pistons, rings, cylinders, valve guides and valve stems start to become a factor due to wear.

Regards, Maurice.

Posted
In graduate school, I had an engineering internship at an automotive proving ground. Among other things, I had some involvement in on-going testing being conducted by a major petrochemical company. Controlled, on-road testing using production vehicles/engines. Different fuels, different additives. Intake and heads removed and torn down at regular intervals. Valves weighed before and after. Deposits and oil analyzed. Etc.

From what I recall in college, internal combustion engines are not 100% efficient and not all of what occurs during strokes 2 and 3 exits through the exhaust port(s) in stroke #4. I've also noted that oil analyses include the amount of water, fuel, insolubles, and the like. For example, Blackstone has criteria for fuel at <2.0% and water at <0.1%. Their criteria for these are not 0.00% (like it is for glycol).

Thus, I'm not convinced that unburned fuel and other contaminants from the combustion process can't possibly get into motor oil under normal circumstances. It seems to me that how much this actually occurs has changed over the years as engines have tightened-up, component tolerances have improved, and the efficiency of combustion has increased with design enhancements like direct injection and advanced engine management. It definitely seems debatable how much it really matters whether you change your oil after running an additional fuel detergent. After all, wouldn't variables such as the condition of the oil itself, the effectiveness of the detergent, the type and amount of build-up, and the condition of the engine (i.e. pistons, rings, cylinders) factor into the equation?

Anyway, what guides me in my own vehicle maintenance regimen extends from my experience about 15 years ago during my internship. Just before scheduled oil changes, I run a tank of fuel with a good dose of Techron. I don't think it is necessarily misguided or overly conservative to advise others of the same.

The gasoline you put in your car has the same chemicals as these after market additives do. So I wonder why you don't change your oil after every fillup? There is NO WAY, I repeat, NO WAY for any additive to get from the cylinders into the oil without also having gasoline get into the oil. If this is the case, your engine is doomed anyway.

But, marketting is very powerful on some people.

Posted
In graduate school, I had an engineering internship at an automotive proving ground. Among other things, I had some involvement in on-going testing being conducted by a major petrochemical company. Controlled, on-road testing using production vehicles/engines. Different fuels, different additives. Intake and heads removed and torn down at regular intervals. Valves weighed before and after. Deposits and oil analyzed. Etc.

From what I recall in college, internal combustion engines are not 100% efficient and not all of what occurs during strokes 2 and 3 exits through the exhaust port(s) in stroke #4. I've also noted that oil analyses include the amount of water, fuel, insolubles, and the like. For example, Blackstone has criteria for fuel at <2.0% and water at <0.1%. Their criteria for these are not 0.00% (like it is for glycol).

Thus, I'm not convinced that unburned fuel and other contaminants from the combustion process can't possibly get into motor oil under normal circumstances. It seems to me that how much this actually occurs has changed over the years as engines have tightened-up, component tolerances have improved, and the efficiency of combustion has increased with design enhancements like direct injection and advanced engine management. It definitely seems debatable how much it really matters whether you change your oil after running an additional fuel detergent. After all, wouldn't variables such as the condition of the oil itself, the effectiveness of the detergent, the type and amount of build-up, and the condition of the engine (i.e. pistons, rings, cylinders) factor into the equation?

Anyway, what guides me in my own vehicle maintenance regimen extends from my experience about 15 years ago during my internship. Just before scheduled oil changes, I run a tank of fuel with a good dose of Techron. I don't think it is necessarily misguided or overly conservative to advise others of the same.

The gasoline you put in your car has the same chemicals as these after market additives do. So I wonder why you don't change your oil after every fillup? There is NO WAY, I repeat, NO WAY for any additive to get from the cylinders into the oil without also having gasoline get into the oil. If this is the case, your engine is doomed anyway.

But, marketting is very powerful on some people.

Is this marketing comment directed at me? I don't have a perspective here from anyone's marketing. --Brian

Posted
Is this marketing comment directed at me? I don't have a perspective here from anyone's marketing. --Brian

Dude, relax....it is not directed at you. You are the one that suggested changing the oil after fuel treatment...there is no relationship between the two systems (if there is you are in trouble). We are just saying that it is a marketing ploy to suggest changing the oil after fuel treatment (i.e., it is bs to do this).

Posted
Is this marketing comment directed at me? I don't have a perspective here from anyone's marketing. --Brian

Dude, relax....it is not directed at you. You are the one that suggested changing the oil after fuel treatment...there is no relationship between the two systems (if there is you are in trouble). We are just saying that it is a marketing ploy to suggest changing the oil after fuel treatment (i.e., it is bs to do this).

I understand that text can be read different ways, but I’m very relaxed here. After all, it’s the holidays, I’m on vacation, and this subject isn’t exactly politics or religion...so no worries. In any case, I jumped into this thread at post #18 and please note it wasn’t me that suggested anything in the first place. I simply tried to provide a viewpoint of the merits of both sides of this topic based on my education and experience, for whatever it is worth.

I hope we can start with an agreement that the combustion process within automotive engines isn’t 100% thorough and that some unburned fuel is par for the course. Obviously this has vastly improved over the years as intake and cylinder head designs have been refined, fuel atomization and spark delivery have been improved, and engine management has been optimized. In addition, water and soot are by-products of combustion. Not all of the gases and solids exit the exhaust port(s). Some exhaust is forced past the piston rings into the crankcase, a condition known as blow-by. For many engines, especially those with variable valve timing, some exhaust is also forced back into the intake system due to slight overlap between the intake and exhaust valve cycles, often eliminating the need for a separate EGR system.

A certain amount of blow-by is a given and acceptable even when the engine is shiny and new. It varies depending on the engine and application due to design specifications and manufacturing tolerances for things like piston ring groove clearances and end gaps. The sealing between piston and cylinder wall generally gets worse with deformation and wear. Crankcase pressure increases due to the blow-by and has been managed for over 50 years by PCV systems and the like--including the troublesome crankcase ventilation system for many of us with M96 engines. (Any failed external oil separators out there?) Oil sprayed under the pistons to line the cylinder walls with every stroke is a cause of oil consumption within the combustion chamber, the amount depending on many factors such as the condition and use of the engine. Thus, the interface between the crankcase and the combustion chamber is not exactly an impermeable barrier.

Anyway, just considering blow-by, it’s sure not fresh, particle-free country air getting past the piston rings into the crankcase that gets managed by the crankcase ventilation system. Water, fuel, soot, etc. get into the sump; certain amounts are perfectly normal. I just don’t see how that can be so adamantly denied. Used oil analyses right here on these boards show the presence of fuel and water in low-mileage M96 engines for which Blackstone labs spells out maximum reference levels. Too much fuel or any other contaminant in the oil can spell doom for many reasons; no disagreement there. That’s why mechanical and electronic systems, along with regular maintenance such as oil changes, are in place to manage it.

The discussion here early on centered around whether the deposits that get cleaned out of the intake system and combustion chamber by additional fuel detergents can get into the oil and necessitate an oil change. My position IS NOT that you should change your oil after running a fuel system additive. My position IS that it doesn’t hurt to do so (within reason) and it depends on many factors whether it makes a difference. If you want to change your oil after running a bottle of Techron or something, it’s probably overkill and generally unnecessary especially with today’s engines and consistent use of quality fuel. But, based on my knowledge and experience with fuel and additive testing, it’s just not outright BS to think it might be a good idea in certain circumstances. I know what I saw happen to the oil in some of the tests, and it wasn’t pretty.

Happy Holidays and let’s hope for a better 2009. Take care,

--Brian

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.