458 Fuel System Cleaner

BG44K Platinum then Techron injector cleaner every 3-6 mos worked for me.

 

These don't do anything

 

If you're going to use it, use the supplied funnel in the toolkit to get it into the fuel tank. Any other funnel will damage the cap-less fuel filler tube. (I learned the hard way.)

 

What problem are you trying to solve

Do you think this is something that's just "good to do"?

Unless you live in a really ****ty country with really bad fuel, you're going to be getting a good detergent package wherever you fill up with premium fuel.

458 has a direct injection engine so nothing you do in the fuel system will help with intake valve carbon buildup

For that you'll need to do a physical cleaning of the intake valves (remedial works) or install a catch can (preventative works).

As for the injectors themselves, if you're having issues with them, chances are they'll need to be replaced and no amount of cleaning would fix them.

Fuel system cleaning additives in a bottle are really only appropriate for use in old port injection engines AND bad fuel which don't have enough of these additives to begin with.

 

I was having fuel residual on oil analysis. I tried the above to see if it made any difference in the fuel contamination in the oil hopefully helping with leaking injectors after shutdown etc. Will know in a few weeks after oil change. Car runs fine however. FWIW.

 

That's not where fuel contamination comes from

Fuel contamination in oil is an indication of poor ring seals. Don't get too scared, on warm up all engines will have poor sealing. This is one of the reasons why short trips are terrible for engines, before they get a chance to warm up the piston rings aren't "in spec". It's also wone of the reasons why reving your engine like a nutter right after starting the engine is stupid.

If you have excessive fuel contamination in your oil AND you're doing mainly long trips and driving lightly during warm up, THEN you should be concerned because that's the use case where you shouldn't have very much fuel contamination. If you also have oil consumption issues (burning oil) then you almost certainly have a piston ring issue.

 

• change your oil every year or like every 5-7k miles using good oil (the recommended stuff from shell isn't bad but there are also better options out there)
• use the best fuel you have available to you
• stay on top of your other service items (plugs, coolant, transmission/gear fluids, etc.)
• don't beat on the car during warm up phase (get oil temp to 70c before you start to beat on it, stay under 4k rpm until then, oil temp is a proxy for engine block temperature, you want the block/pistons to be close to operating temperature before you really add load or revs), where I live that's about 1km of driving after I leave my parking lot but that depends a lot on climate, there's a water and oil temp on the left hand screen so use it
• don't lug your engine (transmission in auto & sport tends to downshift on coastdown really low like sub 2000rpm especially if you were not driving briskly before that, this in and of itself isn't an issue but if you then go and accelerate you can accelerate quite hard without the transmission downshifting automatically, that's not really good for any engine). Engines, especially performance engines don't "like" to be baby'd. NA engines are less succeptible to damage from lugging compared to turbocharged engines but it still isn't good to try to develop a lot of torque at low engine revs.

 

Compressions were fine on leak down testing @ 35K mi with plug change last year. No Oil consumption, I never rev it after startup. That where most wear occurs at startup as you know. We'll see what this years oil analysis shows in a few weeks. So far not really a big issue with the engine. Fuel contamination was 2% or less if IIRC. Usually when I drive it weekly I do about 20 miles plus and give it plenty of time to warm up. Also put it away hot without much idling to keep condensation at a minimum. Electronics is another story.

 

You're probably fine

Fuel will make it's way into the crankcase (and oil into combustion chamber) even on a "normal" in spec engine, piston rings aren't perfect and there always is a bit of exchange between these volumes

Please do update after your oil analysis

 

i would do chevron techron additive or redline fuel inj cleaner

 

That information is inaccurate. You do however need to select the shop to do the work carefully. There are lot's incorrect machines and invalid procedures being used by 80% of the shops to clean GDI/Piezo injectors. There are however a few shops with legitimate equipment and techniques to resolve issues. Some better than others.

 

Yeah but what I mean is that any issue presenting on an DI high pressure injector will not be solved by simply using an off the shelf fuel detergent

Sure you can get faulty injectors rebuilt or reconditioned, I don’t mean to say all issues must be resolved via replacing the item

 

In addition to what KnifeEdge2k1 said, and I know your intentions are good regarding preventative maintenance, additives aren't always compatible with the hoses, seals and other elastomers in the fuel system. You may end up doing more harm than good.

 

Yes understood, I misunderstood. You are correct on fuel injector cleaner additives, especially with GDI injectors. Pintle clogging/blockage internally for example.

 

Don’t think so

ethanol in gasoline has been around for a while (70s) and whatever detergents that may be useful in this use case is in the fuel already

ethanol being corrosive tends to be more of an issue in much older cars, anything made in the past half century had these in mind already

granted ethanol as an additive is much more common now but unless you’re putting e85 in the tank AND have a leaky fuel system to let moisture in AND live in a humid environment AND leave the car for months at a time then you should be ok

if you do let the car sit for multiple months then you should consider some type of additive formulated specific for this purpose but the better solution is to go drive your cars, don’t let em sit!!

I understand if you live in a super cold climate it’s not really feasible, that’s something I’m thinking about for when I go back to Canada too