Diesel treatments?? Any good (or bad)?

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bluedragon

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Just noticed on another thread a forum member had tried STP Diesel Treatment. I've often wondered if it was worth adding this to the fuel tank for use with an old engine? It makes lots of claims re: cleaner injectors, easier starting, etc. http://www.stp.eu/uk/products/index.php

Has anyone used this or similar, and found it any good (or bad)?
 
Have a specific job / function in mind / required or just for sake of it ?

Given that diesel is blended product and not pure refined stock as it used to be - who knows which component inhibits what additive etc. ? Get my drift ?
There's enough additives in most diesels today to curl most peoples tootsies up !
 
Just leave well alone and keep your money in your pocket.

As an aside, using STP (though not mentioned by name) invalidates the Yanmar warranty. As you say yours is an old engine.

As to biocides there are two violently opposed schools of thought and both with expert and persuasive opinions.

As Refueler says; It all depends on what you want it to do.

Rejuvenate an old engine : definitely not and probably makes sure your oil-seals leak.
 
Thanks guys. I was just wondering if this stuff was a magic bullet to rejuvenate an old marine diesel...but I guessed that might be wishful thinking /forums/images/graemlins/grin.gif
 
Hey refueler

Chatting to the old man on Toisa Crest. He was saying that on one ship he was on (some time ago) they had bad trouble with the dreaded bug. They fitted fuel purefiers and used monster strength biocide to kill & clear the bug.

Downside of the biocide he stated was that the biocide badly screwed the injectors... they were lasting a week or so before needing to be changed.

Any rumours that biocides can screw your injectors?

Cheers
SmileyG
 
Any rumours that biocides can screw your injectors?

*************************************************

Proper ships ALWAYS have fuel oil purifiers and it is rare for bugs to make it to the engines due to the regime of using purifiers,settling tanks and purifiers. However bugs especially dead ones are very acidic and do play havoc with fuel pump plungers and injector seats and needles if they escape all the way through.

WHat is a bigger concern on ships id getting the critters in the lubricating oil as they can etch the polished bearing surfaces and that is not good for the white metal shell bearings. Engines have been wrecked!!!

Usually the bugs don t make it to the injectors on our boats but if they do then expect to have the nozzles serviced and maybe some extra leakage from the pump plungers.
 
Small marine diesels have remarkable longevity, if fed clean fuel and oil.

So first give your engine an oil and filter change.
Check you have a clean prop and the shaft can be turned easily by hand.
If those are OK, give it about 20' at full power/load and see if it clears the grot, but watch out for overheating.
Get a kind marine mechanic to test compression(s). If those are down you'll know it's old age. If they're down it could be worn bores or (with Yanmar GMs especially) a leaking head gasket.
If all the above work out well, have the injector(s) out and re-set by a good diesel injection shop.

Unfortunately there's no magic bullet for engine rejuvenation. It's a matter of meticulously checking and correcting everything.
 
[ QUOTE ]
Hey refueler

Chatting to the old man on Toisa Crest. He was saying that on one ship he was on (some time ago) they had bad trouble with the dreaded bug. They fitted fuel purefiers and used monster strength biocide to kill & clear the bug.

Downside of the biocide he stated was that the biocide badly screwed the injectors... they were lasting a week or so before needing to be changed.

Any rumours that biocides can screw your injectors?

Cheers
SmileyG

[/ QUOTE ]

I've never heard like it before - so have no idea.

I can say that I was myself subjected to blocked filters / pumps through over-use of injector / system cleaners when I brought boat out to baltic ... I was clearing the red from system. The movement of boat in seaways, the solvents in the cleaner lifted the previously no-problem crud in bottom of tank and bingo ! My tank is a truck mild steel tank and looks 'black' inside ... so no way to have seen the layer in bottom.
Bug killers can either have enzymes or solvents in to try and rid the dead debris of their use. Some are successful - some may not be ... I cannot tell you which as I do not deal in retail additives. When I've offered in past to various that they send samples "at their cost" for testing - nothing ever arrived !

I do use odd additives at times, but sparingly and for specific duties.
 
[ QUOTE ]
Any rumours that biocides can screw your injectors?

*************************************************

Proper ships ALWAYS have fuel oil purifiers and it is rare for bugs to make it to the engines due to the regime of using purifiers,settling tanks and purifiers. However bugs especially dead ones are very acidic and do play havoc with fuel pump plungers and injector seats and needles if they escape all the way through.

WHat is a bigger concern on ships id getting the critters in the lubricating oil as they can etch the polished bearing surfaces and that is not good for the white metal shell bearings. Engines have been wrecked!!!

Usually the bugs don t make it to the injectors on our boats but if they do then expect to have the nozzles serviced and maybe some extra leakage from the pump plungers.

[/ QUOTE ]

When working with Petromin in Saudi - we had one ship that had bug in the main engine lub oil. We had to anchor, drain down the sump. Crew got inside and with brooms were pulling down the coating of the internal walls of the sump. The paint was sliding down the walls like soft treacle. The bugs had got behind it ..
 
[ QUOTE ]
Small marine diesels have remarkable longevity, if fed clean fuel and oil.

So first give your engine an oil and filter change.
Check you have a clean prop and the shaft can be turned easily by hand.
If those are OK, give it about 20' at full power/load and see if it clears the grot, but watch out for overheating.
Get a kind marine mechanic to test compression(s). If those are down you'll know it's old age. If they're down it could be worn bores or (with Yanmar GMs especially) a leaking head gasket.
If all the above work out well, have the injector(s) out and re-set by a good diesel injection shop.

Unfortunately there's no magic bullet for engine rejuvenation. It's a matter of meticulously checking and correcting everything.

[/ QUOTE ]

I'm glad to say that this is pretty much how I do look after my 40yrs old engine. There's nothing actually wrong with it, though I'm sure it doesn't start as easily as new (to be expected) but I just wondered if fuel additives might in general be a help into its old age. The overall view seems to be no...
 
Refueler - a question: is there any evidence (theoretical or practical) that ROAD diesel (or a mix with red) might be a better option for our boat engines in terms of general cleanliness, starting, etc? As I only need about 20L to top-up for the season, it's almost as easy to pop down to Tesco with a can rather mess around with the fuel berth.
 
And Ohhhhh that wonderfull pong of BUGS. Never forget the look on the face of a mate when he complained his hydraulic torque converter wasn t working on his rolling road at his car tuning business! He had drained it out to refill. The smell bought back memories but the look on his face when I told him he had bugs in the system. However MArston Chemicals who do bug treatments for the offshore and marine rescued the situation.. Very distinctive smell!

Beware these bugs of you are a workshop technician as they love the emulsified cutting oils....Lots of lovely oil water interfaces.
 
[ QUOTE ]
Refueler - a question: is there any evidence (theoretical or practical) that ROAD diesel (or a mix with red) might be a better option for our boat engines in terms of general cleanliness, starting, etc? As I only need about 20L to top-up for the season, it's almost as easy to pop down to Tesco with a can rather mess around with the fuel berth.

[/ QUOTE ]

Personally I wouldn't worry about which you use. Red is reducing it's sulphur levels over a period until it will eventually be similar to Road. There is a lot of rubbish talked about bio added to Road and what is in Red. Much of it comes from so-called Industry Experts as well - who drive Desk's not blending ops.

My old 4-107 runs on what I throw at it. I have Road blend (UK / Germany / France ... ) plus Fuel Oil grades FOD etc. for simnilar markets that we blend up. In my boat-store I have 2 40 gal drums that I mix it in ... it can be Road one day or FOD next ... my "special" filtration system then runs it through, it then settles out and I draw of what I need ....

2009AprilPontoonbuilding012-1.jpg


Pump draws fuel through domestic water filter of max 5 micron ... and back to drum. Circulating for period to remove larger sediments / particulates. Let drum settle for period before drawing of direct for boat - NOT through pump etc. As I want any particulate not taken out by filter to settle in bottom of drum below valve take-off.

Neat and works. Normal blend in there ? maybe 10% Kerosine or RT ... 50% gasoil 0.1 / 0.2 Sulphur...... 30% ULSD 30ppm Sulphur or less ...... rest black / poor quality heating oil or MDO.

My Lab test on last batch : THIS IS NOT WHAT WE BLEND FOR MARKET - THIS IS PURELY MY BOAT FUEL ONLY

Density - 0.8416 kg/ltr in vac
Cetane index - 49.1

Distillation:

IBP - 142.3 oC
10% - 204.1 oC
50% - 265.6 oC
90% - 337.2 oC
95% - 351.9 oC
FBP - 364.4 oC

Flash point - 65.0 oC

Sulphur - 0.115 %mass

Water - 0.077 %mass (772 mg/kg)

Sediments by extraction - 0.012 %mass


The only area that is possibly considered high is the sediments at 10x normal. The rest is OK and my engine runs well on it. Bit smoky if I give it the gun !! but generally no problem.

Now "old Chemists" will post and I'm interested in what they think !!
 
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What engine.......and what is wrong....There may be more positive actions than Snake Oil.

[/ QUOTE ]

Nothing wrong Bilgediver. Sabb 8 which has its own special technique for cold-starting anyway (oil injection). Burns clean - no blue or black. No leaks or rust. The oldest spec lube oil I can find, re-con injector a few years back. I just wondered if the snake oil additives were a good idea to keep it purring along for another 40 years!
 
[ QUOTE ]
My old 4-107 is of similar vintage. I do nothing special for it. Starts and runs well.

[/ QUOTE ]Pure nosiness, but is your engine raw seawater cooled, or with a separate heat exchanger? I think the life of our engine will be probably be ended by internal corrosion rather than mechanical wear.
 
[ QUOTE ]
[ QUOTE ]
My old 4-107 is of similar vintage. I do nothing special for it. Starts and runs well.

[/ QUOTE ]Pure nosiness, but is your engine raw seawater cooled, or with a separate heat exchanger? I think the life of our engine will be probably be ended by internal corrosion rather than mechanical wear.

[/ QUOTE ]

Raw water - but now it's in luxury as river is Fresh Water, Baltic is barely Brackish - so after 3x yrs of UK SW - it's now in a less corrosive environment.

Funny thing is the older 4-99 it replaced was heat exchanger equipped. We looked at swapping it over, but HE end cap had crooded away and I'd been surviving with Plastic Metal sealing it up. It worked !! Yes - I know another of my bodges ! /forums/images/graemlins/wink.gif
 
I must admit I use the one found in garages smlar to redex for cars it is a green liquid ad supposed to improve combustion. I also use oil for starting in winter.
 
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