Diesel problem

[Spudwynk]

Looking for some advice on best action to take with potentially dirty fuel / water in fuel

 

We're leisure boaters and we're out the other weekend and the engine almost cut out on us but essentially no more power than tixk over when on full throttle. Made it back to safety. Have had engine serviced, all OK but recommend getting a fuel polish

 

Share all things equal with a fuel polish and will it help me? I've had quotes from around £250 by someone local (Diesel Dave) upwards. Not asked tankbusters yet but understand they are significantly more

 

But once we have the fuel sorted how do we stop it reoccurring? We used plenty of additive and keep tank full in winter. Could the filler cap be leaking water in? Anything else we can check / do to minimise reoccurrence?

 

Thanks

[Tony Brooks]

1. Filler cap leak - yes, very probably.

 

2. Stopping it happening again. The best you can do is drain the base of the tank (on NBs usually by pump or syphon through filler) at least once a year & inspect what you get out. Keep going until what comes out is bright pink/red with no bits or bubbles.

 

3. If it was just water then do the above, if bug then maybe get it polished.

Edited October 22, 2023 by Tony Brooks

[PeterScott]

15 minutes ago, Spudwynk said:

... the engine almost cut out on us but essentially no more power than tick over when on full throttle...

Similar symptoms, turned out to be a broken/intermittent electrical connection to the fuel pump ...

[StephenA]

content removed.

Edited October 22, 2023 by StephenA

[pearley]

If your filler us one of the flush fitting ones then change the sealing ring regularly.

[Tracy D'arth]

I regard fuel polishing as a good money spinner for those who can convince others that it is cost effective.

I have never had fuel polished, after all it is only a filtering process.

If there is water in the tank, it has come from somewhere. Either in a fuel delivery, rain/wash into the fill/vent, seam in the tank gone or a build up of condensation over a long time.

If there is water you may get the bug.

I have never done anything in 50 odd years other than suck out the bottom of the tank regularly. A length of copper pipe in a wet vac does the job.

I have never had the bug, never had fuel problems and never used any additives other than a drop of Morris' fuel supplement when I remembered to put it in.

I have bought fuel from all over, used what has come out of others tanks after it has been allowed to settle. Used up old fuel out of boats I have bought and sold.

Have I just been lucky?

[Sea Dog]

1 hour ago, Spudwynk said:

Have had engine serviced, all OK but recommend getting a fuel polish

Is the above a recommendation or a diagnosis? Only it can't be "all ok" if your fuel will cause it to happen again and neither can having the fuel polished be just a recommendation if it's a necessity. I'd look more carefully into whether you actually have a fuel issue before spending good money on polishing what may potentially be perfectly good fuel.

[ditchcrawler]

4 minutes ago, Sea Dog said:

Is the above a recommendation or a diagnosis? Only it can't be "all ok" if your fuel will cause it to happen again and neither can having the fuel polished be just a recommendation if it's a necessity. I'd look more carefully into whether you actually have a fuel issue before spending good money on polishing what may potentially be perfectly good fuel.

As Sea Dog said was it a diagnosis, Ie. Were the filters full of crap and also was the water separator full of water. Did you get back home on tickover or did the engine pick up again?

[dmr]

2 hours ago, pearley said:

If your filler us one of the flush fitting ones then change the sealing ring regularly.

 

Tempting fate here, but I have not changed that seal in16 years and only ever had water in the fuel once. I do however inspect and clean it every time that we put fuel in, and last time I looked it was just about ready to be replaced.

I don't think there is any need to replace seals, or any other component, if you can see that they are in good condition.

 

[Stilllearning]

13 minutes ago, dmr said:

 

Tempting fate here, but I have not changed that seal in16 years and only ever had water in the fuel once. I do however inspect and clean it every time that we put fuel in, and last time I looked it was just about ready to be replaced.

I don't think there is any need to replace seals, or any other component, if you can see that they are in good condition.

 

Working on the principle of if it ain't broke don't fix it, I agree - but keep a replacement part ready, for when it does.

[robtheplod]

Instead of paying lots for a fuel polish, you can make the bits needed yourself, or there is the low, low budget way:

 

[Spudwynk]

2 hours ago, Sea Dog said:

Is the above a recommendation or a diagnosis? Only it can't be "all ok" if your fuel will cause it to happen again and neither can having the fuel polished be just a recommendation if it's a necessity. I'd look more carefully into whether you actually have a fuel issue before spending good money on polishing what may potentially be perfectly good fuel.

A recommendation. I'm trying to get the marina services to tell me what they found but they are being v slow. 

 

Being leisure boaters it's hard for us to find the time to do jobs ourselves so we ha e to outsource a lot of them

50 minutes ago, dmr said:

 

Tempting fate here, but I have not changed that seal in16 years and only ever had water in the fuel once. I do however inspect and clean it every time that we put fuel in, and last time I looked it was just about ready to be replaced.

I don't think there is any need to replace seals, or any other component, if you can see that they are in good condition.

 

What does a filler cap seal look like? Sorry we're fairly new to ownership so not sure what we're looking for

2 hours ago, ditchcrawler said:

As Sea Dog said was it a diagnosis, Ie. Were the filters full of crap and also was the water separator full of water. Did you get back home on tickover or did the engine pick up again?

Trying to get the marina services to tell me but so far not forthcoming

 

Engine struggled as we were turning on the trent. We limped back at tickover to sawley cut. Sat for 10-15m. As we tried to get back in the marina it was OK for a couple of mins then struggled for a few mins then ok again

 

Webasto central heating also wouldn't fire properly and is fed from diesel tank

 

Not really sure what next best steps are but as leisure boaters hard for us to find time to sort bigger jobs

 

[Iain_S]

What were the filters like on the service?

If you have an electric fuel pump, it may have a filter, which is often forgotten in a service, and, being small, is easily blocked. Similarly, with a mechanical pump, there may be a filter gauze in there which, similarly, is easy to block.

[Tony Brooks]

To sum up abut polishing - not enough detail info to give a definitive answer. It all depends upon what was found in the filters/water traps.

[pearley]

3 hours ago, dmr said:

 

Tempting fate here, but I have not changed that seal in16 years and only ever had water in the fuel once. I do however inspect and clean it every time that we put fuel in, and last time I looked it was just about ready to be replaced.

I don't think there is any need to replace seals, or any other component, if you can see that they are in good condition.

 

 

 

2 hours ago, Stilllearning said:

Working on the principle of if it ain't broke don't fix it, I agree - but keep a replacement part ready, for when it does.

For 7p I'll carry on changing it every fill.

Edited October 22, 2023 by pearley

[dmr]

35 minutes ago, pearley said:

 

 

For 7p I'll carry on changing it every fill.

 

Its also worth changing the cylinder head gasket each time you change the engine oil (😀Only joking)

[ditchcrawler]

3 hours ago, robtheplod said:

Instead of paying lots for a fuel polish, you can make the bits needed yourself, or there is the low, low budget way:

 

I have never been involved in diesel polishing but we use to have the hydraulic oil offshore polished and one of the important points was getting all the crap out of the tank, so the oil was pumped round via filters ad a reasonable speed and fed back into the tank to stir up anything that may be lurking in corners until it was flowing clean 

[Tony Brooks]

No one has mentioned smearing the O ring with something like silicon grease so it slips ad side to make a better seal - a bit like oiling spin on oil filter rubbers.

[blackrose]

57 minutes ago, pearley said:

 

For 7p I'll carry on changing it every fill.

 

I'm actually surprised people are still using those flush screw in filler caps. Never mind about water getting in, they make stealing fuel a breeze for fuel thieves. I replaced mine with a locking filler cap many years ago which also does the other job of keeping rainwater out.

2 minutes ago, Tony Brooks said:

No one has mentioned smearing the O ring with something like silicon grease so it slips ad side to make a better seal - a bit like oiling spin on oil filter rubbers.

 

You've just mentioned it. 

[Bee]

Fuel polishing is just filtering, nothing wrong with that but the real problem is the layer of water at the bottom of the tank compete with rust, bacterial sludge and general muck, that layer of water is seldom sharply defined, it goes through a dull orange colour through to proper diesel over another inch or two and  cleaning it is really difficult.  You really need to pump the best fuel out into a plastic barrel then get an arm into the tank, clean it and put the good fuel back. Its mucky, difficult and needs a removable plate on the tank to get into it. quite honestly a removable stainless steel tank is a better bet than the usual integral tank in the counter. There is much about narrow boats that could be improved. (our boat is not much better but at least I can remove a plate every spring, shine a torch into it and check the whole horrible thing)

[pearley]

12 hours ago, blackrose said:

 

I'm actually surprised people are still using those flush screw in filler caps. Never mind about water getting i

Quite agree with you. It wasn't what I asked for but Lockdown meant things were done which I didn't want but then couldn't change. 

 

What locking cap did you fit?

[Stroudwater1]

13 hours ago, blackrose said:

 

I'm actually surprised people are still using those flush screw in filler caps. Never mind about water getting in, they make stealing fuel a breeze for fuel thieves. I replaced mine with a locking filler cap many years ago which also does the other job of keeping rainwater out.

 

 

Quite a few of these are sited on the Gunnels which means fitting a prominent one presenting a trip hazzard. 

There’s things you can do to the filler pipe arrangement internally that can make theft hard. 
 

Edit are we sure the OP even has a flush fitting screw cap? 

Edited October 23, 2023 by Stroudwater1

[Ex Brummie]

I am always concerned when I read, as stated by the OP earlier, that they have used this  and that diesel treatment. The only time that I have used a diesel treatment, when the vegetable element was introduced, is the only time that I have had fuel problems with gooey deposits in the water trap and filters.

Like others, I annually pump out the bottom of the tank and clean it as best I can.

[Sea Dog]

12 hours ago, Stroudwater1 said:

There’s things you can do to the filler pipe arrangement internally that can make theft hard. 

Also externally: swap the "diesel" and "pump out" labels... 

[ditchcrawler]

Just now, Sea Dog said:

Also externally: swap the "diesel" and "pump out" labels... 

I don't think at my my BSS inspection checked what was under the diesel cap.