Replacing fuel filters?

I just noticed in my Haynes manual that I'm supposed to replace my (petrol) Fiesta fuel filter every 35,000 miles. But I have to admit that the one that's in (under) it has done over 100,000. Has anyone ever dismantled one to find out how dirty they get these days? The pressure seems to build up quickly enough (a second or two) when you turn the ignition on. The filters in my old (70's) motorbike are always clean, but maybe they don't filter so finely?

The missus has a diesel Volvo. Are they fussier about fuel filtering? I think I read somewhere that they are, but (of course) the internet is a mine of information, much of which may not be true :-)

Reply to
Dan S. MacAbre
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I changed one in my last Focus, and cut the old one open. It looked as clean as the day it was made. My current Focus has not had the filter changed in

100k.

I'm retired,and don't drive much, so if it didn't start, or run badly when out, it's not the end of the world. If I was still working, when I relied on my car, I would have changed it.

As cars are made for a world-wide market, it might be that petrol is dirtier in some countries, and hence filter changing would be more important.

I would always replace a diesel filter on schedule, partly due to it being a dirtier fuel and partly because the consequences of a blocked filter can be greater.

Chris

Reply to
Chris Whelan

[snip]

Years ago, my girlfriend had an HB Viva. We stayed at her parents' house one winter (early 1970s). One very cold morning the Viva started, ran for a few seconds, then died. Would not start again, despite cranking for some time.

Investigated: the - mechanical - fuel pump had ice in the bottom, below the filter - result, no flow of fuel. The engine had started on what was in the float chamber in the carburetter. Cleaned the ice out, reassembled - started OK.

So replacing the filter may be a good way to remove foreign material.

Just recently, my petrol lawn mower failed in a similar way - water in the the float chamber.

Condensation in fuel tanks is clearly a problem. Is there a proper solution?

Reply to
Graham J

you can buy a special additive for tanks where condensation is a problem, car shops have it called 'dry-fuel'

My very elderly briggs and stratton grass cutter used to block up with rust off the inside of the tank, my solution is just to fill the tank before storage, then there is very little room for damp air, a tiny bit of oil in there also helps to coat the inside of the tank and makes no difference to the running.

Reply to
MrCheerful

If you are using known brand fuel in a vaguely modern car in the UK then maybe change the filter every 100k, just in case. Diesel fuel filters are usually larger and considerably more expensive, but will do 100k on good fuel. Blocking up will stop the car or reduce its performance, but should not actually hurt the rest of the system.

Reply to
MrCheerful

I put V-Power in it, which is laughable in a 2003 Fiesta; but if I don't, it sometimes pinks/preignites/rattles a bit under load. At least I /think/ it does. I never really got to the bottom of it.

Fortunately, the thing only gets to do a few miles a week now, so the cost of the fuel isn't a huge factor.

Reply to
Dan S. MacAbre

Okay, well thanks for the replies. I'm not going to worry about it :-) Maybe next time I'm planning to get underneath...

Reply to
Dan S. MacAbre

My sisters always use top quality diesel in their cars , both cars are over twenty years old and well over 100k, I changed the fuel filter on one while chasing a cold starting issue, but the problem was actually porous spill pipes the other is still on the original filter, I did check it for any water build up in the filter once via the water drain valve, but there was none. Both still run clean at mot time, there is little coke build up in the manifolds, so I believe that top price fuel is worth the extra.

Reply to
MrCheerful

Haynes haven't yet done a manual (and say they don't plan to) to cover the missus's 2014 V40, so doing anything on it is a bit of an adventure. I've no idea when you're /supposed/ to change anything :-) I think you just have to use a bit of guesswork.

Reply to
Dan S. MacAbre

oil and filter changes, at least once a year. check all fluid levels regularly, inc gearbox/final drive every year. change brake fluid every

3 - 4 years, change antifreeze every ten years. otherwise just inspection and change bits when they need it, such as air filter, pollen filter.
Reply to
MrCheerful

Okay, thanks. Most of that, I'm used to, although I've never (AFAIK) had anything with a pollen filter in :-) I'm also going to have to find out about DPFs, too, I think. Oh, and whatever it is you need to keep an eye on to make sure diesels don't blow up. I've seen one on the roadside, and there are plenty of spectacular videos on youtube. I don't really want the missus to have to find out if you can stop it by putting it into 6th, and then braking heavily :-)

Reply to
Dan S. MacAbre

If you check the fluids regularly and fix as needed, then a self running diesel is very unlikely to occur. They only happen when there is a major problem, such as overfull of oil, usually caused because an injector is leaking inside the engine and adding diesel to the oil. I drained the oil from a Disco once and the oil was largely diesel and several gallons of it. A new head was needed to fix it, even though the drained liquid looked and smelled like pure diesel the big ends etc. were all quiet and it went on for a year or two before being got rid of for other reasons, mainly lack of electrical reliability.

Reply to
MrCheerful

Standard with any system with air-con I believe.

Early systems were prone to choking up. Newer ones seem less so. Definitely not a good idea if your journeys are all short ones though.

I suspect all new ones use injection into the exhaust to regenerate which is preferable to just chucking in more fuel through the regular injectors to regenerate the filter. I believe the latter system can lead to engine oil dilution (with diesel).

Only really a problem on clapped out engines that are ingesting their own lubricant through worn valve-guides, rings etc.

Tim

Reply to
Tim+

Okay, thanks. This is the first diesel we've had, so ATM, it's just another thing to find out about sooner or later.

We tend to run our cars until they almost fall apart, which is why I'm interested :-) I'm assuming diesels aren't all going to be confiscated at some time in the future.

Reply to
Dan S. MacAbre

There will be a "sock" on the fuel pump inlet. Last fuel pump I had out the sock was quite black and needed a good wash in petrol.

Reply to
Peter Hill

Once upon a time I had a hole in the fuel filler neck, which caused dirty water to splash up and enter the fuel tank. It turns out that when you get mud in the petrol you basically can never completely flush it out. Even 20K later it was still collecting in the filter. Since filters are cheap and easy to replace it's not a big deal.

Theo

Reply to
Theo
[...]

It's not that easy to replace on my Focus; it's in a tiny gap up high in front of the fuel tank.

Replacement involves getting the front and rear up, then using a 10mm socket on two extensions to reach the bolt. 1/2" drive sockets are too big, so I use a 1/4" drive one, with all the extensions in the set.

Chris

Reply to
Chris Whelan

That, really, is why I'm asking. The cost of the filter is no problem, but to replace it, I'd have to reverse up my ramps. And I don't even like going up them forwards :-) Actually, I have a winch somewhere, and next time, I'll see if there's a way I can use that.

Reply to
Dan S. MacAbre

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