Fuel again
I had a near breakdown again today: I have a half tank of diesel and after a fast run down the motorway (75) well its fast for a G... then going up an incline the G started to choke again I pulled over and kept it going by reving and eventually it cleared enough to go on my way.
Does this sound as though it is pulling in air somewhere? I DO Have a few air bubbles in the clear pipe. Is there somewhere the pickup pipe can pick up air when it gets below half full or is this just a coincidence do you think..
I can see a tank removal coming i think!!
I think Whelanrob's advice " At the bottom of your sender is a gauze mesh prefilter,which if clogged would put all joints upstream under a lot of vacuum, possibly drawing air in. " in your last posting points to the problems you are having. It seems to happen when a lot of fuel is required i.e. pulling vehicles out the snow and fast speed so I agree with Bob because your pump is trying to draw max fuel through a choked gause or filter, or some other restriction it's creating a higher vacum in the fuel line and sucking in air. Did you disect that prefilter yet?
tank removal is'nt neccessary to get at this gauze Greeney,it is on the bottom of the fuel level sender,which comes up through the square hatch in the boot floor,after disconnecting pipes and wires.You probably already know this but just thought I would say it.
If you do take out the tank it is a good chance to steam clean the inside and touch up the paint/rust on the outside preventing other problems down the road
bob
HIPPPEEEE. It was exactly as suggested the gauze on the end of the sender unit must have had (NO HYPERBOLE) 1/4" of slimey black sludge over 99% of it. It was a wonder it was still running, only about half a dozen littlegauze holes where showing. When I started the engine again it ran so cleanly no chocking and responsive to even the slightest depression of pedal. I just steamed up "Jubilee Way" and those that know the Dover docks road will know how steep that is. WHAT A DIFFERENCE. I have ordered new filters from medway MB anyway just to make sure. they are being delivered tomorrow.The tank was clean inside.. as much as i could see with a torch. I still aim to remove it in the summer and clean it up but now I CAN wait til the summer.
I have only had this G a year so I would rather do preventative than a repair.
Thanks for all the help.
Greeney absolutely no light at all was shining through mine,and it had gone concave from the suction,was yours still flat?I have'nt had my G on the road since cleaning mine due to other jobs,but I am looking forward to it now seeing as it made such a difference to you
bob
the tank is easy the get out i change mine in the snow last year
the tank and sender is very similar to the 307D i had 7 of these to look after
tanks do gum up over the years so i jet wash them dry and refit good for the next 20 years
Been reading this with interest, just lifted off the square cover to reveal what I guess is the unit, so, if I remove all the pipes/wires and take out the thingy to clean it will all the fuel run back and will I need to bleed it afterwards, going up to Brum tomorrow so a reply tonight would be much appreciated, rog
Yes the gauze was concave. The suction had pulled the sludge to almost a point ON THE INSIDE. I only had a very few holes left to suck diesel through.When i pulled the pipes off it hissed from the vacuum..
I washed it off with white spirit..
Guerdeval...turn the sender plate anticlockwise about 1/4 turn but withdraw slowly as the is only a millimetre around the cylinder and as you get to the bottom where the gauze filter is it will need turning again to get the notches thru the corresponding gaps. VERY EASY THOUGH.
As far as bleeding It has never been so easy. I was having trouble about aug last year bleeding it as the hand pump kept sucking back OBVIOUSLY THE GAUZE blockage even then. it took 5/6 pumps to get air out it squawked like it should and started first time.
Whole thing took 30mins from sart to finish.
Rog, the fuel should not run back as there is no way for air to get in the line. If the fuel does run back then you've got a loose joint in the fuel line ( the old trick with the finger over the drinking straw, remember!!! ) Well done Whelanrob. Greeney you'll be well pleased. Don't go getting any speeding tickets now. :lol:
That will be why it was easy to bleed then :roll:
I have got a few pics if anyone wants to see em! I cant seem to master this image thingy it never works for me... Thats me not the forum)
Clean as a whistle, oh well, better order a bigger turbo, thanks Greeney and Rustbucket I think I did pretty well accomplishing the task anyway, I am not the most accomplished chap with a spanner and it didn't need bleeding, tank is plastic so no dirt in the tank maybe I'm expecting too much of it, by the way Greeney I had to have a new alternator/battery this weekend cos my battery boiled, luckily my wife smelled rotton eggs and I was just a couple of miles from my garage, the alternator was pricey as it needed to have wading capabilities,ironically I even avoid deep puddles let alone go through rivers.
oh well, better order a bigger turbo,
I think I did pretty well accomplishing the task anyway, I am not the most accomplished chap with a spanner and it didn't need bleeding,
Fortunately mines a petrol, but after running diesel vans through the winter for umpteen years, I always add half a gallon of petrol to a full tank of diesel in severe cold - it helps prevent that black sludge Greeney was on about. There are also fuel additives available from your locaql motor factor which absorb moisture in your diesel which is another cause of the problem.
(clocking up another post Rustie!)
John, are you a fermur 'cause the fermur where the wife keeps her horse dose that with his vehicles in the winter. Just thought maybe it was an auld fermin tradition?
an auld van drivers tradition tae pal! OOh we're baeth members ehno. :lol:
I regularly use STP concentrate diesel cleaner at least every 3000miles. but Ive only had the G a year so there is no telling what happened to it in the previous13yrs.
I took delivery of my MB parts yesterday (Great they drop them at my door free of charge) I ordered 2 prefilters and 2 main filters to tide me over for a year or so BUT the prefilters did nt look like what I was expecting, they are white plastic and the inlet pipe comes in at an angle the outlet part goes out the top is this right. I was expecting a see thru paper element type thing. I cant do the image thing otherwise id send you an image.
Thats exactly whats on mine fitted by garage so I think its right, anyway enough of your problems, I'VE JUST MELTED ANOTHER BATTERY!!!!!!!!!!!!!!!, had new alternator/battery fitted weekend as it was overcharging, all OK on my trip up country then 5 miles from home rotton eggs again, got home,lifted lid, battery leaking black goo where top joins bottom, Greeney, what was your outcome?, the good news however after cleaning the filter which wasn't dirty, GOES LIKE A TRAIN!!, 80mph no problem, I think because its shaped like a crisp packet it went flat, I squeezed the sides to make it an open crisp packet and thats all, any ideas on the melting battery folks!!
the good news however after cleaning the filter which wasn't dirty, GOES LIKE A TRAIN!!, 80mph no problem, I think because its shaped like a crisp packet it went flat, I squeezed the sides to make it an open crisp packet and thats all, any ideas on the melting battery folks!!
I expect this should be in the electrical section but anyway.I ca'nt understand why an "expensive alternator" is needed to have" wading capabilities".If you are talking about the alternator with the snorkel that is in some Gs,that is.I swapped my alternator for one out of a Saab 900 '84,got an upgrade to 70 amps(from 55 amps) in the process and could have put the snorkel on if wanted ,but I just could'nt see the point,the front of the alt. is open anyway
bob
Unfortunately I'm a complete mechanical imbecile so I have to believe what the garage tell me, have posted on electrical too with just the electric relevent bit,rog
Chaz I am a criminal psychologist...well Im not a criminal...just specialise in them.
Do you think Guerdeval qualifies for some therapy, he was doing over 80miles an hr in a crisp packet. surely that qualifies as a criminal.........
Ahhh!!! Criminal Psycohologist, just the man we need. What's your analysis of " Oor Rog " Do you think he has been using certain substances which shall remain nameless but may be found in mmmmushroom flavoured crisps ( that's the crisps that come in G Wagen shaped packets :shock: ). Maybe the same effects are created after inhaling toxic battery fumes. I'm worried :shock: Do you think he's loosing it, I mean the trauma of boiling batteries ( what do you expect if you top your battery up with fish and eggs ) :lol: and forking out for umteen alternators must be affecting him. Cleaning clean filters must be a worrying sign :lol: Please give him some professional treatment, if only for his wifes sake, poor woman. :lol: :lol: :lol:
Sorry but with a fishy smell it would of course been prawn cocktail crisps, but why do I need to wear a snorkel?, I've already replaced the door seals so it doesn't leak any longer.
Ask John, He knows all about snorkels. Aint that right Greeney :wink:
Oi! I didn't say a word chazz!
This conversation is becoming far too surreal. More like something from "Alice through the looking glass" than a Vehicle forum...
I think you all need help :lol: From a fuel starved G to prawn cocktail crisps :?
More like something from "Alice through the looking glass" than a Vehicle forum...
I think you all need help :lol: From a fuel starved G to prawn cocktail crisps :?
Soory bout slight temporary change of topic...
Hey Chazz - know owt aboot a 280G from Penicuik, light blue 'E' reg? a' ken someone doon here what bowt it - a respray job and not very good!
PS Whats wrong with Greeney, he's getting a bit cryptic ehno! Alice through the looking glass an a' that. Cannae hondle a bit o' straight talk frae a'body.
No excuse for misinterpretation this time John I added emoticons :lol: I was laughing at the way the conversation developed NOT COMPLAINING :D
Hey Chazz - know owt aboot a 280G from Penicuik, light blue 'E' reg? a' ken someone doon here what bowt it - a respray job and not very good!
Thirty minutes? Thirty minutes?? To locate and clean the filter in the tank? Not on mine its not! The bolt that hold the square lid thing in were rusted but managed to get it off. What I saw then was not a pretty sight: mud,grass, small rocks, after cleaning that all off a very rusty fueltanksender appeared. Good, no not really, all the srews on the hoses and wires have rusted solid and disintergrate when I tried to undo them.
Gave it all a liberal dose of WD40 and will get back to it later. On a positive note though I managed to change both fuelfilters and I think It has made a difference, fingers crossed for tonight.
Oh yes, more good news, I will have to replace both front enginemounts as the engine vibrates badly on them now, oh joy :(
Cheers
Richard
You've got a good one then kashi!
Well, it was dirtcheap to buy :D Oh well, wear and tear I suppose
The good news is that I've managed to get the filter out of the tank, the bad news is that its clean as a whistle, so I've just got a very slow G. :(
Richard
Forgive me if I'm missing the point but:
how come my pre filter in the engine compartment (460) gets blocked up with large particles if there is a gauze filter in the fuel tank ?
As the pre filter is very cheap and disposable why have a difficult to get at filter earlier on in the fuel line ?
I've looked at the sender unit on the top of my fuel tank and I definitely feel it is best left alone even tho' the fuel guage is erratic !
The design is good tho', the tank straps broke a few months ago, but the fuel filler pipe connections stopped it dropping off completely and only the breather pipe came disconnected ! A following motorist recovered the tank guard platefor me from 20 yards back.
robert
Rarrar, if you read my postings you will realise I am a complete tosser where mechanics are concerned but even I managed to clean the tank filter out so it cann't be difficult for a "normal" G owner, if its clogged or flattened the performance difference if apparent straight away,go on, give it a go :P
Robert, the filter is there to avoid any debrise from entering the fuel pipes which could build up and cause major problems, especially at bends etc. So the fuel is filtered at source by a mesh which only holds back relatively large particles ( in Greeneys case, big dods of gunge ) :lol: before it reaches the pre-filter. Take Rogs advice and get the filter checked as it is not a difficult job at all. Clean all the years of grime away with a suitable implement and brush. Compressed air comes in handy if you have it. Get the hose clips off, remove hoses and sender connection, gently tap the metal sender unit housing anti-clockwise with a suitable punch on one of the lugs and the whole assy will pull out for inspection. When I checked mine it was as clean as a whistle but some of the lads have found plenty gunge so that actually answers your original question. While you are at it you can clean the sender connections as this is how I cured my eratic guage readings. :wink:
All points noted, although I'm a believer in leaving things alone if they are working I'll give it a go ! Could definetly do with more performance.
However given the sixe of the particles that fell out of the prefilter I wonder if the gauze filter has not disintegrated !
Robert
I checked my fuel sender today. Mine is a 463 but it is exactly as a 460 until you remove the sender and you can't find the mentioned filter (?). But once in the job, I decided to dismantle the sender because I've had very slow readings lately. I found like 25 cc of black sludge interfearing in the movement of the float so I guess that's it.
I then cleaned all the tiny bolts/nuts that hold the electrical conection to the sender and applied a generous dose of waxoil to the top on the sender, once fitted.
Good for another 13 years, I suppose!
Cheers
The strange thing is that I had only two pipes connected to the fuel sender. One was thicker than the other and exited the sender to the front of the car. I assume that this was the fuel suction pipe?
The other exited the sender to the N/S and it was thinner and was just some 15 cm long and somebody had put a screw to cancel the other end of the hose. Obviously, this was a vent hose cancelled by somebody to prevent ingress of water into the fuel tank when fording rivers, but I am mystified as to the short lenght of the hose(!) I suppose that this is not a problem, given that there are two other big vent hoses to either side of the (plastic) tank.
I would like to hear what you guys think.
Cheers,
Mort, perhaps the extra blanked off pipe is for factory fitted nightheater? :P
Hello all new member calling. I seem to have the same problem remarkably. My G seems to give up under engine strain (hills and the like) I have to rev it like 'billy oh'. It then seems fine for a while.
I intend to change the oil and fule filters but I am interested in this gauze business near the sender unit near the fule tank.
Any idea how I get to it on an June '89 SWB 300GD M2.
Remarkable - First time I log on and I find good stuff
Eamonn
I had all the aforementioned symptoms and was sure I had the same problem.
Sadly my nylon gauze filter at the bottom of the sender was was relatively clean so back to the drawing board.
One thing, I had the tank changed following an accident where the exhaust melted the last one and I discover the garage did not put hose clips on any of the hoses at the sender.
Plus there seem to be a redundant third pipe on the top pf the sender it's been deliberately blocked?
Anyone got any ideas?
I'll change the filters but the clear plastic pre-filter seems worryingly clean.
Hi Eamonn, Could be sucking air into the system. Check all connections on the fuel line are in good order and check all hoses are intact with no cracks etc. There will not nessesarily be any fuel leakage but under serious load conditions you may have a leak in reverse i.e. sucking in air. Sometimes hoses can break down internally and collapse, this usually happens at connections. Have fun :)
The first time my plastic inline fuel filter got bunged up it started drawing air into the system.
This would be the first thing I would change - easy - cheap ( from merc dealer) and not very messy. at least on a 461 engine it is.
Robert
HI ALL
I have just read and chuckled most of the way through this 4 page saga :lol: , sorry but I have seen this so often in Mercedes and other vehicle workshops, mechanics scratching there heads and kicking tyres :x for hours swearing and cursing mr diesel. As there is no surefire cure for all the problems its just educated and logical guessework .
It is worth noting that the fuel stainer in the tank can and does give fuel starvation problems with petrol engines as well as diesel i have seen allsorts around these blighters including leaves & stickers how they get in no one knows + the dreaded gunge if you have this prob use one of the fuel system cleaners after repair and it will help clean the system and lines and injectors i allways add this when doing a major service it really helps and inproves performance, And for the low cost and easy to do job of diesel fuel filters both inline & main i recomend to my customers they are replaced every 12 months do you know the price of an injecton pump.
I hope this all helps Terry
The only way to learn Rog is to get your hands dirty
:D wow interesting way of putting it.
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The filter was binned at the garage I was towed to before AA helped out. So could nt check it. I will check the gauze first I think it does sound right I was confirming really
Thanks RB