Air in fuel system?

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terrance

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can anyone help. I keep losing power in my terrano 11 1999 se. somehow air is building up in fuel system if i let air out of the tap at bottom of fuel filter housing i have full power again untill the air builds back up again ? have taken tolocal garage but they cant figure out how air is getting in all pipes seem to be sound and fuelfilter is ok. Anyone any ideas? :(
 
tap at bottom is for water and crud the one on top at side is air you could have loose union on your fuel lines anywhere between tank an filter a loose filter split fuel line anything like that youll have to check every joint and pi[pe carefully looking for places it may have rubbed on something. how did it start after filter change or for no aparent reason? had an old sirea 2.3d had simlair problem when the fuel filter had been changed one of the rubber o rings that seal top filter stuck to filter housing i didnt realise put new filter on ran rough couldnt work it out then week later picked up bucket with old filter in noticed no o ring checked car hey presto two o rings ran fine with old one took off
 
started for no apparent reason three weeks ago after filling up with fuel .
 
It could be a small hole in the fuel pipe They can rust through above the fuel tank I would start by checking them and replacing them with copper or plastic pipes or it could be a perished rubber pipe.
If the air is building up in the fuel filter it must be a leak before the filter or a problem with the filter or housing another member reported a cheap make of filter that wouldn't seal around the top.
 
question have you replaced the fuel filter lately? if not check that it is tight and not letting air in past the filter seal.
 
Thanks for all the helpfull tips. Took car to a deisel specialist today as after checking all pipes and filter still had air in system. Conclusion was a blockage in one of the supply lines from the tank, if the problem comes back ive been told they will have to remove the fuel tank. fingers crossed the problem is solved!!
 
Isnt there a removable panel in the boot so youy can get the sender unit out.
If there is you can remove it and check the intake and return pipes.
 
Thanks ill take note of that should the air return! Done 60 miles with no problem yet! :smile: hopefull the problem is solved
 
Spoke to soon!! the Air returned today :( Back to the garage! looks like the tank might have to come off.
 
There was a posting recently about removing the tank I think :|
 
terrance said:
can anyone help. I keep losing power in my terrano 11 1999 se. somehow air is building up in fuel system if i let air out of the tap at bottom of fuel filter housing i have full power again untill the air builds back up again ? have taken tolocal garage but they cant figure out how air is getting in all pipes seem to be sound and fuelfilter is ok. Anyone any ideas? :(

What happens when you open the drain tap? do you get any fuel out, or do you hear air hissing? If it is hissing, is the air going in or out?

Air in the fuel filter to that extent suggests that there is very little fuel getting to the filter, I'm wondering though if the lines are blocked and you are getting a fuel starvation problem meaning there is a negative pressure in the fuel filter, you open the drain tap, air goes in, car may run a bit better as the negative pressure has been relieved by air beinf drawn in??


Try & open the drain tap again with a finger over the drain hole, if there is air entering the filetr you might be able to feel some suction on your finger tip as you lift it away.
 
Thanks for the reply. Interesting point... there is only the sound of air (will check direction tomorrow on morning air release :smile: )

Car ran fine for a week after the diesel garage flushed the supply lines. this would suggest to me that there is still a blockage somewhere? going back to garage on tuesday for more investigating!! :?
 
my old transit had this problem there was this kindve mucas floatoting round in tank i carried a 12v tire pump and as all the fuel lines were quick release blew them back into tank it wouldve been better the other way but didnt always happen nr home and big compressor
 
Mucus sounds like diesel bug in the fuel.
Treat with an additive that removes the bug or drain tank and flush out the tank and lines.

You'll be forever replacing the filters due to the gunge clogging them.

We had a crook batch of diesel and took ages to flush out once the fuel was withdrawn off the market.It cost the fuel company big bucks in compo for filters etc..
 
Terrano back at diesel garage today. fuel tank all checked ( thanks for the tip on the panel in the boot terranokid told the garage saved them taking off the tank) all ok in tank so the mystery continues. the mechanics really have no clue whats happening!! have left terrance with them for further investigation! :?
 
collected car today, still no idea whats causing the problem the garage had it for three days and couldn't make it go wrong!!! :roll: ive taken him away for the weekend to see if the problem returns ( i have a feeling it will) :(
 
I would be very careful because the pumps are lubricated using the fuel if you keep getting air in the system there is a good posibility you are going to damage the pump.
 
good point! but what else can i do? there seems to be no fault everything has been checked very carefully! this diesel specialist is suposed to be the best around i dont know what else to do??? :roll:
 
Lets look at this from another angle what exactly are your problems when did they start and what have you done so far.
 
OK
First happened about 4 weeks ago. Filled up with fuel tank was a quarter full when i fillled it. drove about five miles and suddenly couldn't accelerate above 30 - 40 miles an hour ( drove home like this another 40 miles) opened valve at bottom of fuel filter some air came out and then diesel tried car again full power again. continued for three days fine then it happened again. did the same procedure over the next couple of days untill the garage could have a look ( one time the car wouldnt start on first attempt of letting air out ).
First trip to garage. all pipes checked, filter housing, priming pump and new fuel filter put in (even though old one appeared to be fine) fuel lines flushed.
Took car home ran fine for a week. then i lost power again same thing let air out and away we went.
Second gagage visit - fuel tank checked no problem as clean as a whistle i was told. so i left the car with them to drive so they could experience the loss of power problem but they couldnt get it to happen.
so now i have the car again so far been ok but im sure its only a matter of time before it happens again!! :?
 

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