Forum:
My Fourtrak has just started making a very loud groaning noise from under the bonnet when it have gone down a long hill on over-run. I.e with no accelerator. After a reasonably long decent like this the noise lasts for about 3 seconds then goes. The next down hill may not cause the noise but the one after will. It is almost like pressure is being relieved then progressively builds up again
I have also noticed their is pressure in the fuel tank which is released when opening fuel cap but I have cleaned fuel filler cap and checked fuel filler diaphragm is working properly and anyway this effect was there before the latest noise described above.
I am mystified, could it be something to do with fuel return to the tank when it is not being used by engine on over run? I have looked at the forum and can't find similar problem.
Apart from this the engine starts, ticks over and runs perfectly.
Be grateful for any ideas. Thanks
Look at the tank and you will
Look at the tank and you will see either one, two, or three small pipes exiting it, depending on model, year, and configuration.
Trace these pipes up the vehicle body and you will see a small plastic tube the size of a small fuel filter attached to one of them, this is the breather which either become clogged with mud or just corrode internally.
Inside the breather is a ball bearing held in a central position by a spring either side, this allows air out as the fuel expands due to heat, or air in as fuel is used and a vacuum is created. Fill this with WD40 or similar once removed and see if it will free off by blowing it from each end and air passes.
If it won't free then replace it with a cheap fuel filter of the disposable type and replace annually.
Fuel noise on over run
Many thanks for taking the time to reply and what you suggest sounds like the answer but as yet I have not found the device you mention. However I cannot get the Fourtrak up onto a lift until next week. I must admit the noise seems to come from under the bonnet though. Thanks again for your help
Fuel noise on over run
PS the model is a Diahatsu Fourtrak Independent 2.8 TDS Model F73 of 1997. I don't know if this model is fitted with the device you describe? Thanks
Fuel noise on over run
Thanks for your replies. Have now traced the noise to the fuel filter, so next stage is to replace this but can't understand why this unit would make a noise on over run. Anybody have any ideas so I could prevent it happening again. Could it be caused by poor quality fuel or blockage, but then why only on over run? I think it will probably remain a mystery.Thanks
nooooo lift
easy to find above, off side rear panel internal above wheel arch pull it away...hey presto.
Full of ideas but no time to do them!!
www.bloodredoffroad.com
www.milneroffroad.com
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