Clicking/knocking noise

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Willienelson
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Clicking/knocking noise

Postby Willienelson » Fri Oct 25, 2019 9:26 am

Morning all

Bit of a strange one this, I’ve got a clicking noise that starts as soon as you turn the key, (intermittently), and doesn’t stop when the engine is running.

From inside the car it sounds like it’s coming from the engine bay behind the bulkhead, with the bonnet up it sounds like it’s coming from inside the car behind the bulkhead near passenger footwell.

Any ideas most welcome!

Pete

Sleeper
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Re: Clicking/knocking noise

Postby Sleeper » Fri Oct 25, 2019 9:48 am

Petrol pump ?

John :wink:

MikeNash
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Re: Clicking/knocking noise

Postby MikeNash » Fri Oct 25, 2019 10:18 am

You'll worry if it stops!
Morris Minor, the car of the future. One day they will all look like this!

SteveClem
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Re: Clicking/knocking noise

Postby SteveClem » Fri Oct 25, 2019 12:57 pm

Yes, but you can usually get it going again with a tap from a toffee hammer :D

pgp001
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Re: Clicking/knocking noise

Postby pgp001 » Fri Oct 25, 2019 12:58 pm

If it is the fuel pump it will probably click a few times as soon as you turn the ignition on, this is just replenishing the float bowl with fuel, it will likely do this if the car has not been run for a while.
Once the engine is running it should tick on a steady regular basis to keep up with the demand for fuel.

If it starts ticking erratically while driving it could be an indication of a problem somewhere, maybe a leak, blockage or fuel vapourisation etc.

You will get used to that re-assuring regular tick as you drive along.

Phil

Willienelson
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Re: Clicking/knocking noise

Postby Willienelson » Sat Oct 26, 2019 1:27 pm

Should the petrol pump really be that loud?

You might be onto something though, quick trip out and had to return to the safety of the garage as we couldn’t do more than 10-15 mph, coughing and spluttering as if short on fuel.

Looks like fuel pump on way out, is there an upgrade to the fuel pump or should I just get an original from bull motif?

Pete

paul 300358
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Re: Clicking/knocking noise

Postby paul 300358 » Sat Oct 26, 2019 1:38 pm

You can check the pump by removing the fuel pipe from the carburettor, place the pipe end in a bottle and get someone to turn the ignition on.

Sleeper
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Re: Clicking/knocking noise

Postby Sleeper » Sat Oct 26, 2019 2:23 pm

I think they do go louder with less fuel in them , when did you last fill up ?
Failing that,test the flow as above...

John :wink:

ianmack
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Re: Clicking/knocking noise

Postby ianmack » Sat Oct 26, 2019 4:07 pm

If the pump works furiously without delivering any fuel there may be a leak between the tank and pump so the pump draws air instead of petrol. Check all the other possibilities before buying a pump.

mogbob
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Re: Clicking/knocking noise

Postby mogbob » Sat Oct 26, 2019 4:29 pm

Pete ,
Do the test first and see what the result is.
Can we assume that the car is 1098cc Negative earth ? Is it an original pump on the vehicle or has it been replaced at some time in it's life ?
If original then unleaded petrol " may have done for it ". A new pump will have a diaphragm and washers filter that are compatible with today's unleaded fuel. Check out other suppliers for the price of a new pump. I'd say
that Bull Motif's FUL117 @ £107.40 ( inc Vat ) looks competitive.
If you're handy with the spanners then refurbishing the pump ( up to current spec ) is an option. Burlen…
www.burlen.co.uk is the main supplier for all SU products. You will need their kit EPK 700 £44.56 inc
VAT , plus postage of course. As a first timer with spannering skills you should cope with it in a day. There are Technical pages on the Burlen website to show you how it comes apart and how to put it back together again.
Because the Pump sits " high " in the engine bay , i.e. above the height of the fuel tank , you won't have to worry about draining the tank *** to change the pump.
***
A few provisos.ALWAYS disconnect the battery first. Keep away from any other source of ignition when working
on fuel related items. Working outside is preferable or at least a well ventilated garage.Change the rubber fuel pipe ( for one that is suitable for unleaded ) if the rubber is looking perished / past it's sell by date. Bits can break off , clogging the carburettor , causing the symptoms you describe. The rubber pipe ( sometimes metal braided ) runs from the " Outlet " port of the pump to the Carburettor. The float bowl of the carburetor is clean we assume.
A warning ... changing / refurbishing the pump may not fix the problem entirely. If you're really unlucky it may
be flakes of rust in the petrol tank that are occasionally blocking the outlet pipe. They can sometimes be dislodged by bouncing the rear of the car but this is not a long term fix. Come back to us if you find this problem so we can offer solutions. I've got my fingers crossed for you.
Welcome to the Forum by the way , keep the questions coming we love a challenge.
Bob

Willienelson
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Re: Clicking/knocking noise

Postby Willienelson » Sat Oct 26, 2019 10:29 pm

Wow, that’s brilliant!
Thank you everyone.

I haven’t had time to look further into this as I’m working everyday at the moment, but I can answer some of the questions.

Fuelled up less than 80 miles ago and gauge is working showing more than 3/4’s full.
Yes it’s negative earth and a lot of money was spent on the engine somewhere in 2013/14 with unleaded conversion, but I can’t find a reference to whether the pump was replaced so I’m assuming not.

I believe it’s the original pump having only done 68k, it certainly looks original and I’ve got receipts going back a long way and none of them refer to fuel pump.

When I can get into the garage for an hour I’ll try the test mentioned above, but the fuel filter looks way past it’s best. I’ve a new one to fit so will check pump at same time.

If it is the pump, I think I’ll have a go at rebuilding the old one, I’m not too bad with spanner’s and it’ll be a good lesson for my son too!

Dare I say it?

How hard can it be!!

Pete

mogbob
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Re: Clicking/knocking noise

Postby mogbob » Sun Oct 27, 2019 8:31 am

Pete
Replace the fuel filter first , if it's clogged up. It will certainly be strangling the supply of fuel to the carb and therefore be making the pump work harder. And it's cheaper than a new pump ! Give that a go.
Opinions vary on the after market fuel filter application. My take is that it is superfluous. Everyone has their own
opinion .

There is a filter in the fuel pump and dirt / sediment will collect in the fuel bowl of the carburetor. The SU carb
design has worked well for many decades. A large bit of dirt might stick the float needle shut but it's easy enough to fix. General fine dirt / muck falls to the bottom of the bowl and doesn't affect performance. A clean out every now and again ( several thousand miles ) will improve reliability. Have a spare float chamber gasket to hand ( AUC8459A ) , in case you damage it whilst removing.
If you're tempted to clean out the pump filter , again have a new washer to hand before starting. The plastic filter cylinder can be cleaned with petrol or Meths. Don't attack it with an old tooth brush / or wire brush , only a soft bristle brush. It cannot be described as a robust part and given it's potential age ,might well end up in bits before you know it. Delicate treatment is the order of the day. You'll find a full parts diagram on the Burlen website of both carburetor and fuel pump that I mentioned earlier.
Bob

Willienelson
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Re: Clicking/knocking noise

Postby Willienelson » Sun Oct 27, 2019 9:40 am

Thanks Bob

I’m not a fan of the aftermarket fuel filter either, we generally had late 60’s/early 70’s ford motors on our boats and plastic fuel filters would fail a safety certificate straight away.

They were handy as a ‘window’ into the quality of the fuel in the tank though, and these tanks suffered being around the water for so long.

Pete

Willienelson
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Re: Clicking/knocking noise

Postby Willienelson » Mon Oct 28, 2019 1:34 pm

We replaced the fuel filter yesterday and the innards were rusty and completely overdue for replacement.

Now getting a regular tick from the fuel pump rather than intermittent but the fuel only seems to dribble into the filter.
Should the pump give a good amount of fuel after each click?
And if the pump is on its way out would the clicking get noisier?

I’ve ordered a rebuild kit anyway so I’ll be rebuilding the original in the next couple of weeks.

Pete

paul 300358
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Re: Clicking/knocking noise

Postby paul 300358 » Mon Oct 28, 2019 1:44 pm

Have you cleaned the filter in the pump? the filter is underneath, you just unscrew the hexagonal nut. I would expect it to pump at least a pint in a couple of minutes? Also, I seem to remember someone on here having trouble with the filter inside the tank.

Willienelson
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Re: Clicking/knocking noise

Postby Willienelson » Tue Oct 29, 2019 6:41 am

Thanks Paul, I’ll check that out before I go much further.

Pete


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