Went for a short drive earlier... when I stopped I heard a bubble, popped the lid and it was coming from expansion tank. It Was a small whistle for a few seconds...
Is it a faulty cap or worse? ?
I Had done 20 miles in the morning prior before this trip... so engine was still warm.
Cheers
Stefan
bubble
Moderators: Doone, westonwarrior
Re: bubble
Heard a bubble before or after shutting the engine off? Whistling an interesting one too.
I occasionally get the 'whiff' of coolant into the cab when stuck in traffic on a hot day, esp. having come to a stop at that traffic followojg5 a relatively high speed motorway dash, I always assume it's gas escaping via the overflow pipe from header tank (from where water poured when the head blew on old engine). Must admit, I wonder how much pressure the cap can maintain with a 'hole' to outside world via that pipe.
But, have never heard it whistling. Would suggest reasonably high pressure gas through a small hole, that pipe or a crack in tank maybe?
Could cap be producing too much pressure? What rating is it showing on the label?
I occasionally get the 'whiff' of coolant into the cab when stuck in traffic on a hot day, esp. having come to a stop at that traffic followojg5 a relatively high speed motorway dash, I always assume it's gas escaping via the overflow pipe from header tank (from where water poured when the head blew on old engine). Must admit, I wonder how much pressure the cap can maintain with a 'hole' to outside world via that pipe.
But, have never heard it whistling. Would suggest reasonably high pressure gas through a small hole, that pipe or a crack in tank maybe?
Could cap be producing too much pressure? What rating is it showing on the label?
Re: bubble
Was upon shutting off the engine... I say a whistle... was more like when letting air escape from a carbonated bottle.. only ever so slightly. Wouldn't have heard it in the cab... I just popped the front open when I stopped at Home. Was for about 5 seconds.
Drove for about 2 hours on Sunday and either way it didn't repeat.
It's got 1.1 written on it. I might just replace the cap, was under the bongo changing the exhaust the other day. Didn't notice any funny business from hoses
Drove for about 2 hours on Sunday and either way it didn't repeat.
It's got 1.1 written on it. I might just replace the cap, was under the bongo changing the exhaust the other day. Didn't notice any funny business from hoses
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Northern Bongolow
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Re: bubble
if you bleed it as per the vids on you tube method you may get some air out.
when you stop the engine you can sometimes get a sloshing kind of sound as the water pump stops and the flow around the system stops, heat in the head can send the hottest coolant to the top of the system.
you should not get any venting out of the system at the cap at all, but as the system cools down you can get a squeaking as the cap allows the system to relax but this is usually only when the outside temps are around freezing.
if its an old cap i would replace it as a first fix as they should really be replaced fairly regularly.
when you stop the engine you can sometimes get a sloshing kind of sound as the water pump stops and the flow around the system stops, heat in the head can send the hottest coolant to the top of the system.
you should not get any venting out of the system at the cap at all, but as the system cools down you can get a squeaking as the cap allows the system to relax but this is usually only when the outside temps are around freezing.
if its an old cap i would replace it as a first fix as they should really be replaced fairly regularly.