bgt oil pressure issues.
Discussion
this is a strange one.when i start the car,oil pressure sits at around the 50 mark then it fluxtuates on the gauge up and down to zero,engine starts clattering then the pressure shoots back up to 50 and engine is quiet again.it does this only for the first couple of minutes at tickover then is stable once warmed up.plenty of oil in it.not sure if it's a broken pick up pipe or what? advice or thoughts welcomed!
hopefully someone who can help more will be along soon, in the meantime . . .
sounds to me more like it could be a choke/carbs/vacuum/timing type issue possibly
consult the owner's/Driver's Handbook for details - this isn’t a workshop it's what you'd have got as a new owner when the car was new, it's full of great information - http://www.mgocshop.co.uk/catalog/Online_Catalogue... other providers are available
regular full and proper servicing and regular driving of the car finds, sorts and helps to prevent most issues
as your BGT isn't on your Profile it might help if you put which year yours is as they did vary over the years
sounds to me more like it could be a choke/carbs/vacuum/timing type issue possibly
consult the owner's/Driver's Handbook for details - this isn’t a workshop it's what you'd have got as a new owner when the car was new, it's full of great information - http://www.mgocshop.co.uk/catalog/Online_Catalogue... other providers are available
regular full and proper servicing and regular driving of the car finds, sorts and helps to prevent most issues
as your BGT isn't on your Profile it might help if you put which year yours is as they did vary over the years
Edited by na on Saturday 24th December 09:54
op, this could be a fuel or electrical problem i.e. when fuel/electrical problem occurs engine partially stops; hence fluctuating oil pressure gauge. suggest over christmas period get engine up to full operational temperature, then check all wiring, fuses, connectors under bonnet, maybe replace fuses with new ones they can throw up some spurious faults with intermittment contacts. then re-start engine. if fault re-occurs check fuel supply, filters, carbs, float chambers, pump et al. also, is your ignition/distributor okay?
if none of the above, then start to think about oil pick-up tubes, oil supply, oil pump spring etc, good luck.
if none of the above, then start to think about oil pick-up tubes, oil supply, oil pump spring etc, good luck.
It could be the oil pick up pipe in the sump has dropped to the bottom due to support brackets breaking and is partially blocked so not allowing good enough flow. Does the pressure drop when you rev it and then rise when it goes back to tickover? We had this once with a B and it's a common problem related to vibration on Jaguar XK engines.
jagracer said:
It could be the oil pick up pipe in the sump has dropped to the bottom due to support brackets breaking and is partially blocked so not allowing good enough flow. Does the pressure drop when you rev it and then rise when it goes back to tickover? We had this once with a B and it's a common problem related to vibration on Jaguar XK engines.
+1thanks for input so far.its a 73 car.with the choke out it sits at around 2k rpm,sounds sweet then pressure momentarily drops to zero for a few seconds,sounds like a bag of nails then resumes normal pressure and all is well.recently replaced condeser in dizzy,set timing and carbs up afterwards etc.think it is oil pressure related by the way it sounds when it drops to zero on the gauge.maybe worn oil pump?cant see how timing would effect the oil pressure if it is sitting at a steady 2k rpm? more input welcomed!
Edited by crispian22 on Friday 23 December 19:59
I'm not over familiar with the B series but as it's like a big A series in most ways this sounds like a problem with the pressure relief valve sticking open and letting pressure drop.
Hearing engine noises whilst the pressure has dropped (IMO) is further evidence of this rather than a faulty gauge, as the noise does quieten (as I understand it) when pressure returns.
I would advise undoing the nut that holds the valve in place and attempting to withdraw the valve and whatever foreign body is jamming the oilway. Clean the valve and the passageway with pipe cleaners or the like. Gun cleaning brushes are said to be ideal for this... I never owned any so I can't say for sure
I would definitely get it looked at rather than keep using it with possible catastrophic results.
Hearing engine noises whilst the pressure has dropped (IMO) is further evidence of this rather than a faulty gauge, as the noise does quieten (as I understand it) when pressure returns.
I would advise undoing the nut that holds the valve in place and attempting to withdraw the valve and whatever foreign body is jamming the oilway. Clean the valve and the passageway with pipe cleaners or the like. Gun cleaning brushes are said to be ideal for this... I never owned any so I can't say for sure
I would definitely get it looked at rather than keep using it with possible catastrophic results.
I thought of pressure release valve but I thought I remembered from a previous thread that these rarely play up but if your careful with removal and note correct order of bits and replace it to correct torque and/or setting then cleaning it can do no harm and if it sorts the problem then it was a quick and easy solution
Why do you need to torque it up? its not required. The sequence of bit's you cannot get wrong,just undo the large cap nut,there is a long spring inside then the actual valve,two bits,thats all.Clean and check the valve for any scoring,it needs to be able to slide in and out easily.On assembly,make sure that before the 'valve' goes back that you have cleaned the hole out and there is NOTHING in there. Lube the valve and slide it back in,get a drift and give the valve a tap or two to make sure its bedded home,then refit the spring and cap. Total cost? Nothing. Good luck hope you get it sorted.
you're right not well put by me, I did put and/or setting but I was rushing then
thinking about if you're going to the trouble of removing it then it'll want inspecting, spring measuring(?), washer(s) replacing perhaps
if there was muck, and the car or engine was fairly recent to me, then I'd also be thinking about an engine oil flush and change of oil and filter too, I'd also clean and thoroughly flush the whole cooling system including the engine block - I do these now when I get the car as you then know for sure it's been done and fully and properly
as usual it'd be interesting to know the outcome of this problem
thinking about if you're going to the trouble of removing it then it'll want inspecting, spring measuring(?), washer(s) replacing perhaps
if there was muck, and the car or engine was fairly recent to me, then I'd also be thinking about an engine oil flush and change of oil and filter too, I'd also clean and thoroughly flush the whole cooling system including the engine block - I do these now when I get the car as you then know for sure it's been done and fully and properly
as usual it'd be interesting to know the outcome of this problem
terenceb said:
Thinking logicically,if there were a problem with the gauge,there would be not clatter when it reads zero.Got to be an oil gallery related thing,or,at worst,perhaps even a shell is moving and blocking off an oil way in the crank,although this would be unlikely.
I would think if a shell was moving he'd have low oil pressure and a bag of nails all the time not just momentarily. If it's started making noises when the pressure dropped then I suspect damage has been done unless once remedied he still has good oil pressure hot and cold. Do you know much about MGBs terence
a gauge is just as it says but the way I read the original post was that there was a noise as it dropped so it doesn't to me suggest the gauge is the problem whether inaccurate or faulty or neither
if the engine was about to stall then the car can give a noise - whether this is the type of noise the OP meant is a different matter and I could have easily misinterpreted this
we’re all trying to help without actually being there and seeing and hearing what is going on so are just making suggestions based on the limited information available to us
I’ll say for myself, as I have in other threads, I’ve very little mechanical ability or knowledge just some ownership experience and most of that I can’t remember
I know perdu has a lot of experience, enough to give qualified advice within the above limitations as opposed to my more speculative suggestions
if the engine was about to stall then the car can give a noise - whether this is the type of noise the OP meant is a different matter and I could have easily misinterpreted this
we’re all trying to help without actually being there and seeing and hearing what is going on so are just making suggestions based on the limited information available to us
I’ll say for myself, as I have in other threads, I’ve very little mechanical ability or knowledge just some ownership experience and most of that I can’t remember
I know perdu has a lot of experience, enough to give qualified advice within the above limitations as opposed to my more speculative suggestions
OP, mine often does the same and is instantly cured by topping up the oil... in fact probably should go and do that myself, thanks for the reminder.
ETA:
If it is the same a mine the noise will be a little-endy/tappety rattle which goes completely as the oil pressures picks back up (after 3 to 5 seconds for my old rat).
I've always assumed it is just the oil level dropping just to the point where the pick-up is snatching at the top surface of the cold oil settled in the sump causing cavitation in the feed and making the gauge burp. To my mind this could even be the opposite of what's suggested above and the pick-up has some how risen as topping up solves it and results in good (40-60psi depending on temp and revs [I know 40 is low but this is the old girl happily idling at ~550rpm!]) running pressure. Mine does it when oil level is just below half way between the marks so it serves as a little top me up request.
Happy New Year!
ETA:
If it is the same a mine the noise will be a little-endy/tappety rattle which goes completely as the oil pressures picks back up (after 3 to 5 seconds for my old rat).
I've always assumed it is just the oil level dropping just to the point where the pick-up is snatching at the top surface of the cold oil settled in the sump causing cavitation in the feed and making the gauge burp. To my mind this could even be the opposite of what's suggested above and the pick-up has some how risen as topping up solves it and results in good (40-60psi depending on temp and revs [I know 40 is low but this is the old girl happily idling at ~550rpm!]) running pressure. Mine does it when oil level is just below half way between the marks so it serves as a little top me up request.
Happy New Year!
Edited by danger mouse on Saturday 31st December 11:49
interesting dm, how much oil are you burning/spilling (are you sure you've got the correct dipstick for your car)
could well be something I've not heard of I can't remember ever having to do much topping up of engine oil with my BGT but I was keen on scheduled oil and filter changes
certainly always worth checking correct oil level and topping up where required without overfill and perhaps checking crankcase breathing and venting
could well be something I've not heard of I can't remember ever having to do much topping up of engine oil with my BGT but I was keen on scheduled oil and filter changes
certainly always worth checking correct oil level and topping up where required without overfill and perhaps checking crankcase breathing and venting
jagracer said:
I would think if a shell was moving he'd have low oil pressure and a bag of nails all the time not just momentarily. If it's started making noises when the pressure dropped then I suspect damage has been done unless once remedied he still has good oil pressure hot and cold.
Do you know much about MGBs terence
Apparently enough to warrant other's copying my idea's.LoL.Are you looking forward to Spa in June?Do you know much about MGBs terence
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