MG Midget Oil Pressure
Discussion
Hi everyone,
I've recently bought my first classic, a '67 midget. It's a fantastic little car and a pleasure to drive.
I'be been reading through the workshop manual which states the normal oil pressure on starup should be between 30 and 60psi. I have 50psi quickly (after a minute or so) reducing to 30-40 psi.
The workshop manual also states that the oil pressure at idle should be between 10psi (min.) and 25psi. I have 20psi at idle once the engine is warmed up.
During normal driving the oil pressure is between 35 & 40psi @ 3k - 3.5 RPM.
The reason for me querying the oil pressure is after doing abit of reading online (always dangerous I know) the consensus seems to be 60psi on startup and min 40psi when warm?
Could you please tell me if this is correct and if so do my oil pressures seem abit low?
The cars idles fine and there doesn't seem to be any unusual or concerning noises from the engine during idle or normal driving.
I also haven't noticed any smoke from the exhaust during idle or acceleration.
Any feedback or pointers would be appreciated for this newbie
Thanks in advance
I've recently bought my first classic, a '67 midget. It's a fantastic little car and a pleasure to drive.
I'be been reading through the workshop manual which states the normal oil pressure on starup should be between 30 and 60psi. I have 50psi quickly (after a minute or so) reducing to 30-40 psi.
The workshop manual also states that the oil pressure at idle should be between 10psi (min.) and 25psi. I have 20psi at idle once the engine is warmed up.
During normal driving the oil pressure is between 35 & 40psi @ 3k - 3.5 RPM.
The reason for me querying the oil pressure is after doing abit of reading online (always dangerous I know) the consensus seems to be 60psi on startup and min 40psi when warm?
Could you please tell me if this is correct and if so do my oil pressures seem abit low?
The cars idles fine and there doesn't seem to be any unusual or concerning noises from the engine during idle or normal driving.
I also haven't noticed any smoke from the exhaust during idle or acceleration.
Any feedback or pointers would be appreciated for this newbie
Thanks in advance
Welcome to a whole new world of fun (and occasional financial pain accompanied by skinned knuckles)
Doesn't sound bad, it could be as simple as the previous owner using an oil at the thin end of the recommended range. Swapping from 10w40 to 20w-50 probably adds 10psi. But then if the pressure is too high the oil isn't flowing as fast and as a result gets hotter and breaks down quicker. Low oil pressure is a proxy for bearing wear, but if it's not making horrible noises, it's probably fine. Mine's done 20,000 ish miles since a rebuild and is still at the high end, friends had new engines with barely average pressure so it's not something to worry about in isolation.
Worth going along to your MGOC local branch's meeting, it's usually at a pub or curry house, mostly just for reassurance that whatever strange noise it's making this week is normal and "they all do that". The good news is, even if something does fall apart, it's cheap to fix, I'm part way through rebuilding my entire suspension with new everything (apart from wishbones), costing barely more than a set of tyres on my other car! And seemingly only taking 2 spanners to do everything!
If you've not already, it might be worth servicing it just for your own peace of mind, the parts are cheap it's worth doing regularly. Halfords have 20W50 classic oil on sale at £15.99 at the moment, filters are <£5, you can probably get similar stuff even cheaper if you shop around.
If it's your first classic car then learn how to replace adjust the points (and carry a spare set) otherwise they will let you down at the least convenient time for the sake of knowing how to change a 99p part! Not that that was a lesson learnt through bitter experience waiting for a recovery truck in the rain only to see him fix it in 30seconds flat or anything!
If you've not got it then get a copy of the drivers handbook off ebay, it'll list all the service items and frequency, worth doing the full monty just so you know it's done. Also shows all the grease points, how to check gearbox and differential oil levels etc. There's also a workshop manual if you google it, it's not quite as thorough as the haynes manual, but it's got exploded diagrams for most fixable parts and it's free so stupid not to have a copy printed out.
Doesn't sound bad, it could be as simple as the previous owner using an oil at the thin end of the recommended range. Swapping from 10w40 to 20w-50 probably adds 10psi. But then if the pressure is too high the oil isn't flowing as fast and as a result gets hotter and breaks down quicker. Low oil pressure is a proxy for bearing wear, but if it's not making horrible noises, it's probably fine. Mine's done 20,000 ish miles since a rebuild and is still at the high end, friends had new engines with barely average pressure so it's not something to worry about in isolation.
Worth going along to your MGOC local branch's meeting, it's usually at a pub or curry house, mostly just for reassurance that whatever strange noise it's making this week is normal and "they all do that". The good news is, even if something does fall apart, it's cheap to fix, I'm part way through rebuilding my entire suspension with new everything (apart from wishbones), costing barely more than a set of tyres on my other car! And seemingly only taking 2 spanners to do everything!
If you've not already, it might be worth servicing it just for your own peace of mind, the parts are cheap it's worth doing regularly. Halfords have 20W50 classic oil on sale at £15.99 at the moment, filters are <£5, you can probably get similar stuff even cheaper if you shop around.
If it's your first classic car then learn how to replace adjust the points (and carry a spare set) otherwise they will let you down at the least convenient time for the sake of knowing how to change a 99p part! Not that that was a lesson learnt through bitter experience waiting for a recovery truck in the rain only to see him fix it in 30seconds flat or anything!
If you've not got it then get a copy of the drivers handbook off ebay, it'll list all the service items and frequency, worth doing the full monty just so you know it's done. Also shows all the grease points, how to check gearbox and differential oil levels etc. There's also a workshop manual if you google it, it's not quite as thorough as the haynes manual, but it's got exploded diagrams for most fixable parts and it's free so stupid not to have a copy printed out.
Edited by thisisnotaspoon on Thursday 26th March 23:11
Sounds okay to me. 
Bare in mind unless you're oil pressure gauge is calibrated it might not be 100% accurate. What you ought to do is watch for inconsistant behaviour, you want the pressure coming up as soon as the car is started.
Manufacturers have either stopped fitting gauges. Or like modern temp gauges they are damped so unless the car is getting very hot they don't move from the middle.
This stops the driver worrying.
As has been said give the car a service, it'll help you to "bond" with it.
Bare in mind unless you're oil pressure gauge is calibrated it might not be 100% accurate. What you ought to do is watch for inconsistant behaviour, you want the pressure coming up as soon as the car is started.
Manufacturers have either stopped fitting gauges. Or like modern temp gauges they are damped so unless the car is getting very hot they don't move from the middle.
This stops the driver worrying.
As has been said give the car a service, it'll help you to "bond" with it.
Thanks for the feedback guys, really appreciated.
I haven't yet done an oil change but I'll do this, the oil filter and spark plugs over the weekend.
Fortunately she came with a copy of the Haynes manual which has proven invaluable! The only item I don't have is the owners manual, I'll have a look on EBay.
Again thanks for the feedback, it's put my mind at rest.
I haven't yet done an oil change but I'll do this, the oil filter and spark plugs over the weekend.
Fortunately she came with a copy of the Haynes manual which has proven invaluable! The only item I don't have is the owners manual, I'll have a look on EBay.
Again thanks for the feedback, it's put my mind at rest.
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