MGB Idle + Oil Pressure

Hi All,

I recently bought a 1979 rubber-bumpered MGB GT, with a newly reconditioned engine. This was bought from a reputable MG specialist - and I will check these things with them too - but was wondering what other peoples opinions were.

When I bought the car (a week ago) it seemed to idle fine (at about 800 revs). The oil pressure always seemed slightly lower than my previuos MGB, but generally sat between 50 and 75psi - so I didn't have any need to worry.

A few days after the purchase, it started to struggle when idling, and would quite often just die whilst stopped at lights. When 'struggling' the oil pressure would also drop to about 25-30psi. I also notice that any extra load on the battery (switch lights on etc) would be just one step too far ... and ... chug chug chug splutter ... splutter ... stop.

Thinking the idle speed was just set too I increased this to around 1000 revs (although, I note the haynes manual states 500rpm ... surely that's way too low?). Increasing to 1000 revs solved the stalling, and the oil pressure started to read 50psi idling, and between 50 or 75psi when under load.

Now, a few days later - all seems fine. But I have noticed occasionally when pulling up at lights, the idle speed seems fine - and yet the oil pressure drops down to that 25-30psi region.

I always believed anything

Reply to
Steve Netting
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A couple of things

The idle at 800 is fine and I don't think you will get it much better.

75psi cold and that will drop to 25-30 hot.

What oil are you using you should use oil for old engines - which is a thicker grade and not the synthetic stuff.

I would be chang> Hi All,

Reply to
me

Take it back where you got it and have them check the alternator output.

CR

Steve Nett> Hi All,

Reply to
Charles & Peggy Robinson

Oil pressure at idle on this baby is only at 15 - 25 psi and upwards of 50 psi when running at about 3000 rpm. Tickover is set to approx. 850 rpm at idle with the electric fan running. Would also check the battery condition and the alternator output. My 76 B used to suffer the same until I checked out the above and replaced the battery ( someone had fitted a smaller capacity battery and it could not handle the load). Check balance of carbs at tickover as well. Steve Martin

Reply to
Steve Martin

Thanks all for your help - I have a few things to check over now :)

Thanks again! Where would I be without this newsgroup? lol ...

Steve Bristol, UK

Reply to
Steve Netting

In message , Steve Netting writes

Steve, you'd be stuck by the side of the road like me! ;-))

Reply to
Martin Akehurst

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