Oil burning off bringing smoke in through the footwells

[gracep143]

Hello,
I bought my 1972 MGBGT about 2 months ago. Every time the car gets warm and I drive over 50 oil burns onto the engine and gets blown back into the cabin through the foot wells. I can smell and see dusty white smoke. It’s unpleasant to drive with and means I can drive over 50mph. I took it to a garage who said the car is breathing heavy, and would need the head reworking new rings and shells. He suggested a whole new engine or rebuilding mine. £3000. The car drives great though, pulls well, goes quick and hasn’t ever let me down. It would easily go faster than 50 but can’t because of the burning oil.

Do you think I really need a whole new engine if it still drives great? I need a second opinion before spending £3000.
Thanks.
Grace.

[Ian F]

Hi Grace. It's very difficult to diagnose these things without seeing the car, whereabouts are you? Perhaps someone from the forum may be near enough to have a look?

You need to find exactly where the oil smoke is coming from. A worn engine will usually blow smoke out of the exhaust, but you are saying it comes through the footwell?

It could be simply an oil leak under the bonnet which is burning on the hot exhaust.

Try and determine exactly where the smoke is coming from!

Ian F

[Paul Hollingworth]

I agree with Ian, this sounds like an oil leak. Favourite would be rocker box gasket which are about £1 and a piece of cake to fit. Then tappet chest or sump joint which are more difficult but still not major work for a mechanic. Similar for timing chain cover. You also need to look at your breather system. Is the oil separator which is part of the front tappet chest blocked ? Are the hoses in good condition ?
I'd find yourself another garage because £3k for an engine rebuild is twice what I paid. If we knew where you were we might be able to recommend someone to help sort this for you.
Paul

[Charles Farran]

Hi Grace,

When the vehicle is standing are you getting a significant amount of oil dripping to the ground? Like the others i would first check that you haven't got a weeping rocker cover gasket . Secondly i would try & see if the tappet chest covers still have effective seals. (They are difficult to see as well as get at due to the carb heat shield & exhaust manifold). If that side of the engine block is covered in oil then this may be the cause of the problem. (i had a similar issue two years ago with a considerable oil leak from the rear tappet chest). The John Twist Utube video on MGB oil leaks is very helpful & worth viewing before taking any action. When the car is idling , have you tried removing the oil filler cap & placing your hand over the filler neck to see if you get any suction? If not then it may suggest that the engine is struggling to breath & the front tappet chest gauze may be clogged.
As others have said, without seeing the car difficult to help diagnose the problem.

Cheers,Charles

[David Witham]

In addition to what people have said about where the oil smoke might come from you could also look at where it is getting into the footwells.

Over the years people may have removed some of the bungs and grommets that block the holes between the cabin and the engine bay. By closing up such holes you should reduce the fumes getting in and make the cabin quieter. Open the bonnet in daylight and stick your head in the footwell. You may see bright spots of daylight. Also check the gearbox oil dipstick bung and the grommet around the speedo cable which may not show up as daylight.

[Paul Hollingworth]

I think this is the John Twist video Charles is referring to. Don't worry about the PCV valve, you don't have one in your breather system on a 1972 car. If you cant find the leak then the suggestions to test the breather system from John Twist and Charles sound good to me (John calls this the evaporative control system). I would still look at the rocker box gasket first (John calls it the valve cover). From what you describe you must be loosing s significant amount of oil down the exhaust side of the engine. Suspect Rocker box or tappet chest first (John calls this side cover) - Americans eh !

https://www.youtube.com/watch?v=xH_h44FQdXE