First, I have to thank all of you who have shared your wit and wisdom on this site over the years. It was immensely helpful as I took on my weekend project.

A quick disclaimer -- I am NOT a mechanic. However, I grew up in the home of an uncle who was (he drag raced for several years) and he taught me enough to be comfortable taking pieces off my old VW Beetles and putting them back on. Still, that was years ago and this weekend I took on the biggest mechanical project I think I have ever done.

For reference, I have a 1979 MGB and I've been chasing an oil pressure issue for a while and, this winter, I decided that I would address several potential causes rather than trying to single out THE cause. I had already replaced the oil pressure release valve and spring which helped but still didn't completely fix the problem. In a recap for those who might not have seen prior posts about this -- I have decent pressure when starting but by the time the engine warms up, pressure at idle drops to almost nothing. After pouring over this forum looking for answers, I decided to tackle a bunch of different options. One additional point, I do not have an oil cooler installed.

First on the list was dropping the oil pan which is as much a PITA as most of you have suggested. However, I do have to thank the person who posted a suggestion to remove the cardboard mud shield (which was partially broken away already). That made it possible to put the front bolts back in much easier than it was to get them out. Of course, now I need to replace the mud shield but it needed to be replaced anyway.

While acknowledging that it probably wasn't the cause of my low pressure, I decided that while I had everything open, I might as well replace the oil pump. In looking at the pump I pulled out, it appears to be in pretty good shape and probably could have stayed in place but I already had the new one so now I can take the old one apart and if the internals are in good shape, I'll have a spare.

Then I launched into the biggest part, replacing the rod bearings. I took a wild guess that they had never been replaced before and ordered standard King tri-metal bearings and got lucky that they were the correct size. The hardest part of this process was that the old bearings tended to stick to the crank making them difficult to get loose but that was nothing compared to dropping the oil pan so I can't complain. When I looked at the old bearings, I didn't see any grooves or scoring in them (which is good) but they were worn to the point the copper was showing through so replacing them was probably a great idea.

After re-assembling the lower half of the engine, I pulled the old valve cover which I knew leaked a bit and replaced it with an alloy cover and silicone gasket. I had also planned on replacing the side covers since many of you pointed out that they are often a source of leaks and I had silicone gaskets ready for those too but while I could get the bolt on the front one loose, the exhaust header was in the way and I couldn't pull it out so I tightened it back down and decided to save those two gaskets for another (warmer) day. I poured in new oil (the 20W50 most of you recommend) and other than dumping some all over my new alloy cover, everything was ready to test. Except for one problem.

Last summer, I thought about replacing my battery but after spending a night on the charger, it was perfect all summer. I didn't think about it until I tried to turn the engine over to test the pressure and found out that while my battery had enough juice to keep the clock ticking, it wasn't enough to turn it over. I charged it overnight but, even though the charger said the battery was fully charged, when I tried again, the car just clicked and the door ajar buzzer sounded. When I reconnected the charger, it showed virtually no charge so I think I got an extra season out of a failing battery.

Unfortunately, the weather took a turn last night and while Friday was in the 60's here in Northwest Ohio, today (Sunday) is about 40 with rain and wind so I'll have to wait until next week to get the new battery and test everything out. Hopefully, I'll crank the engine a couple of times and get oil pressure so I can put the plugs back in and start her up to see if I've fixed (or at least improved) the oil pressure. If it doesn't, I'm sure I'll be back here asking all of your expert opinions on what to try next.



Edited 1 time(s). Last edit at 2018-04-15 12:10 PM by MikeVeh.

Too bad about the battery, but you made a lot of progress for one weekend!

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If you didn’t don’t forget to prime the oil pump.

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If you hit your pony over the nose at the outset of your acquaintance, he may not love you, but he will take a deep interest in your movements ever afterwards.



Rudyard Kipling

To be honest, I did but I realized it while I still had the pan off so it was easy to pull the pump, prime it and put it back.

I started Thursday night so I got a jump on the weekend. Plus, my wife was out of town so....

You do not need to remove the pan to prime the pump. Remove the feed pipe that goes from the back of the block to the oil filter. Put a funnel in that hole and pour in some oil. Put the car in fourth gear and push it backwards. That will suck oil into the pump.

Did you do the rod bearings while you were in there too? I think that if your three center mains were on copper I would have done the rods.

I expect you will have better pressure now regardless.

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Michael J. Caputo
'79 RBB and '73 CBB owner with extensive experience in 12v Audio System design and installation.
Vendor of Regalia and Promotional Products. Forum Member with a warped sense of humor.

I only did the rod bearings. I thought about the center mains but decided not to at this time. Not sure why but there must have been some reason....

So here's the update. New battery, same issue. Read a couple more forum posts, check some electrical connections, tighten battery ground. Try again and then -- we have pressure! Replace plugs, reconnect plug wires, a little carb cleaner, turn the ignition, fire it up! Ran a little ragged for a few minutes but then smoothed out. Took my wife for a ride, pressure warm never dropped below 50. All in all, a success. Except....

Popped to hood when I got home and I can tell I have a leak somewhere. Then I noticed some oil in the driveway where I sat while my wife got out of the car.

Here's my non-mechanic dumb question of the day. I put an alloy valve cover on with a silicone gasket. Used RTV to seal the gasket to the cover. Should I have done the same between the gasket and the cylinder head? Would oil leak out between the head and the gasket if I didn't?

It's not a lot of oil but enough to be worrisome so I want to figure it out. Thanks in advance.