Oil leak on 2000SC

#1
We have got a mother and father of an oil leak from the back of our motor. Seems to be coming out of the bell housing drain, so assume rear seal? I recall reading on here somewhere that worn mains can compound the leak as well? Notice in the gasket set, there is a half moon cork or similar seal which I assume goes under the rear main. Suppose this may be leaking as well. We are going to do the bearings shortly anyway, as we have a bit of death rattle on cold start up although the car has only done 70k. Short runs and a lot of stop starts will soon wear the bearings anyway so not supprised. Also have the jingle, so checking the chain tensioners as well. As the SC doesn't have a pressure gauge I'll rig one up before we start to see what we have. Is around 40psi normal for these, or do they run more? Will also check the relief valve if a bit low. Think I'll use Thorntons for the bearings. Any ideas on best place for lower tensioner? Cheers, Rob
 

harveyp6

Well-Known Member
#2
If this is engine oil then it's often the seal on the supply to the cylinder head between the block and head, so clean that area first to either prove it is or isn't that before you start looking at the rear main seal, which rarely leaks on the 4 pot.
 
#3
Cheers for that, will have a look. Is a big leak and certainly is engine oil. We cured the 'red' leak with new gasket. Let you know how we get on.
 
#4
Put the car on the lift and started it up on choke/fast idle. Immediate oil leak from the vents on the side of the auto box bell housing. Engine oil not red gearbox oil. Assume this is coming through the main seal? Probably no other culprit for that much oil leak. Have the sump off now to check bearings and they are all fine, look as good as new. Crank big end journal measures perfectly, can't really get to the mains but the bearings look perfect. Looks like we are in to changing the rear cranl seal unless anyone has any other ideas. Good thing we aren't using it for shows this year. Cheers, Rob
 

harveyp6

Well-Known Member
#5
Is the engine breather system all clear and in good condition? If not it can build up crankcase pressure and blow oil out. The mains can be inspected by removing the caps to see the bottom shell, and sliding the top shell around the crank. It's the bottom half of the mains that take most of the load, and the top half of the big ends.
 
#6
Have inspected the rear and number two main bearings, no problems there at all. Just looked at number 4 big end bearings as the rod happened to be in position, these are fine too. Will have a look at the manual to see where the relevant breathers are and check them. Having taken the rear main cap off the rear seal looks in OK condition, certainly not 'hard' or ripped in any way, at the bottom at least, but seals can leak anyway, even if they look good. Hope I find something in the breather system to save removing the box to do the seal. Will have a look tomorrow. Thanks very much for your input. Rob
 
#7
OK, I give up. Checked all the bearings, the breathers, put the thing back together and guess what? No leak. The only thing I did extra as such was to smear some Hylomar round the main rear seal seat on the main bearing cap. Can't see that having any effect? Not that I'm complaining. We still have the rattle on idle from what we assume is the timing chain tensioners, which looked fine when the sump was off. Going to check the oil pressure if we can find out what thread the switch is (see other post) as it seems, according to a post somewhere, the tensioners are oil dependent. Other than that have no idea what has happened to stop the massive leak that we had. I mean huge, like an aerosol cap full in just about a couple of mins. Funny things these old cars. Cheers, Rob
 

Demetris

Well-Known Member
#8
I recall many cases of single carb cars having a rattle from a spacer or something within the inlet manifold. It will be apparent as soon as you remove the carb. Make sure that it's not something simple like this before investigating more serious stuff like timing chains.
 
#10
Interesting. going to remove the carb. shortly anyway to overhaul it, so will check nothing is falling off. Noise seems more to the front of the motor. Removed the fan belt and still there, so it's not alternator or water pump. Update on the oil leak, it's back, but not as bad. Going to give the car a thirty mile run tomorrow and see what falls off. Interestingly, when we drained the oil to remove the sump, we only got 3-1/2 ltrs out, so a full ltr short in no use at all, around 25 miles. That was the size of the leak we had! Thankfully it is now only a slight leak not the torrent we had before. Cheers, Rob
 
#11
Got the leak sorted. Rear oil seal trashed. New fitted, job sorted. Managed to find two new Renold tensioners for an MGB engine. Same thing as the Rover, but with no retraction bung. Oddly the tensioners had the same part number on as the old Rover ones. Perhaps they modified the standard Renold item for their engine by putting the bung in the end? Got them both in fine with no problems, so now we have no jingle on the chains and no oil leak. Bliss.
 
#12
If this is engine oil then it's often the seal on the supply to the cylinder head between the block and head, so clean that area first to either prove it is or isn't that before you start looking at the rear main seal, which rarely leaks on the 4 pot.
Funnily enough I've just bought a 65 2000sc with a very small amount of oil coming out between the block and the cylinder head, (when i wipe the oil away more seeps out), It got really bad just after I topped the oil up but sort of stopped. Does this mean a new head gasket or should I retorque the head?
Thanks
 
#15
Mate of mine had the same problem. Was the 'o' ring as Harvey says. Not a bad job really. Might as well seat the valves at the same time. Good job we did Johns, as we found two broken valve springs!
 
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