11 replies to this topic

[Mini-Mouse]

I'm a noob when it comes to the engine so go easy on me!

 

Ever since I've had my Mini it's had an oil leak predominantly from the nearside of the engine, only today did I decide to do something about it. I've been told the leak could be coming from the timing cover so after some difficulty I have removed the radiator, drive belt and fan so I'm in the position shown in image 2. 

 

I've noticed that the oil is also around a join directly beneath the timing cover next to the sump (circled in image 1 - not my photo). What is this part called and does it have a seal I can replace in addition to the timing cover seal to combat this oil leak?

 

(1989 Mini Thirty)

 

Many Thanks 

 

Image 1:

 

http://s1268.photobu...edu3hg.jpg.html

 

http://i1268.photobu...zpsv9edu3hg.jpg

 

<a href="http://s1268.photobu...edu3hg.jpg.html" target="_blank"><img src="http://i1268.photobu...zpsv9edu3hg.jpg" border="0" alt=" photo 6c7b9f35-c67c-4df2-bb6e-d71bfbbc913b_zpsv9edu3hg.jpg"/></a>

 

 

 

 

Image 2:

[Decwhiteoak95]

Looks like the speedo drive housing in the photo

[nicklouse]

ok so you car aint going ant where for a while. that bypass hose does not look good so pull the pump and change the hose while you are at it.

 

to be honest it is a shame you have gone as far as you have as some serious cleaning would have been good to tie the leak down.  tthe speedo drive housing is a rare one to leak. the timing cover crank seal often leaks. which will need the timing cover seal replacing or if you are really unlucky the halfmoon may have deteriorated and failed.

[Mini-Mouse]

ok so you car aint going ant where for a while. that bypass hose does not look good so pull the pump and change the hose while you are at it.

 

to be honest it is a shame you have gone as far as you have as some serious cleaning would have been good to tie the leak down.  tthe speedo drive housing is a rare one to leak. the timing cover crank seal often leaks. which will need the timing cover seal replacing or if you are really unlucky the halfmoon may have deteriorated and failed.

 Why is it a shame? The leak is almost certainly coming from this side of the engine and removing the radiator makes it easier to see and access things, including cleaning. 

 

So I shouldn't bother about the speedo drive housing then? The car has less than 50k miles so it shouldn't be anything too extraordinary. 

 

What's wrong with the bypass hose? Nothing in my engine bay looks good exactly!

Edited by Mini-Mouse, 21 November 2017 - 10:30 PM.

[SolarB]

The bypass hose does look a little worse for wear. It's under pressure and if it splits you loose all the coolant.

 

By the way, nice colour car.

[Carlos W]

I kind of echo Nicks sentiments.

 

A good clean up and degrease so you can see exactly where the oil is coming from would make things a lot easier.

 

But now the radiator is off you're not going to be able to run it. 

 

Having said that, if you change the timing cover gasket (check the condition of the timing chain tensioner whilst you're in there), and then run the car again, if it's leaking from the speedo drive housing you can change that from underneath with the radiator back in place (I think)

[Mini-Mouse]

I kind of echo Nicks sentiments.

 

A good clean up and degrease so you can see exactly where the oil is coming from would make things a lot easier.

 

But now the radiator is off you're not going to be able to run it. 

 

Having said that, if you change the timing cover gasket (check the condition of the timing chain tensioner whilst you're in there), and then run the car again, if it's leaking from the speedo drive housing you can change that from underneath with the radiator back in place (I think)

 

I couldn't really get to places to clean them with the radiator still in there. I deduced by looking from underneath that there is certainly an oil leak coming down the nearside of the engine, so I went ahead and started ripping parts out!

 

I'm 80% sure its the timing cover gasket. I will replace that, clean what I can reach, refit radiator etc then if its still leaking, it's a job to sort for another day! If it does still leak at least I've narrowed it down.

 

If I can remove the speedo housing from underneath then that's great. I don't want to refit the radiator with new coolant, only to have to drain it all and remove it again, to access the speedo drive housing.

Edited by Mini-Mouse, 22 November 2017 - 11:02 AM.

[Ethel]

If you clean it you lose the source of the leak, but if it's still runnable you can make it leak again to pin it down. Admittedly not so easy here.

 

If it was leaking out of the gearbox casing  it'd be by gravity so the leak should still be apparent: save for lower temperature, thinner oil.

 

The way oil is flung everywhere strongly suggests the crank oil seal as it would feed on to the, spinning fanbelt pulley. Looking at the back of the pulley will confirm.

 

When replacing the chain cover, fit the pulley to centre the seal before tightening down the cover bolts.

 

 

 

 

....and the bypass hose is really an emergency replacement variety. I suppose it's survived well enough so far, but now is the ideal opportunity to replace it. Take yer pick. The pump's inlet looks a bit crusty too, aluminium can get very brittle when it corrodes.

[Mini-Mouse]

If you clean it you lose the source of the leak, but if it's still runnable you can make it leak again to pin it down. Admittedly not so easy here.

 

If it was leaking out of the gearbox casing  it'd be by gravity so the leak should still be apparent: save for lower temperature, thinner oil.

 

The way oil is flung everywhere strongly suggests the crank oil seal as it would feed on to the, spinning fanbelt pulley. Looking at the back of the pulley will confirm.

 

When replacing the chain cover, fit the pulley to centre the seal before tightening down the cover bolts.

 

 

 

 

....and the bypass hose is really an emergency replacement variety. I suppose it's survived well enough so far, but now is the ideal opportunity to replace it. Take yer pick. The pump's inlet looks a bit crusty too, aluminium can get very brittle when it corrodes.

 

Most of the moisture you can see is coolant from the radiator removal as I couldn't disconnect the lower hose to drain it, so quite a bit came out of the upper radiator hose connections and went everywhere! Prior to radiator removal, there was no moisture anywhere above the timing cover from what I could see. 

 

If what you say about the gearbox leaking only by gravity is true, then that probably isn't the culprit as I only really get a leak after it has been driven.

 

The plan is to replace bypass hose, timing cover gasket and circular timing cover oil seal.

[Northernpower]

 

The plan is to replace bypass hose, timing cover gasket and circular timing cover oil seal.

 

For what it costs, while its easy to get to, I'd replace the water pump as well . If you become a TMF+ member you'll get another 7.5% discount off the Minispares price and their 3 year guarantee Evo pump http://minispares.co...|Back to search is very good value.

Edited by Northernpower, 22 November 2017 - 01:32 PM.

[Ethel]

At least give it a scrape and see if it exposes shiny metal, if your bits are coming by mail order. It'd be a bummer if it crumbled as you refitted the hose. Water pumps last pretty well, it's only if they're run dry that the bearing usually suffers or lack of anti freeze corrodes the impeller.....and overtight fanbelts.

[Northernpower]

For what it costs I'd still replace the water pump. Looking at it it may well be the original and at 28 years old I think its earned its keep.