oily alternator

[mct340]

Has anyone figured out how to stop oil from misting out along the dipstick and slowly knocking out the alternator? The sparkplug boot idea doesn't do it.

[rgh0]

Have a close look at your front cover especially around the two top bolts, they have a tendency to crack there and leak oil onto the alternator. it may not be coming out the dip stick

cheers
Rohan

[1964 S1]

I'd also check for excessive blow by.
I've never had the problem you describe in thirty plus years of Elan ownership and I do have oil leaks.
I would clean up the engine bay 'til it's spit shine and then see if the oil is really coming from the dipstick. If yes, I go back to the blow by problem, breathing congestion, too many Gold Leafs.

[1964 S1]

I just had an ah ha moment.
I think in the archives you may find some stuff about the exposed length of the dip stick tube. It's a slip fit, and if not properly adjusted, oil can find it's way out... how far is it from the top of your tube to the block?

[mct340]

Thanks for the ideas... got me thinking.
I think I'll try taking the dipstick out and capping off the tube to see what I get. The dipstick can ride in the trunk for a while.
Mike

[tcsoar]

Hi,

It could be positive crankcase pressure,(as mentioned above by 1964 S1)
possibly caused by amoungst other things, either blocked breather or worn rings. I did have a similar experience many years ago that was caused by the latter.

Chris.

[tdafforn]

Also had the same problem, high crankcase pressure with worn rings etc..
Ended up capping the dipstick tube
Tim

[Foxie]

The breather does not have to be blocked, or the rings excessively worn to get some oil mist being blown out the dipstick tube, and as you say, eventually causing alternator problems.

I eventually solved this problem by glueing a larger diameter BMW dipstick tube over the original stump, and cutting the matching BMW dipstick to appropriate length.

The BMW dipstick has a very effective neck seal which keeps the alternator area oil-free.

Non-original, but effective.

[gordonlund]

3 points
1 Breather tube to carb backplate blocked
2 Breather tube head to cylinder block restricted
3 Using excessive engine rpm

Any one of these will cause oil leaks, the easiest path being the dipstick as no seal as OE (original equipment).

Engine wear is obvious, the likely contenders being valve guide wear (they end up oval!!) causing +ve pressure in the cam boxes, exhaust side being worse case as no direct breather as at the inlet box.

Piston and rings and cylinder bore are obvious but excessive wear will result in high oil consumption, ie less than 500 miles to the pint.

Sealing the dip stick is a good cosmetic mod if you just want to keep mild mist at bay, but sealing against excessive blow by will only result in creating worse leaks elsewhere.

Gordon

[CBUEB1771]

Sealing the dip stick is a good cosmetic mod if you just want to keep mild mist at bay, but sealing against excessive blow by will only result in creating worse leaks elsewhere.

Of course this is technical true, but unless the crankcase breather on the inlet side is blocked you would have a hard time measuring the effect of sealing the dipstick tube.

[gordonlund]

Russ,

You are right and the main problem could be as I have seen many times on Twin cams is the rubber breather tube twixt head and block which swells in all directions due to oil and heat effects. This causes the bore to restrict and eventually block with sludge.

Some specialists marketed an aluminium tube to replace the rubber item which would theoretically remove this problem. I always thought that they could be susceptable to oil leaks if not sealed properly. Has anyone had any experience of using these?

Gordon

[rgh0]

I use a 1 piece aluminium tube made by the Elan Factory in my engines these days. It is a press fit into the block with a little loctite to ensure a seal and seals with an O-ring at the head, I also put a small smear of silicone behind the O ring as a back up seal. Once in place I have never had any problems with them.

You need to check the bore on the hole in head is clean so the o-ring seals properly and check the diameter of the hole in the block before ordering the part as the Ford blocks varied a little in this area.

cheers
Rohan

[1964 S1]

Can the tube be installed in situ?

[SADLOTUS]

No.





Off with his head!

[FOX5D]

So how can you know for sure that you have +ve pressure? My engine (S4 SE) has been professionally rebuilt including new piston rings and the head and valve gear made like new by Vulcan Engineering. The oil breather pipe from the head to the airbox is clear and the engine rebuild was only done 2k ago by Phil Webb at the South West Lotus Centre.

I have oil leaking over my new alternator and I am pretty sure that it is coming from the dipstick tube (I have tried different things to shroud the dipstick and on a couple of occasions it has stopped the leak-but it keeps coming back) I will make absolutely certain of this tomorrow by sealing the tube.

Assuming for the moment that the oil is coming from the tube, how do you know the reason why? Excessive wear in the tube/dipstick? or +ve pressure? My S3 with a big valve motor doesn't leak oil from the dipstick tube! A friend of mine had an S4 and fitted an oil breather to the cam cover and he said it stopped his leaks. But I don't want to do this unless I am sure that there is +ve pressure.

Fed up with oil leaks

Jim