free hit
counters
Oil Leak - Engine/Ancilliaries - The Lotus Forums #ForTheOwners Jump to content


Oil Leak


squawk7700

Recommended Posts

Engine on my 2000GT just underwent a rebuild. No water loss anymore which is great but now I'm getting oil leaking from in front of the flywheel. Was pretty significant seepage so I replaced the aftermarket seal with (I think) an OEM seal. 95% solved the problem. At least now it doesn't leak when just sitting there but still after a run I'll get some oil drops, again from in front of the flywheel. Any ideas what might be going on? Thanks for the help.

Link to comment
Share on other sites


Upgrade today to remove Google ads and support TLF.
  • Replies 12
  • Created
  • Last Reply

Top Posters In This Topic

Did you check the where the seal runs on the crank to make sure it did not have a wear groove or somesuch from the previous seal?

All we know is that when they stop making this, we will be properly, properly sad.Jeremy Clarkson on the Esprit.

Opinions are like armpits. Everyone has them, some just stink more than others.

For forum issues, please contact one of us Moderators.

Link to comment
Share on other sites

Unfortunately, if there is a wear groove or scoring on the running surface of the crank that coincides with where the seal runs, you will have less seal lip pressure on the crank and more likelihood of a leak when the oil is warmed up.

Generally, the only real long term solution is to get the crank sealing surface remachined (cylindrically ground probably) and fit a slightly oversized seal. This is an engine apart job. :(

However, having said that, it is possible that the new lip seal was slightly cut on installation. It does not take much of a cut on the lip and you will get a leak.

This would be my first port of call. Try a new seal and take the utmost care when fitting. I am not sure of how the front crank seal is fitted to the V8 engine (or my 4 cyl for that matter) but it may be also be possible if you have scoring to fit rings in the seal housing which reposition the seal on the crank so that the seal does not run on the affected area. This may mean stepping the housing out a bit with shims, but like I said, I am not sure of the setup on the front of the engine.

All we know is that when they stop making this, we will be properly, properly sad.Jeremy Clarkson on the Esprit.

Opinions are like armpits. Everyone has them, some just stink more than others.

For forum issues, please contact one of us Moderators.

Link to comment
Share on other sites

I had a similar problem when I rebuilt the engine on my V8.

Put in an OE seal: annoying drip. Replaced with an after-market: still dripped. Gave up, took the car to Peter Smith. Evidently, s special tool is need to ensure that the seal is evenly spread when fitted. If the tool is not used, the technician told me that it is virtually impossible to get a leak-free fit.

Dry as a bone.

I did consider a slightly undersize ID seal; they are available - but Peter Smith solved the problem.

Link to comment
Share on other sites

1000grid (wet) paper, or even softer ..to 'reshape' the crank surface, in case of slight imperfections. Additionall -place the seal deeper in/more out of original position, other way (or if you have to reuse an older one) -shortem up the spring inside, most springs are not endless, so if you open those and cut on the right end around 1mm off, and fit it again into the lip, the seal will sit notable tighter.

As said, watch out for the "air gap" all around, so that the sealing sits 'centered' to the crank (you can ask for the plastic insertion ring offered on most after market rings in a garage, with a bit of luck they have one that is in equal dimension..)

Other, more practical way: measure the overall inner diameter (without the lip, the dimension of the hard section that is not actually part of the sealing -the ring 'body' if we can say so..) fabricate your own cheap insertion guide tube, out of several layers from paper/hard-paper or a tube of plastic with this dimension ..so that the crankshaft diameter is bigger temperarly and the sealing-ring just fits to the crankshaft end with a little more pressure -with this the ring will sit 'centered' and you can be concentrated now on the position of the sealing-ring cover, the one that also needs to be in an exact position the the rest of the engine/sump, so that there is no step that would cause a leakon the block face/sump face ...

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

Link to comment
Share on other sites

Guest modifiedv8engines

On some American V8 engines where either the front or rear seal leak, we either shift the seal back or forth by a mm or so or alternatively fit a thin wall sleeve over the crank nose and use a oil seal with a larger ID to effect a good oil tight seal.

Find a good bearing stockist and they should be able to find something suitable from one of their catologues.

Good luck

Paul

Link to comment
Share on other sites

the 'modyfied' oil-seals,fabricated with the additional sleeve for the shaft they are running on are actually available on the market -as many car companies have changed the specification for this type (as for the benefit that the 'sealing face' for the sealing lip is changed with the sealing ring everytime, so it doesn't matter if there are slight marks on the crank-shaft foritself..)

thats how those look, I have worked with those versions for years, they work great:

http://de.dichtomatik.com/images/productcatalog/kassettendichtungen/c_1.gif

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

Link to comment
Share on other sites

if even Fiat (IVECO) can use them, think you will still find a set that fits to the dimension of the Lotus crank too ..

worked there 12 years .. nuff said ;)

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

Link to comment
Share on other sites

  • 6 months later...

Thought I'd give an update on the rear seal leak in case anyone has a similar problem. (Keep in mind that I'm no car expert but am slowly learning). As a reminder, my GT had an engine rebuild. Water loss issue solved! But it had a nasty leak from what we suspected was the rear main seal. It would leak just sitting there. Suspected the seal was placed in poorly or torn on insertion. Box out and new seal in and problem 95% solved. But still leaked a few drops after every run. It leaked from the sump side of the flywheel. If you looked up into two "holes"  on the bell housing you could see oil on the nuts.


So back in, box out, and this time we thought we'd removed the crank rear seal oil cover to get a good look at the condition of the crank. There were some wear groves and it certainly didn't feel smooth but I was rather surprised that what I felt could have been responsible for damaging the seal because it seemed so minor. But I guess spinning around it doesn't take much of a deviation from perfectly smooth to affect the rear seal and cause a small oil leak.

We polished up the seal and it felt much smoother. The plan was to then to take 1mm off of the spring in the seal so it would fit a bit tighter as per Gunter's suggestion. But there was still an incredibly small trace of a wear grove. So in the end we decided to put a sleeve onto the crank.

All back together and dry as a bone.  
Thanks for all your suggestions.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



Upgrade today to remove Google ads and support TLF.


×
×
  • Create New...