Hello

I run synthetic in all our cars; but I haven't in my Disco II with 150K miles because it currently leaks oil, and I've heard that synthetic will make it leak more. (From what I understand, synthetics do not cause leaks, but can aggravate existing leaks).

I'm a pretty firm believer in going synthetic (I swear the engine runs smoother with them), but not anxious to cause greater leaks. What's your thoughts? Anyone make the switch at this kind of mileage? I'm wanting to do this, since the car lives in the snow country with sub zero temps...

Thanks.

 

You'll here otherwise but I learned in shop changing oil that late in the game is not a good thing. But consider this. If you flush your engine with ATF before you make the swap, the atf will (in a small way) will expandand renewyour gaskets and even slow leakage. I learned in tech college that ATF helps slow leakages by renewing existing rubber or similar gaskets. Plus it will clean your engine and prepare it for the synthetic. If you really want to do it, just be sure you flush itfirst, especially at that mileage.

 

Synthetics will be ok. They will clean out your engine and re-new your seal, as ATF flushing will, only over a longer period of time. Wouldn't hurt to flush, but I don't think its required. Your leaks may get worse before they get better, but if you flush, be ready to drop the pan and clean out your oil pickup tube. At that mileage, you will have build up and all of that will go straight to the pan.

Your engine does run smoother. Try it in your T-case and diffs. Not sure what year you have, but it may have come with synthetic in it.

 

Synthetic won't cause leaks, but it will most likely make current leaks worse at your mileage. If syn made cars leak people wouldn't reco it as much as they do.

I would recommend either doing some work on the engine like new gaskets before you change to syn, or just stay with normal dino oil and go with a really good brand.

Chris

 

I will just put this out there.....my truck leaked when I got it. I developed a good leak a few months ago, but it was the oil pressure switch. I needlessly changed a valve cover gasket.

It does not leak today. It did not get worse at all.

I would like for all who comment to put what oil they are running and when they first put it in.

I threw Royal Purple in everything (even purple ice in the radiator)at 124300....I am at about 145K now. Runs great (except for the fan clutch holding)

 

If synthetic oil does cause an existing leak to get worse it is caused from the things, synthetic oil will clean out an engine, sludge and lacquer and leave an already leaking gasket to possibly leak more. Also synthetic oil is a much small molecular structure the dino juice and can leak out of very small cracked gaskets.
All things weighed I would still go to the synthetic oil and just keep an eye on the engine for the next month or so for new seaps.

 

Thanks for all the input!

I'm thinking about going with Mobil1 high milage formula, which supposedly does the following per Mobile1:
[*] Extra anti-wear additive helps protect critical engine parts.[*] Reduces the sludge and deposits that conventional oils can leave behind.[*] Contains a special seal conditioner to help recondition seals and prevent leaks.[*] Higher viscosity formula helps reduce oil burn-off and leakage. [/ul]They recommend swapping the oil out after 3000 miles (presumably due to sludge being released into the oil). So I might put this stuff in, along with some Lucas oil conditioner, and do another oil change after about 1000 miles (I'm assuming there's a bunch of crud in there, based on how PO owner treated this car). I'll keep you posted on how it worked with the leak....

 

Do not run extended drains in these trucks, they run way too rich. I know synthetics make it possible to run longer due to the oil not breaking down, but these get way to dirty.

 

Mobil 1 Highmileage works!

I don't know why someone didn't make a sys highmileage years ago.

 

At what mileage is the Rover 4.0L considered to be a high mileage engine???