Synthetic oil leak! Experience needed!

[T4R2014]

Seems to me that everyone on this thread is in total agreement on the fact that synthetic oil isn't the problem.
But there is really only one good solution.


I have no doubts that the "Stop leak" stopped the leak but in my experience ANY kind of stop leak be it for the radiator, power steering, or oil is always a bad idea.
They "work" alright, but they have mucked up the properties of the fluid that they have been added to.

I would drain that manure out of your system asap and replace the gasket with Toyota Black RTV or Permatex Ultra Black RTV. Get a new washer for the drain bolt.

I would drain the oil, drop the pan, clean it out, check the magnets at the bottom for metal.
Clean the old gasket/RTV off completely, lay on a nice bead of just RTV no need for an actual gasket and tighten properly with a torque wrench.
Get some cheap "sorta synthetic" that has a good detergent package in it and use that for about 2000 miles to help clean out more of that stop leak, drain and replace with "real synthetic" like Red Line or Amsoil.

Should not cost more than about $10 total (to fix leaks) and about 1 hour of your time.
If you do not have the place to work on it then probably cost you about $75 for a mechanic to do exactly that.

" "

I am sure it does, you know what also would do that, SAWDUST or Super High Viscosity oil like old used car shysters used to do and probably still do to make the engine or trans sounds better for a short period, long enough to sell it to a sucker.

Nunyabiz speaks the truth. There is no magic in a bottle. If it was so good, then everyone would use it. Not changing the seal is simply half-assing the job IMHO. Also, your thread is titled "Synthetic oil leak! Experience needed!".

 

[Nunyabiz]

I never said or implied that synthetic caused leak. If you were one of the few to read it correctly you'll see me state several times that I wasn't saying it was synthetics fault, I was saying that because of synthetics properties of cleaning better that the leak became noticed. Basically synthetic oil was the magician that took the rabbit out of the hat, the rabbit was always there but I couldn't see it. I hope that clarifies it for everybody flaming me..

I thought you were very clear on that in the body of your post, I think what may have confused some was the Title ""Synthetic oil leak!" as T4R2014 stated.
But the point is that you should make sure that it is even really leaking from the oil pan gasket. It is possible it could be leaking from someplace else and just appears to be from there.
Dropping the pan could be a pain in the arse, kinda depends.
But unless you have a nice garage, a way to get your truck in the air so you can stand under it, it will probably be a pain in the arse. I was thinking of the transmission pan earlier, that is fairly easy.

So I would get about 3 cans of Brake Clean and clean the hell out of everything around the oil pan and above it and make certain that is even where the leak is.
Maybe even use spray foot powder around the usual suspects so that a leak will show very clearly and immediately on the white powder.
In general oil pans rarely leak IMO, unless the pan was hit.

Now that this Stop Leak is in there it may be harder to tell.
But as far as I can tell the only thing this manure could possibly be doing is just changing the viscosity of your oil, making it thicker.
If it "swelled gaskets" or anything like that then you wouldn't have to keep adding it to every oil change like it says on the "Technical Data Sheet".
So if that is the case then just use a higher viscosity oil in the first place like maybe a 15w50 Synthetic racing oil.
Will do the same thing but better, probably run like Butta but you will probably get about 8mpg. This engine was designed to run on 5W30 for a reason.
IF the leak is coming from someplace with a cork or type of gasket that needs to be wet to seal then there is just as good a chance that the synthetic oil could reswell the gasket unless the gasket has been dry too long and fried.
If its really coming from the oil pan then it is always going to leak unless you just need to tighten a few bolts. But I would question why the RTV started leaking in the first place.

http://lucasoil.com/images/documents/TDS_Engine-Oil-Stop-Leak.pdf

AMSOIL DOMINATOR® 15W-50 Racing Oil

 

[T4R2014]

This engine was designed to run on 5W30 for a reason.

Not necessarily. If you look at oil recommendations for the 5VZ in overseas applications you will find that regions such as Europe will recommend 10W40 and even 15W40. In Australian applications they will even recommend 20W50, I'm guessing due to high heat conditions. The 5VZ seems to have been designed to work on a wide range of oil grades. I don't see why OP can't use a thicker oil.

 

[MarkinWMich]

Not necessarily. If you look at oil recommendations for the 5VZ in overseas applications you will find that regions such as Europe will recommend 10W40 and even 15W40. In Australian applications they will even recommend 20W50, I'm guessing due to high heat conditions. The 5VZ seems to have been designed to work on a wide range of oil grades. I don't see why OP can't use a thicker oil.

Exactly.

Excuse my "layman's vocabulary" here:

With 170K on the engine, there is bound to be some wear, gaps have widened, and the thin 5W oil, especially, synthetic 5W oil will flow a little "too easily" between those parts, lowering the regional oil pressure. Oil pressure may vary at different points throughout your engine, and your oil pressure guage measures oil pressure at one, and only one, point. This, in turn, may cause some of those critical, "tight" areas to be neglected of proper lubrication. Fluids will always flow in the direction of least resistance. In other words, oil will flow through a large hole or gap before it flows through a small hole or gap.

Using a higher weight oil, like a 10W or 15W synthetic in a high-mileage engine may restore the regional oil pressure and allow oil to be squirted into those critical, "tight" areas in the engine. So, in terms of prolonging the life of your high-mileage engine, it may be to your advantage to use the higher weight synthetic oil.

 

[pluton]

But the point is that you should make sure that it is even really leaking from the oil pan gasket. It is possible it could be leaking from someplace else and just appears to be from there.
[/url]

Recently, I changed the oil and filter. M1 5W-30 High Mileage, and a K&N filter.
HM oil because I had become a victim of the psy-ops of the marketers, and the K&N because the the nut on the filter helps me remove it next oil change.
Soon, there was an intermittent but serious oil leak. It would drip five drops one day, and blop out a third of a quart another day.
From what i could see looking at the vehicle above and below, it would have been credible that the leak was coming from the oil drain plug, front crank seal, rear main seal, oil pan, or valve covers.
Turned out it was the oil filter!
Defective gasket, or some crud between the gasket and the mating surface.

 

[Nunyabiz]

Not necessarily. If you look at oil recommendations for the 5VZ in overseas applications you will find that regions such as Europe will recommend 10W40 and even 15W40. In Australian applications they will even recommend 20W50, I'm guessing due to high heat conditions. The 5VZ seems to have been designed to work on a wide range of oil grades. I don't see why OP can't use a thicker oil.

Cool, did not know that, however I can guarantee you will get less MPG using a 20W50 than you would a 5W30.
But if that the case then running a good 15W50 synthetic racing oil should do the trick without any problems.

 

[Amirocassar]

Yeah I was even thinking the other day that the leak could also be caused by me dropping to 5w-30, I had 10w-30 in the before, but I was in Texas and now I'm in NJ. I know 10w-30 would work fine since it doesn't really go into the negatives up here, but with my luck I would put 10-30 in again and we'd have a nice age winter... My luck is just always terrible. I appreciate all the responses and apologize for the title confusing people, but I am no way ignorant and blaming synthetic. I have noticed a significant increase in MPGs though. I've been driving 52-60 miles a day and use to use half a tank after maybe 2-3 days(if lucky). But instead I got like 4 days plus miscellaneous driving out of a little over half a tank... Which just astounds me! I went from 150miles/half a tank to about 250miles/ a little over half a tank. Anyway, now I'm debating to stick with synthetic next change or go back to Dino oil. I just can't afford to change all the seals, I don't have the time to do a major project like that. I bet that's something in the 2k range. That's roughly 1 1/2 months of work for me at walmart. I even inquired about timing belt/water pump change at an auto shop and they wanted 800. Stealership wanted 900, so far it looks like it'll be 400 bucks for all OEM parts and tools(torque wrench, pulley holder, some deep sockets, ). Thanks for all your help and opinions guys!

 

[99ToyoRunner]

I bought my 99 4Runner from my friend who did regular oil changes but I doubt he used synthetic....I always use synthetic and have been using it for over 10k since I bought my truck...no leaks..no problems.....I should mention that my truck has 166k...she doesn't use a drop of oil between changes which is every 5k