Hemi Oil Leak

[markhall3]

Hi, I have a 2007 5.7 Hemi, 42,000 miles. Switched oil to synthetic from MotorCraft 5-20.

Developed an oil leak on the left side of the engine above the starter, I think.

Hope it is not a rear main seal. Notice one - two drips on the garage floor....back of oil pan is wet...

Question...could the synthetic oil cause the leak?

Thanks,

 

[tinmanSC]

The only time a synthetic can "cause" a leak is if you have an issue with varnish or deposits on the seal, and the detergents and dispersants in the synthetic may clean it off. This has given synthetics the reputation of causing leaks, but it's not really what happens. It's just because they generally have higher detergency levels. Since this engine has low miles, are you sure you didn't just run over something dirty? try cleaning off the back of the oil pan and then check it a few days later to see if it comes back.

 

[markhall3]

Hi,

I cleaned the back of the engine on the last oil change. I'm sure I did not hit something. I just developed a leak. I might go back to the Ford oil again. The synthetic makes the engine run smooth and quiet. I like the oil, but not sure a seal does.

Thanks...

 

[NHHEMI]

The poster above is 100% correct. Synthetic in and of itself does not cause leaks. It can clean things out so good and so fast that it allows a current condition to appear/get worse which makes people think it is the oil however. You either had an exisiting leak/vulnerable spot that became visible after the swap or it is a coincidence that the leak started after the swap.

 

[SteveSRT8]

The one thing I can assure you about the new gen Hemi is it does NOT leak oil. Very few newer engines do.

You have a very rare occurrence there my friend. I really doubt the oil caused that issue.

 

[Kuato]

A couple of drops shouldn't be a worry, unless it continues.

I've switched several post-2000 engines to synthetic from dino, at mileages varying from 25k up to 90k. The 90k developed a small leak, which went away after the next synthetic change. As tinmanSC said, if you had some buildup/varnish from the dino you were using, it's likely the synthetic is cleaning it out, and the leak should stop as soon as it's done.

 

[hounddog]

Is not all 5w20s mostly synthetic? The oil didn't cause your issue.

 

[Spector]

Give it some time. I have seen where initially the switch will seep some oil but that it stops after several thousand miles. You can wait and see as it is only seeping a little.

 

[demarpaint]

Are you sure the oil isn't running down from the back of the one of the valve covers? Just a thought. I doubt the oil caused the problem.

 

[Scout1]

I don't mean to be a troll here, but I was reading about the new GF-5 and ACEA specs for 2010 and I see a number of tests dealing with how the oils impact rubber. I've also read about synthetic oils causing some seepage and even noticed that on my FJR motorcycle when I've used synthetic. I get seepage around shaft seals that I didn't notice before.

Just sayin...

 

[mechtech2]

Oil drips down, then hits the floor.
What I mean is that a leak may be all sorts of places upwards and sideways of the actual drip off spot.
A good cleaning and spray baby powder can help determine leak sources. So can a dye and a black light.

As to synths causing leaks only with false seals that are cleaned...NO.
They can and have caused leaking in otherwise perfect engines. I have seen side gaskets blow out, and all sorts of leaks start when switching to synth. It is not normal or usual, but it DOES happen.
My own engine is one of them. Minor leaks have happened with with some full synth, and none with dino/dino blend.

 

[markhall3]

Yeah, I think it could be a head gasket....valve cover is dry.

I'm going to change to a different oil. I love this Valvoline and so does the engine, but will try a high mileage oil or regular dino.

 

[fdcg27]

Let me ask a dumb question.
Isn't this thing still under warranty?

 

[stenerson]

120K miles on my 2004 hemi no leaks yet. Been using synthetic since I bought it with 52K miles. I spend a lot of time at forums with hemi drivers and oil leaks rarely an issue.