Way overfilled oil

2006 mustang GT 95k miles

A couple days ago while driving my car out of the blue began overheating. I've never had a cooling issue before so I didn't notice until it was already deep in the red. As I slowed down I noticed smoke coming out of my hood vents. Coolant was full but I noticed oil leaking, which looked like it was leaking from the oil pan gasket.

I started up the car today to move it a few feet up my driveway, and when it started the engine was making a new ticking noise. I figured that the car may have been burning oil and that the first thing to do would be an oil change, so I drained the car and found that when I measured it out, there had been 8.5 quarts in my car, plus whatever amount of oil had leaked or burned off. I do all my own oil changes and have never added more than maybe 6.1-6.2 quarts to my car.

Now, without making the story too long, I (used to) allow a friend of mine to drive my car from time to time , and when I asked him if he had done anything, he essentially said that he had been regularly adding oil without checking the level, because he had seen smoke coming out of the exhaust when driving hard and thought that it may have been burning.

So I've now replaced the oil and put in the proper amount. I haven't let the car run long enough to check if it would still overheat, but when I started it I could definitely still hear a tick, which sounded like it was coming from the valve covers. I also could still see oil dripping when I looked out of the car, but this may have just been the previously leaked oil warming up and dripping off.

My question is what do you think may have been damaged? Aside from likely replacing the oil pan gasket, what do you think was damaged/causing the noise in the engine?

Almost always a blown head gasket.

So some weird things happen when you overfill an engine with oil. First off the crank sitting in the oil will cause aeration of the oil. Once this happens you lose it's lubricating properties so basically it is like running your engine without any oil. Typical low oil damage will occur when you overfill your oil pan. Without proper lubrication the engine will run hot due to increased friction. When this occurs the aeration in your oil will cause it to expand and build pressure and gaskets and seals will fail.

So with this said you could have a multitude of issues. The leaking will probably continue to leak until you find the source. The ticking may be from damage from lack of lubrication.

I would pull the valve cover first and find out what was damaged or why it is ticking. Then you need to have your engine cleaned so you can find the leak.

You let a friend drive the car from time to time and they ran it hard, added oil to it over and over and never told you about it until you had a serious problem with the car? Whew, not much of a friend. Everything that 07Boss said was spot on and you are going to have a helluva time trying to find the one-to-many culprits. My guess is most, if not all of the seals were ruptured because of the added crankcase pressure. Sorry this happened to you, but I would certainly be asking your friend if they are going to chip it for the cost of repair, since well, y'know...they're the one that broke it.

@07 Boss and @Rich have nailed it.
Overfilling the pan leaves the crank bathing in oil. As the crank rotates, all that oil gets whipped up into a froth like a chocolate milkshake. Oily froth isn't very good at lubricating and cooling the engine. The resultant high crankcase pressure can blow seals/gaskets (the oil pan gasket was the weakest link in your case) and push oil past the piston rings causing blowby, hence the blueish grey haze from the exhaust tailpipes.

As 07 Boss said, you'll need to degrease the bottom of the engine to find the oil leak. Since the ticking is coming from under a valve cover, use a mechanic's stethoscope to localise it. Then when you remove the valve cover, you'll know exactly where to look to find the culprit.

Only a complete idiot adds oil to the crankcase without checking the level on the dipstick to make sure it's within the recommended range. DON'T ever let that so-called friend of yours touch your car ever again, let alone drive it. You should also make him foot the bill for the repairs.

Good luck getting your "friend" to foot any part of the bill. Be a miracle if that happens. Your friend is an idiot. Unless he like saved your life as a child or did some other heroic thing to endure him to your life distance yourself from him. He fucked you over and cost you what will be a bunch of money. Best intentions or not he screwed you without so much as a reach around.

Stop loaning your car out to other people. If they don't have an ownership risk, they will treat it with no respect or care.

Pulled the driver's side valve cover but didn't find anything. Pulling the passenger's today but past that I won't be able to do much until the weekend when I can get it inside of a garage.

On a side note, I figured I'd mention it to another buddy who is a ford technician. His opinion was that I'd mostly likely either need to rebuild or replace the engine.

Dino Dino Bambino said:

Only a complete idiot adds oil to the crankcase without checking the level on the dipstick to make sure it's within the recommended range. DON'T ever let that so-called friend of yours touch your car ever again, let alone drive it. You should also make him foot the bill for the repairs.

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I should add that he is actually also my roommate. I'm sure that I'll be able to get most if not all of the cost for this repair from him, but I'd rather not foot him with a huge repair bill, even if it was his fault.

Rich said:

You let a friend drive the car from time to time and they ran it hard, added oil to it over and over and never told you about it until you had a serious problem with the car? Whew, not much of a friend. Everything that 07Boss said was spot on and you are going to have a helluva time trying to find the one-to-many culprits. My guess is most, if not all of the seals were ruptured because of the added crankcase pressure. Sorry this happened to you, but I would certainly be asking your friend if they are going to chip it for the cost of repair, since well, y'know...they're the one that broke it.

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Yeah. Moving forward I'm going to be much more selective about who I allow to drive my car. This has certainly been a learning experience in that regard.

Some weird stuff here.

First off, I have a hard time believing that overfilled oil caused a blown oil pan gasket. Correct me if wrong, but why would overfilled oil create additional pressure at the pan?

Keep in mind that, if the timing cover gasket, valve cover gasket(s) or any other item up top leak, the oil makes its way to the oil pan and might appear as a oil pan gasket.

Personally, I was always told (but never experienced) that overfilled oil would manifest itself first with oil being blown out the dipstick tube.

Secondly, everyone (except LarryJM) is looking past an apparent overheat issue. Crazy cause-and-effect to see oil burning at the same time, though, so I don't know what to make of it.

There are lots of things to unwrap here . . .

An expensive lesson, for sure. I guess the first step would be to open the hood with him and show him where the dipstick is and teach him how to check the oil level.

1950StangJump$ said:

Secondly, everyone (except LarryJM) is looking past an apparent overheat issue. Crazy cause-and-effect to see oil burning at the same time, though, so I don't know what to make of it.

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I've just chalked this up to the oil being overfilled, becoming frothy, and not lubricating properly and therefore causing it to overheat.

Upon removal of the passenger's valve cover gasket I found significant slack in the timing chain and the cam phaser was damaged. I won't be able to tear the engine down further until I get it into a garage.

Another interesting finding:
The dipstick tube wasn't seated properly into the oil pan and was likely a source of at least some of the leaking. I'll deal with all of the oil leak issues after I deal with the timing.

If the tube was not seated correctly, it would give a false “full” reading when in fact it was overfilled.
When I installed my headers, I forgot to replace dipstick before they were in place. The result was I could only seat the tube about 90% in. It does not leak , but it will show a low level, when in Fact it’s full. This could have contributed to your overfill problem.

aren't used 3v mustang engines worth about $.05? 2008+ should have no timing issues.

1950StangJump$ said:

Some weird stuff here.

First off, I have a hard time believing that overfilled oil caused a blown oil pan gasket. Correct me if wrong, but why would overfilled oil create additional pressure at the pan?

Keep in mind that, if the timing cover gasket, valve cover gasket(s) or any other item up top leak, the oil makes its way to the oil pan and might appear as a oil pan gasket.

Personally, I was always told (but never experienced) that overfilled oil would manifest itself first with oil being blown out the dipstick tube.

Secondly, everyone (except LarryJM) is looking past an apparent overheat issue. Crazy cause-and-effect to see oil burning at the same time, though, so I don't know what to make of it.

There are lots of things to unwrap here . . .

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When you aerate the oil the engine will run hot from friction. When the engine runs hot the aeration in the oil expands at a much higher rate than the oil causing crankcase pressure. Yes the oil dipstick is the first place it will try to escape but continuing to other seals and gaskets.

eighty6gt said:

aren't used 3v mustang engines worth about $.05? 2008+ should have no timing issues.

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Cheapest I found was $1800 but that motor looked a bit rough.

I also have a hard time letting go of an engine that I've taken care of for 40k+ miles, and I'd like to take at least take a crack at fixing it before I give up all hope

Laga said:

I forgot to replace dipstick before they were in place. The result was I could only seat the tube about 90% in. It does not leak , but it will show a low level, when in Fact it’s full. This could have contributed to your overfill problem.

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This is definitely possible, but I'm inclined to believe that the dipstick was unseated AFTER the oil was overfilled. Last oil change I did was only a month ago, and adding 6 quarts read as the correct amount when I checked the dipstick.

FWIW, My 3V leaked very slightly from the dipstick tube in the block when engine was running. Very slightly meaning maybe a quarter sized drop on the floor after it sat in garage overnight, from the oil dripping off the bottom of the block or pan. After I saw that drip one time I found the issue so I had to yank the dipstick and put a new O-ring and a small amount of high-temp RTV......no more leak now.

8.5+ qts of oil, instead of 6 qts, what could go wrong ? Let's call it 9 qts. That's a 50% increase...and that's a bunch.

What kind of oil did he stuff in there ?

1950StangJump$ said:

Personally, I was always told (but never experienced) that overfilled oil would manifest itself first with oil being blown out the dipstick tube.

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Older non-OBD engines had rather loose fitting dipsticks so they may have been forced out with building crankcase pressure. Newer dipsticks have an o-ring to help keep crankcase fumes and the PCV system operating correctly.

As the oil foams from overfill I could see the PCV valve clogging and the crankcase building pressure. The pressure will try to escape at the weakest point, be it dipstick, gasket, rear main or other seals.

The first step I would do is to have the oil pressure tested after this incident. If the pressure is bad you're probably looking at a new engine. The crank bearings may be wiped and/or the cam caps, which don't use bearings, may now have too much clearance.

Owners Manual: •4.0L V6 engine•4.6L 3V SOHC V8 engine•Oil levels above the upper hole may cause engine damage. Some oil must be removed from the engine by an authorized dealer.7. Put the indicator back in and ensure it is fully seated.

I realized the original post implies the oil was WAY WAY overfilled.

But, how much overfilled really matters? I have seen posts where folks were going 1qt over for various "internet" reasons. I also remember being told by a service advisor years ago that oil would have to be nearly 3 qts overfilled before it would hurt anything.

My impression is that being overfilled a qt or so will only put you at risk of some frothing and perhaps additional parasitic drag on the crank.

1950StangJump$ said:

I realized the original post implies the oil was WAY WAY overfilled.

But, how much overfilled really matters? I have seen posts where folks were going 1qt over for various "internet" reasons. I also remember being told by a service advisor years ago that oil would have to be nearly 3 qts overfilled before it would hurt anything.

My impression is that being overfilled a qt or so will only put you at risk of some frothing and perhaps additional parasitic drag on the crank.

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Owners Manual: 4.6L 3V SOHC V8 engine• Oil levels ABOVE the upper hole MAY CAUSE ENGINE DAMAGE. Some oil MUST BE REMOVED from the engine by an authorized dealer. Put the indicator back in and ensure it is FULLY SEATED.

He was 3 qts over...that's a bunch...50% to be exact.

Pentalab said:

Owners Manual: 4.6L 3V SOHC V8 engine• Oil levels ABOVE the upper hole MAY CAUSE ENGINE DAMAGE. Some oil MUST BE REMOVED from the engine by an authorized dealer. Put the indicator back in and ensure it is FULLY SEATED.

He was 3 qts over...that's a bunch...50% to be exact.

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Ehhh. The owner's manuals are written by lawyers and corporate hacks as much as engineers. Any single one warning in the manual has a mix of all three agendas, and it's tough to know the respective proportions

And I realize the OP was 3 qts over. That much is a no-brainer problem.