What say you about a Ford 4.6? (smoke, low oil and coolant)

2006 E250 EB with the 4.6.

Checked the fluids today. Losing some coolant (it was low about 1/4 gallon after 2k miles), some oil (roughly a quart at 2k miles), and

Since I've owned it, I've noticed occasional white/light gray smoke coming out the exhaust. This happens intermittently, usually when the engine is warm, and usually when low RMP, high throttle situations, like when backing up, for some reason. It will also do it in Park sometimes if I give it a half throttle or more in Park.

I'm wondering if its burning coolant or oil. I see no leaks of coolant, but do occasionally smell it, and a very minor oil leak at the oil pan. Engine has about 120k miles, and is a rebuild/re-man'd motor. Chassis has 335k.

Any common places to look for coolant leaks?

I'm wondering if the smoke is from oil or coolant burning. Maybe the quart of oil loss isn't a concern, but I'm curious what you all think.

Any other thoughts?

White smoke is coolant.  Blue/gray smoke is oil.

First place I would look for a coolant leak is the head gasket if you're getting white smoke.  Sorry for the bad news, but one quart of oil at 2k miles wouldn't cause visible smoke.

Thanks, I have wondered if its a HG issue. It's honestly hard to tell if the smoke is white or gray/blue. I'll try to get a better look at it by having my wife drive it with me outside. I hear you though that the quart of oil wound't cause visible smoke.

Is there anyway to tell if its the head gasket and which one?

I always do head gaskets in pairs.  If one has failed, the other is likely not far behind.  As long as you're taking all the top end apart, it would suck to have to do it again.  While you're at it, get a new passenger side exhaust manifold if you haven't already.  Dorman makes one.  The factory one will crack if it hasn't already.

You can pick up a coolant pressure tester at HF for cheap.  It screws on in place of your radiator cap and has a hand pump to pressurize the system.  If it has a leak, it will bleed down.  Hopefully it's external and you'll be able to see where it's squirting coolant.  If you lose pressure and there aren't any puddles, I would start pulling spark plugs and putting a boroscope in each cylinder.  If they don't show coolant leaking, that's good news.  If it's burning coolant, you'll also have one spark plug that will look lighter than the rest.  The water kinda steam cleans that cylinder

I think they still sell test strips that let you test oil to see if there is coolant present.

It's also possible you have an intake gasket leak that is allowing coolant to make its way to an intake port.  They're pretty close on those heads. 

You can also get a spark plug adapter tool that lets you hook up an air hose.  Make sure to rotate the engine to where both valves are closed and pressurize each cylinder.  If you get bubbles in the radiator, bingo.

Coolant leak in a mod is 95% the intake manifold/gaskets.  Usually the driver side, sometimes passenger, always fills the spark plug wells with coolant.  It often drools back, not down, and evaporates off before it hits the ground.

Oil leaks are... numerous.  Have seen the coolant/oil gasket at the oil filter/lower radiator hose housing leak. Have seen external head gasket leaks (easy to see with doghouse off). Have seen oil pans leak, both gaskets and pan rust-through.  Have even seen a failed tensioner pulley chew a hole in the timing cover and part of one of the chain guides. And one crank sensor leaking oil through its housing, drooling out from the connector...

Thanks Pete. Would that intake manifold/gasket leak lead to the smoke I'm seeing out the tail pipe?

Also, would it contribute to the left bank cat going kaput?

Not at all for the smoke.  Or the converter.

At 335k miles and who knows what happened to the original engine that warranted its replacement, I wouldn't stress too deeply about the converter if it's OE.  And if it's aftermarket, those usually have short lives regardless.

Remans are usually not very good. Ive seen weird failures on big name remans (not by the OEM). That said as someone mentioned its almost always the intake manifold. If you can afford for it to be down for a little pop the manifold odd and inspect the crossovers at the front and rear of the head. You can get pitting on the aluminum or a gasket failure and let it suck a little coolant into the neighboring runner. Do not pressure test one with a potential intake leak. I have ejected a rod because I lost pressure and couldnt find a leak, well it all went into the rear cylinder and we all no water doesnt compress.

If you see no problems with the intake/crossovers truthfully I would ignore it after that, maybe throw some seal tabs in the cooling system if youre that worried. Ive seen plenty of oil consumption on these since they where new. If you have no drivability issues ive seen 4.6s go a long time with negligent owners, just keep fluids in it and just see if it gets worse. A friend has been daily driving a high mileage crown vic with a blown head gasket for over a year, he just tops the coolant off occasionally. 

In reply to Pete. (l33t FS) :

Thanks, it sounds like I can just replace the cat (which is OE) and not worry about whatever issue is happening ruining the next one. So you're saying the coolant in the manifold would not cause smoke, correct?

If it's not the coolant leaking into the intake mani, I'm still wondering what is causing the occasional smoke. It's so strange. Very intermittent.

Yesterday I experimented with it. I revved the engine, full throttle in park, smoke. Then again after getting gas, same input, no smoke. Then did it 20 minutes later, smoke again.

I'm thinking it might be blue smoke after all. Hard to tell from the driver's seat. I'm going to try to get a picture of it soon.

@Opti, thanks. Good to know about all that. And I'll take a look in there when I have more time.

In reply to CyberEric :

I have never seen an external coolant leak get into the intake manifold.  If it could do that, it would also have a bad misfire and rough running from the massive vacuum leak, which is a much larger concern most of the time.

That makes sense, thanks. The engine runs quite well. Only the smoke issue, oil and coolant loss, and the bad cat.

Just want to make sure I am not going to ruin another cat really quick if I don't address.

In reply to Pete. (l33t FS) :

I have personally multiple cars that leak at the crossover and the coolant be sucked up by the adjacent runner. Not the common failure mode, normally it's external but I've seen it more than once.

No real noticeable drivability issues. Did have slow but steady coolant loss and sometimes light smoke.

I've also seen 4.6s consumer oil since new and forever and noy cause any problems besides needing a quart here and again

This is one time where UOA can help. You'll see  signs of coolant in the oil way before it's something you can see and smell. 

I had an '01 Mustang GT with the 4.6L and 5spd.  I noticed a puddle of coolant right under the crossover.  I pulled the intake, ordered a new FRPP one, and discovered that it wasn't the crossover that was the issue, it was a bad intake gasket.  It was definitely worth replacing the original, plastic-crossover intake manifold that had 294k on it at the time, though! I didn't have any symptoms other than the coolant puddle on the front of the motor.

In reply to bobzilla :

I like that idea, thanks!

In reply to CyberEric :

The 4.6 Valve Stems are known to fail. Check those first.