I could use some input on what you all think the problem is. My 2003 4.6L Eddie Bauer 4x4 Explorer is burning 2 quarts of anti-freeze and 1 quart of oil every week. Its not over heating. It runs fine. There is no oil or anti-freeze leaking out onto my garage floor. The immediate thought was head gasket but we used Napa "block tester" coolant leak test and it showed that the head gasket was fine. We had someone tell me that he had heard of the water pump valves going bad which caused this and someone else told me that he had heard of the intake manifold or gaskets going bad which would cause this. Its been doing this for a while so now its throwing a catalytic converter code so I assume its filling it with a bunch of crap since its burning all that oil and anti-freeze. Any ideas on the problem is appreciated.

 

If its burning antifreeze and oil, it is probably the head gasket. There are addatives you can put in to seal up the antifreeze, but the burning oil is a big problem. You should probably consider having the heads removed, tested, and change head gaskets. At that time you will get new manifold gaskets installed. Normally a manifold gasket or crack will not cause that kind of oil burning.

 

I too think it might be the head gasket but the Napa Block tester did not turn colors. What additive would you suggest I add to the antifreeze to seal it? I am just wanting to try a couple quick fixes before I pull the heads. I replaced the PCV valve but wonder if the PCV system is clogged. Where is it on my 4.6 and how do I clean it? I am also thinking about doing a compression test. The engine has 165,000 miles on it and I have been running Mobil 1 extended performance high mileage sythetic oil. My engine is also full of sludge so I was considering adding a product to my oil to help clean it out. I know you want to dissolve the sludge slowly because it if does it too fast a chunk could break lose and clog up your engine. Which do you recommend out of; Auto-RX, Seafoam, Liqui-Molly, Kreen and Marvel Mystery oil? Click the link below to learn more about Napa Block tester.

https://www.napaonline.com/napa/en/p/BK_7001006/

 

Coolant does a great job of cleaning carbon from spark plugs and pistons. I'm not sure how effective the coolant would be and cleaning a cylinder if that same cylinder were also burning oil though. The spark plugs though are very easy to get to on the 4.6L so I'd recommend you pull all 8 spark plugs and check for any that are abnormally clean or abnormally wet/oily. Maybe you'll find one of each. Then if you have access to, or don't mind purchasing, a cylinder leakdown tester, you could get each suspect cylinder to TDC and try the leakdown method. If you get leakdown with the valves closed, you can be pretty sure the issue is not an intake manifold gasket. In that case you should be able to see/hear the air escaping in to either the cooling system or through the dipstick tube or oil fill cap. At that point you pretty much know that either you have a head gasket issue or a block issue.

-Rod

 

The spark plugs were clean and dry plus it does not smoke at all. The guy who looked it over suggested that I just keep driving it until the problem gets worse and that way we will hopefully be able to find out exactly what the problem is. He said he thinks the problem is twofold. One the intake manifold gaskets are bad or the intake manifold is cracked. Secondly he thinks the oil burning might be PCV related since the engine is full of sludge. That is one reason why I replaced the PCV valve but think that maybe the PCV system is clogged. Anyway he said he would be glad to take the intake off and replace the gaskets but said he didn't like the idea of wasting my money when that might not be the problem.

 

Does the truck run fine other than the check engine light being on for the converter codes? You mentioned in your first post that the truck is burning the coolant and oil and a pretty high rate (depending on how many miles you drive a week) but in your most recent post you said it doesn't smoke at all. Do you smell either oil or coolant burning? If so, does it smell more like it's burning through the exhaust or from under the hood? To be going through that much coolant a week (again, depending on how much you drive a week) I'd expect that you'd either have really clean spark plugs, possibly with a green tint to them, or you'd smell it burning under the hood.

-Rod

 

Yes it runs fine. There is actually no smell of the exhaust or the sweet smell of antifreeze under the hood when idling however if I am driving down the road and floor it then you do smell exhaust fumes in the cabin but there is also a hole in the muffler too. We only drive it around 150 miles per week so its definitely burning the oil and anti-freeze at a very fast pace. Yes the spark plugs were very clean when I pulled them.

 

you can seal coolant leaks in the head or gaskets with BARS COPPER head gasket SEALER... I think the number is 1109 ? It mixes right with the antifreeze, no flushing.

 

check Auto Zone or others.......

https://www.amazon.com/Bars-1109-Liq.../dp/B002PX91OG

 

Update: We finally found the coolant leak. My freeze plug is leaking. The problem is that its on the back side of the engine down by the rear main seal. That means we have to take out the transmission and fly wheel to replace it. I'm looking at over $1,000 for replacing a freeze plug that costs less than $10. So what would you do? See if a coolant system sealer such as K-seal, Conklins Dike or Bars Leaks stop leak concentrate will seal it or would you just bite the bullet and drop a thousand bucks by replacing the freeze plug?

 

depends on how fast it leaks and how much.. If its a fast drip with little pressure, the sealer will work.. If it squirts out under pressure, that is hard to seal... $10. compared to $1000........... I would try it... Problem is if the plug is rusted out, it may get worse long term.. If its a localized pin hole, it should work.

 

Why is there a freeze plug behind the flywheel? That seems like the dumbest place to have one...Usually your freeze plugs are in the block along the length of the engine underneath the cylinders...Considering they are made out of fairly thin metal, I can't think of a reason why they would have the casting so that one would be hidden there....wow.

 

I did some more research before we go through the huge expense of dropping the transmission to replace the freeze plug in front of the fly wheel. I found that many assumed the freeze plug at the back of the engine was leaking when they saw coolant by the rear main seal.

However, some noted they have seen coolant leak down from intake manifold due to the gaskets being bad or the intake manifold being cracked or because the coolant pipe that runs below the intake which connects the heater core to the water pump was leaking thus causing coolant to leak out the back of the engine and made it look like it was coming from the back freeze plug when in fact it was not.

The check engine light went out and it quit burning oil after I replaced the PCV valve. However, when I sprayed Seafoam into the hoses that lead to the intake manifold the check engine light came back on. Below is what I am thinking of trying next.

I plan to add coolant sealer to the coolant system. To make sure we don't clog everything up I would like to flush it, then temporarily by pass the heater core and take out the thermostat. Then add the coolant sealer and let it stay in there for a couple weeks. Then we can drain the cooling system, hook back up the heater core and thermostat. Then we can fill it back up with fresh coolant.

If it still leaks then the next thing to do would be for us to pull off the intake manifold and see if the gaskets are leaking or the intake manifold is cracked or the coolant pipe below the intake is leaking.

 

coolant sealers 20 years ago were an oily slime that plugged up internals... THe new stuff like BARS COPPER only forms a plug when it goes from the pressurized coolant passage thru a very small orifice, drops pressure to atmospheric, and hits ambient air... There is no pressure drop across the heater core so you should not plug that. I was worried also, but I have done it several times over the past 10 years and never had a problem with the heater core afterwards... Some sealers will mix with the antifreeze and do not need to be flushed.. BARS COPPER is one of them.... to each his own.

 

You want to know were it is leaking. Well I have made a fair living off leaks this tool will find both Antifreeze and oil as well as many more. Drain the antifreeze and put the output smoke in the radiator fill and look for smoke coming out probably from the intake manifold. And for oil put it in the fill tube or dip stick or even the pcv anywhere the oil travels. And for very tiny leaks like pin holes in vacuum lines you can add automotive dye and there isn’t a leak any were in the automobile and other sealed systems that can hide its location from you.