Hi all,

2006 4.0 SOHC 80000 mls. Bought the car with "milkshake coolant", got the heads machined (they were off), did the cam drives while it was apart, all new gaskets, in fact followed the (brilliant) youtube video series from FordTechMakuloco to the T... Today I filled it up with coolant. I have one of those coolant burp thingos on the radiator and kept filling it up... and up... and up....

At some point, I cranked the engine for oil pressure, then connected cam sensor and it started up. Sounded like it was running on 1 cylinder... I thought it would get better but no go. Shut it down, rechecked...and noticed coolant coming out of the air filter housing! FFS! Drained the coolant, then the "engine oil" or should I say 10 L of green coolant followed by a looong stream of peppermint coloured milk shake. Mind you, the total running time was less than 1 minute. How can this happen? It couldn't have been worse if I had filled the coolant directly into the oil spout, not to mention that the burp cup kept draining and draining...I could have kept going. Where did I go wrong? I mean the heater hoses are all pretty much pre-bent and cannot really be confused with anything else, can they.

I am gutted... any help appreciated.

Thanks,

Thomas / Brisbane, Australia

 

Wow, and I thought I was having some bad luck. May yours improve.

 

Bummer, big time

Leave the oil drain plug off
And start filling radiator with water
See how soon water starts to come out of drain plug
If its right away you could have a cracked block, extreme long shot, but not a no shot

In this picture: https://cimg5.ibsrv.net/gimg/www.ran...d84eab8cb7.jpg

On the right with green circles are coolant lines, but between them is the PCV hose, Vacuum hose

There could be a cracked intake, that would explain coolant in the air filter, but head leak could cause that as well by pushing coolant out when intake valve was open

Pull out all the spark plugs, crank engine over, it fine to do that without oil a few times
See if one or two spark plug holes are spewing water more than the others, that would point towards head gasket issue

 

Thanks, will do. Because of the speed the water runs into the block (I would guess about 2 quarts / minute, it's gotta be quite a crack... Will keep you posted.

OK, just a quick test in the morning, later more; I pressurised the radiator with air and it was coming out of the oil filler spout and the drain plug. Drain plug seems to be more direct. I put a rubber glove over the spout and it barely inflated. Anyway, back to more tests. Cheers

 

Still nothing new. Tomorrow I will blow some compressed air into the sump so hopefully hear where it comes out. Also a compression test wouldn't go astray. Before that I will try the water filling test you suggested.

Again, it was leaking or better pouring into the engine only by atmospheric pressure, ie while I was filling it with 20+ quarts of coolant... if I hadn't stopped, I would have filled the whole engine. So with that in mind, what would be the most likely meeting point? Those 2 holes of the water pump? What else? Mind you, I replaced the thermostat housing for a metal one and obviously had the front and rear cam drive cover off. Heads were off as well and so were the 2x oil sumps. They were all put back together as per Makoloco video using a new gasket kit. I filled up the oil a few days ago and no leak out of the engine anywhere. I mean I could have caused a leak somewhere but something that drains gallons into the oil within minutes even when the engine is not running???
Are there any water passages in the big plastic intake cover thing (for lack of better word)?

Anyway, it will be a merry xmas... it's freakin' hot here at the moment...
Cheers

 

Yes, there is coolant in the intake, that's where the thermostat housing is, and it passes coolant between the 2 heads
But its above water pump and head levels
Water pump would be the lowest coolant level with access to oil pan area, then heads then intake as the highest

The coolant would have drained out but only to the level where the breach between cooling system and oil pan is
So there should still be coolant in the lower block, unless you have removed lower radiator hose

There should be a heater hose connected to the water pump, pull it off and see how much coolant comes out, if its a lot then leak is above water pump level, if very little comes out then water pump to block passages are likely leak point

 

Thanks mate. It's 3:45 AM over here and this sh!te is is doing my head in. As you know I drained the coolant immediately but yesterday thought maybe the heat exchanger/oil cooler is to blame. Not sure if you guys have that, it's like a sandwich style thing connected to the heater cycle... when disconnecting it coolant came out, but only what was left in cooler and hoses. I guess I have to refill again. Either way, it's not the oil cooler.

From memory whenever I squeezed the upper radiator hose, even after the 20th quart, bubble came out of the burp cup...

Anyway, will follow your advice today, refill, maybe I can figure out the level. At some point I willl put some cheap oil back in for protection and leave the coolant out. The compression test etc.

Again, your help is much appreciated...!!!

Cheers, Thomas

 

PS: as per what you said about "head level", keep in mind the burp cup, depending on it's water level, it adds quite a few cm to the level height. Here is a pic.

https://i.ebayimg.com/images/g/DgkAA...J7/s-l1600.jpg

Lastly I am still having a problem wrapping my head around where the water pump and thermostat housing could have access to the oil? Or in other words, where would they have to fail to let water into the oil? I can imagine them dripping water ie leaking to the outside...

 

Maybe the next course of action would be to remove the oil pan entirely. Get under there while a friend pours water into the radiator.
Make it ice water so you have the increased shot at detection by feeling the cold.

Have you any 'gauge' (meaning reference point) of "completely empty"? In other words, do you have a handle on any of the "water level" comments made?
Since you're pouring "20 quarts" of water in, it might be you're filling the oil pan first then the level rises to your "external leak".

Could this be some odd case where the water pump impellor wore a hole into the block? I don't know if that can occur with these engines.
How 'bout a previous repairman mixing up water pump bolt lengths and punching a hole where one shouldn't be?

Anybody down there add an oil cooler? It was 54.5*C (yes, 130*F) the Christmas I was there (2001-2002). Everywhere I went was like a ghost town.

 

OK, quick update. I refilled the radiator this morning. Sump screw out, system was drained by removing the lower radiator hose, oil empty. The system is supposed to take about 3 gallons (I am using a 4 liter container... Australia... metric, 4 liter is a tiny bit more than a gallon).

1st gallon... no leak.
2nd gallon... leak started almost immediately and drained the coolant through the sump hole with roughly half the speed of the burp cup refilling it. Put the 1 gallon container under the sump hole and was able to collect about 1/2 to 3/4... SOOOO... water pump? At that speed?

Anyway, will take it off later, currently struggling with the fan I stupidly put back on. Have to make another tool...

Btw, I found photo below from when I first disassembled the engine before removal. Have a look at the oil puddle... that shouldn't really be there, should it? Maybe there is a hole in the block somewhere, where else would it come from (still failing to understand where the water pump intersects with the oil)?




Cheers, T

 

Thanks mate. Only the heat exchange cooler, which I originally thought was leaking. The root cause of all these problems in my opinion was whoever installed the LPG system. Apparently, the LPG needs to be preheated so they took off the hoses from the sandwich oil cooler... which then caused the thing to overheat and warp the heads. Along come I, buy the car for cheap (it's a Mazda B4000 2wd with only 60tmls for $1700 US) and think "I can fix that..."... and here we are. It's pretty hot atm, I am in Brisbane, but not 130F.

 

Here is a picture of the front of a 4.0l SOHC with front timing chain cover off: https://www.explorerforum.com/forums...019-jpg.84924/

The larger holes on the left and right are the water pump passages to the block...........................and that's the open oil pan at the bottom

 

Thanks Ron, got ya. I thought we are talking about the water pump somehow failing internally and leaking water into the oil. So the leak would have to be the gasket or seal which brings me back to my original worry, ie the speed with which it leaks. Together with the oil puddle on the pic I posted I am guessing a pretty big hole in the waterjacket somewhere. Anyway, I will take the water pump off later today or tomorrow morning.

With the water pump removed, if I were to plug one of the 2 holes and blow into the other and the was NO holes in the block, the pressure should hold, right?

Thanks again. T

 

Yes, with water pump off and as long as the upper radiator hose and water pump heater hose is also blocked off, the system should hold pressure, 16-20psi is what it is rated for

The water pump has an inlet and outlet, and it circulates coolant from its outlet thru the block and heads and then back to its inlet
But...........there is a thermostat on the upper radiator hose, its closed when cold, but not air tight

And there are heater hoses, but they are a closed system, if water pump is in place, with water pump removed there will be an open heater hose, that also needs to be blocked off

 

Thanks mate, heater hose... good point. Running late now, should get that done tomorrow. Thanks again. T

 

Hello,

Have I just found the problem?



Just had a look at some of my hose connections and they don't make sense. To my defence, the car had LPG with about 3 mls of hoses plumbed into everything... and I also replaced the thermostat housing. Anyway, pls have a look at he pic. Red is connected to red, I think it's some sort of vent hose... and ends up in the EGR valve (?). Blue is connected to blue, ie one of the heater hoses. Here is where it get's weird. There is a junction from the heater hose....coolant... which I have connected to the EGR... that can't be right? The EGR has 3 inputs, 1x big and 2x small. Big one has red vent and 1x capped off. If not the connection to the heater circuit, what goes into the 2nd one? And lastly, what goes into the heater hose junction *ie blue / green)? I may be on to something. If not... please just lie to me.

Awaiting your answer with baited breath.

Cheers,

Thomas
OK, 1 hour later. Apparently, EGR valves need cooling, which is why engine coolant runs through them... I really thought I had it. Anyway...

 

Never heard of an EGR valve with coolant lines, PCV valve does have a loop with 2 coolant lines, smaller ones, then a larger vacuum hose at the top, looks like this: https://www.partsgeek.com/assets/pro...n/P1RS97Y5.jpg
Coolant is to Heat the PCV Valve so it doesn't get clogged with oil vapor

EGR Valves just have the 1 vacuum hose connected, unless they are electric then no hoses at all

The green and red circles are coolant hoses: https://cimg5.ibsrv.net/gimg/www.ran...d84eab8cb7.jpg
On the right between the 2 green circles is the PCV vacuum hose

So in your pic the 2 red dots are connected together, PCV Valve hose, runs around the back of the engine to PCV Valve on the other valve cover

 

OK, so Blue is a vacuum hose, unrelated to my problem, connects to Blue.
Red is a coolant hose (which goes to the heater core), connects to red, which I falsely called EGR valve
Green is blocked off BUT should be connected to the other hose that goes to the heater core as per your pic.

Hmm, so I am missing the return hose, what probably is not the fix for my leak...

Aaargh

 

Small suggestion.
The heat loop (aluminum tubing) around the PCV valve is supplied hot coolant via smaller hoses.
Removal of that setup has been mentioned by owners over the years. Some people claim this heating loop is ineffective. I can't comment on that but mine is intact.
There's another "trident fitting" for that coolant (to supply the PCV valve's heat loop) which resembles the one in the center of the photo in post #18 above (with the green and red dot on it).
Trace those small hoses back to the larger hoses which feed them just to locate, identify and remove them from your search.

 

Thanks, would make sense to remove the heating loop in our subtropical climate, if anything , things need cooling.

 

The worth of the heating loop is argued. I think keeping the PCV from clogging is a good thing.
My point is that zealous retrofitters (the LPG people) may have changed some hoses' routing for the worse.