Coolant Dripping From Muffler

[JonD]

I almost hate to ask but here goes... I just bought a 90' XLT 4X4 5.8L. It has a hole in the radiator. Was driven until the radiator blew and that's where I came in. I checked the radiator, yes it leaked. Went to a pick-n-pull over the weekend and pulled out an exact match. Installed and filled up with water first to flush, all seemed well. I then drained and refilled with coolant. Started the truck and let it run a bit to check for leaks. It runs very rough at idle but seems fine at about 1500 and up. Anyhow, after ten mins of watching and waiting I got out and noticed something dripping from the muffler. By this point it was getting darker so I couldn't make it out but it did smell of coolant. I got under with a light and discovered the muffler is not attached to the pipe coming from the catalytic converter, now another thing to fix. I wondered how fluid got into the muffler and then dripped or was there a leak somewhere that was dropping fluid on the exhaust pipe and it was just running down to the lowest point and dripping. I've got a radiator pressure tester on its way from Amazon to see it myself. It was hard to check the engine running because I had to keep my foot on the gas or it would die. I did see wetness on top of the passenger side exhaust manual but didn't see a leak with the heater hoses there. In fact, those hoses were cool to touch when I would expect them to be hot. I've been trying to find a diagram that shows the complete routing of all coolant in this engine. There has to be some bypass pipe or some other crap I can't see that is dropping coolant on the pipe. Any thoughts or suggestions on how to proceed? I'm getting ready to read the codes so I can figure out the idle issue but in the meantime, this was on my mind. Thanks for helping.

 

[Bully Bob]

Hi Jon..,  

My "guess" is the heater core has developed a leak. Easy to change out BUT.., 

usually hard to get to due to all the stuff that has to be removed.

The press. test will prove/disprove that.

You could check the pass. side floorboard for dampness.

BTW.., did you ever test to see if the heater worked...?

Is the pipe touching the muffler or is there a large space between them..?

At some point, you will likely have to pull the spark plugs to get a "read" as to 

the engines condition.

 

[JonD]

The pipe is just sitting in the muffler loose. Thankfully it's not falling out but exhaust is leaking and getting into the cab so it either needs to get welded or replaced. I'll check the floorboard tomorrow but I didn't see it wet today when I was in there working on the radio. When I did the back flush I had the heater on and the garden hose was attached to the heater hose. I seem to remember the cab getting warm but right now it's in the 90s anyhow.

 

[Bully Bob]

Reason for asking about muffler is; worst case scenario.., a leaking head gasket allowing coolant

to run into cylinder & pumped out the exhaust. Usually this liquid will have some dark particles

in it.  A leaking intake manifold gasket could **** fluid in-n-out the exhaust as well.

And, the reason for insp. the spark plugs.

While flushing.., it's not likely there will be any heat at the cab heater due to input of cold water.

It's all fixable.  Others will chime in as to your codes. 

These things just take some time to nail down..., stick with it... :-B   

 

[JonD]

Thanks for the advice. The coolant that was dripping was nice and clear except for the slight yellow tint but looked totally normal which is why it was so puzzling. I get the pressure tester today and hopefully have time to check this weekend. I'm curious about the prospect of a blown heater core. It would make sense.

 

[miesk5]

Yo Jon,

Our 96, bought new has its original muffler. It has a "weep" hole for condensation to drain while engine heats up to normal operating temperature.

return the Amazon Tester to save $. Get one from local parts stores in a loan a tool program... refundable deposit for the pressure tester ...

...

Coolant drains to the bottom of the radiator where it flows out thru the lower radiator hose to the water pump inlet. The pump then forces the coolant into the block, where it flows around the cylinders to the back of the block. Passageways cast into the cylinder block (6010) and cylinder heads (6049), which allow coolant to circulate and absorb excess heat so that engine parts are not damaged by excess heat. Within the head(s) is where the coolant reaches its highest temperature, which is why all coolant sensors are near the head(s). In V8 engines, the coolant flows into a crossover journal in the intake manifold before diverging; in straight 6 engines, it diverges from the head either thru the t'stat or into the heater outlet. In either case, this is generally where its temperature is detected by both the sensor for the gauge & by the engine coolant temperature (ECT) sensor for the PCM (EEC).

Some V8 engines also have a bypass hose which allows coolant to return directly to the water pump. There also is a small circuit to the throttle body for de-icing, which typically returns to the radiator upper tank.

Coolant Line From Radiator to Throttle Body; "...Top hose goes to the filler neck, bottom is the coolant source from the metal fitting that screws into the intake manifold (look where the heater hose and ECT sensor go, there's a 3/8-inch ****** on it)..." Source: by SigEpBlue (Steve)

Coolant Line From Radiator to Throttle Body; "I was just in the dealership yesterday and had them order me one as mine is old and looking tired. They said they can still get it and there is a 20" and 24" mounting tab version. My 90 is the 20". Figured I had better grab one before they disappear and I have to fab my own (cheaper, but I want the factory part). The part number for the coolant line that runs on the radiator is F2TZ8555B (20") and runs about $61 bucks. Got lucky with the water outlet/fitting that comes out of the lower intake manifold that goes to the the heater core and has a port for a temp sensor and line for the coolant into the TB as they still can get this as well and I replaced a leaky one last fall. Pricey for sure, but you pay for stock old stuff I guess." 20" would be a 2 core radiator,

24" would be for a 1 core radiator.

Source: by mbastianel in a 90 Bronco

Coolant Line From Radiator to Throttle Body Fabrication & Installation pics in a 96 :...Here's the photos of the Gates transmission cooler line I used. I also used Oetiker stainless smooth inside crimp clamps. I think they were 21/32" diameter = 16mm. Which is what the 162 mark on them is for....16.2mm. In the photo it looks like its close to the alternator pulley. But its not. 2D photo in a 3D world. /emoticons/[email protected] 2x" width="20" height="20" /> It just runs across the top of the radiator and makes a loop over by the fill neck. The last photo is the short one from the water outlet on the intake to the bottom of the throttle body. Not very expensive either. I think $8 worth of hose. Its pretty high temp stuff...and good to 400psi. My cooling system doesn't quite get to 400 psi..."

Source: by 3speed at http://www.supermotors.net/registry/22641/74821

ECT = engine cooling temp sensor which threads into the "octagonal" tree shaped tube that's threaded into the lower intake manifold and has a small TB cooling tube and hose AND another metal tube/hose threaded into the side which goes to the heater core inlet IIRC.

https://s3.amazonaws.com/2cp-images/question_images/1778/large.JPG

http://www.supermotors.net/getfile/782138/fullsize/what-is-this-2.jpg

This "octagonal" tree shaped tube is available at RockAuto Mobile Catalog

1990 FORD BRONCO 5.8L V8 MOTORCRAFT KT81

http://www.rockauto.com/info/48/E8TZ18B402C-BAC.jpg

{#E8TZ18B402C} HVAC Heater Pipe Tube to manifold

1992 FORD BRONCO 5.8L V8 : for example

Heat & Air Conditioning : Heater Hose / Pipe

MOTORCRAFT KT81 Click for more information about this part

{#E8TZ18B402C} HVAC Heater Pipe, Tube to manifold $48.79

..

Coolant that exits the t'stat flows thru the upper radiator hose into the top of the radiator & thru the core where heat is radiated into the airstream. The cool (lower) radiator tank may contain the upstream fluid cooler for the automatic transmission, and the lower radiator hose may contain an orifice which diverts some coolant to the engine oil cooler if equipped.

Coolant recovery reservoir, which holds surplus coolant. When the system is hot and coolant expands, coolant goes into coolant recovery reservoir. When the vehicle cools, the system draws coolant back into the radiator, eliminating the need for frequent topping-off of the cooling system. The coolant recovery reservoir eliminates the loss of coolant through an overflow tube.

Pressure-vacuum radiator cap, which allows coolant to escape to coolant recovery reservoir when it expands so system pressure does not build, possibly bursting a hose or radiator tube. The radiator cap allows coolant to be drawn back in from coolant recovery reservoir when system cools, refilling system and preventing hoses from collapsing from a partial vacuum in system. The pressure-vacuum radiator cap also maintains 90kPa (13 psi) pressure in the cooling system. Pressurizing the cooling system raises the boiling temperature of the coolant allowing more efficient higher engine temperatures and reducing the risk of boiling over when driving at high altitudes.

Engine cooling fan, which draws air through the radiator to help cooling at low speeds or when the vehicle is not moving. The system is designed so that air forced through the radiator by the forward motion of the vehicle is sufficient at driving speeds.

Fan clutch (8A616), which decreases engine power needed to drive fan by allowing fan to free-wheel when engine is cold or when vehicle motion forces air through the radiator. The fan clutch has a thermostatic control so that it drives the fan when the engine is hot and air flow from the vehicle's motion is insufficient.

Drive belt (8620), which drives the water pump, fan and other accessories off of engine crankshaft (6303). Refer to Section 03-05 for more information on drive belt.

Engine transmission fluid cooler (7A095). On vehicles with automatic transmissions, a provision is made for cooling the transmission oil by circulating running it through a cooler in the radiator.

The lower radiator hose flows TOWARD the engine.

The upper hose flows AWAY from the engine.

The heater hose connected to the intake manifold or t-stat outlet flows AWAY from the engine.

The heater hose connected to the water pump flows TO the pump.

The little bypass hose on V8s flows TO the pump.

The metal line on the radiator flows TO the radiator.

Hot coolant flows OUT of the head or intake manifold. By Ford via Steve with modifications by me.

...

CHECK THERMOSTAT OPERATION

Allow engine to run for 10 minutes.

Feel the inlet and outlet heater water hose and the underside of the upper radiator hose.

Are the upper radiator hose and heater water hoses cold?

Yes REPLACE thermostat.

...

Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19

http://broncozone.com/topic/14269-code-reader/?pid=74587&mode=threaded

Some basics;

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.

Run it around to heat the engine up and shift thru all gears including Reverse.

Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual & release clutch.

Then turn off engine, all accessories/lights (close driver's door) , etc.

Do KOEO test First

Post Code(s) here according to:

KOEO

&

KOER

GL!

 

[JonD]

I meant to respond sooner. I see the weep hole for the muffler but this fluid was coming from the pipe inlet or above. That how I discovered the pipe wasn't attached when I reached up to feel for water and the muffler moved back and the pipe didn't. Got the pressure gauge yesterday, I wanted one anyhow so I'm not sending back. It was only $40 and had great reviews. More to follow when I get back to work on it. Had military work today so one less day to play with it.

 

[Bully Bob]

Thanks for the come-back..!   Rare these days.

We're all curious what you find & ready to help as needed.

--------------- Thanks for your service...! ---------

 

[JonD]

Thank you. It got worse in the diagnosis department when I pressurized the system. At first the drips were just from some loose clamps. Easily fixed. Then suddenly I notice the more the pressure was applied that fluid was coming out of the throttle body opening. I was hoping it was just the throttle body cracked or something but alas it was not. Took the body off, ran water through the cooling line and no leaks. Pressurized again and you could hear it gurgling out of the upper intake throat. Not good. Trying to get upper intake off but ran into that stupid T-40 bolt that's nearly impossible to get to. Read through the forums and found some helpful advice about using a 1/4" socket with long extension to get to it. Just went to harbor freight and bought what I needed. I'll let you know more later. I'm hoping it doesn't get worse that a leaking intake gasket but suspect it could be one of the head gaskets. Fingers crossed I don't need to dig in too deep. I already have a frozen rear driveshaft spindle to get unstuck, I don't want more. I really don't mind though. I did four years of auto shop back at Edsel Ford High School in Dearborn, MI back in the mid 80's so I'm well versed on ford small block motors. Built up a very nice 351C back in 85 for a year of engine rebuilding. The only thing new to me is the EFI and the lack of a carborator. The rest looks very familiar. I just lack all the tools I used to have back in those days.

 

[Bully Bob]

You likely already know this but for others listening,  & depending on the mileage

of the eng. .., it's no biggie to pull the heads.., seeing as how the intake is already off.

Head gaskets are always a clue. Cleaning up the heads is always a good feeling.

If there's bu-ku miles on the eng. a valve job may destroy the lower end.

Looks like you've found the source of water in the exhaust.

Actually sounds like a fun project... [-o<

 

[JonD]

Upper intake off and fluid is coming up the third intake from front for sure. Came right up under pressure. Weird thing is the last intake, closest to firewall, also appears like it had water because all the other intake were black and oily where #3 was a lighter color and so was the last one. Everything I tried could not get fluid to come up. I even plugged #3 and shoved a rage way down the last one and it still came out bone drive after a pressure test. Anyhow, off to auto parts store to buy a fuel rail disconnect tool so I can get the intake off and see what it looks like from there. Still could be a bad intake gasket on that side or even cracked but most likely the head. I'll probably just do both heads if it comes to that. The odometer only goes up to 99,999 and this one reads 27,000. The guy I bought it from said 227,000 but I'm really doubting that based on how well everything looks gasket and wear wise. It's possible but I'd say it looks like 127,000 based on visual inspection.

 

[JonD]

Ok. I got the intake off and oh what a milky mess. Obviously I'm going to need to perform an oil system flush to get everything clear of the coolant. I broke off the first bolt which is pictured. I took a picture of the cylinder port that was pushing up coolant. No sign in that other one I was concerned about. Took off the rocker arm cover and once again another milky mess. I'm having a bugger of a time getting that bolt off that hold the bypass pipe and bracket. Though everything was metric but apparently this one is a 9/16" and only seems to accept my 12 point wrench and not my 12 point socket. With the wrench I'm not able to get the leverage and I'm afraid the bolt head is probably stripped out. I've soaked it in JB but could use some suggestions. Next time I get free I'll get that head off assuming I can get that bolt off along with all the other exhaust manifold bolts. My experience has always been that these bolts are the biggest pain in the butt to get off. Hopefully I can drill out that broken bolt and then get it rethreaded.

 

[JonD]

Any way to test if the coolant was just leaking from a blown intake gasket vs head gasket? I don't want to break it down any more if I've already found the culprit. Hard to do a pressure test with intake removed. Lol

 

[Bully Bob]

Ya.., hindsight is 20/20 ..., A compression test, & plug insp. is always a good place to start.

However.., with everything clear, & the sp. plugs removed.., I think you could still do a compression test.

1 or more weak cyl.  would be a clue. Although, a weak cyl. could be due to a couple diff. failures.

Valve, gasket, rings to name a few.

Problem is.., water-n-oil would likely flow all over the place.

You'd have to disable waterpump & pull the dizzy to stop oil pump.

I've never done this soooo.., proceed with caution.  (    :-B   [-o<

 

[JonD]

I thought about putting a hose into the left head intake and put water in looking for water coming out of the intake ports.

 

[Bully Bob]

I think (W/O being under press.) there's too many other BIG places for water to circulate out to get your results.

 

[JonD]

Yeah, me too. I took out the plugs and it's obvious at least two on that side weren't working right. One of the plugs was a completely different type so who knows. Out of the four only one looked normal.

 

[JonD]

Got the exhaust bolts off finally and ended up with a cracked exhaust manifold. Could have been there already but very obvious now after I tried to pry to the side to reach the head bolts. Planned to replace them anyhow, any suggestions? Took out the spark plugs and only two showed signed of actually being used. The one was wet from the cylinder I knew was leaking. The other wasn't even the same type plug. They were all bosch platinum but the one had two instead of one metal things. Forgot what they're called. I've included the pictures of the whole top and just the one part that is obviously the issue. Not really sure why I have rust in the first cylinder where the second is the one with issues but no rust there. Moving on to take other head off and take to local machine shop to be checked and resurfaced.

 

[Bully Bob]

GOOD job...!! 

Amazing it ran at all.  Did you clean that piston top...?

Exh. manifolds snap quite often. Lotta hot-n-cold.

Not sure how thick your pocketbook is but this could get a bit more expensive..... :-B