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Coolant leak?


dashhho

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While driving home today I stopped to make a quick call on the side of the road. When I stopped I noticed smoke coming from the hood - I looked at my temp gauge and it was normal and then shut the truck off and popped the hood to take a look. The passenger side of the engine bay was covered in a good trothing of coolant. I checked the reservoir and it was bone dry (it had some in there yesterday or the day before for sure). The top coolant hose that connects to the rad was empty but there was some coolant in the rad. The smoke was coming from the coolant dripping onto the cats - that sweet sweet smell.

I drove it to a rad shop 10mins down the road - the guy filled the rad and pressurized the system to 10psi. It held at around 6psi and the guy figured he found the leak near the waterpump but it was hard to tell for sure. I was about 80miles from home - the rad guy figured I could make it so I grabbed a gallon of premix coolant and headed off.

Made it home and it doesn't look like I lost anymore fluid - If I did it was minimal. Temps were okay. The engine bay was pretty dry also - so now I'm confused. I'm now wondering if we mixed antifreezes and its jelling up and plugged the hole? There was yellow coolant in the reservoir when I bought the truck so I assumed that it was safe to use it. From what I read the yellow stuff is okay for my year of truck.

Anyways, the trucks got 220k kms on it. Are these waterpumps an issue? or the hoses etc. Looking for some help on what avenue to go with this. I'll park it and use my other vehicle for now.
 


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cbxer55

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The usual culprit for 4.0's is the plastic thermostat housing. And yeah, when they leak, it gets the passenger side more than the driver's side. Mine did on my 4.0 mustang. I replaced it with a metal unit. The thermostat housing I am talking about is that whole unit that thermostat and the heater hoses attach to. They are a known leak point. Stupid plastic parts.
 

dashhho

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Thanks Cbxer. I'll add it to my parts list. While I have stuff apart I want to do as much as possible. I plan to drive this thing for a long time so I'd hate to keep coming back to things.

Any recommendations for brands on the housing? any metal one is better than plastic I guess..
 

DILLARD000

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Assuming your 2005 B4000 has the V6~4.0L~SOHC.
Ditto on "stupid plastic parts"!
Prime suspect is the plastic ThermoStatHousing, notorious leaker; other plastic Coolant parts could also be cracked+leaking:
* plastic HeaterControlValve
* plastic Tee assembly in the Heater+PCV Coolant loops.
* plastic tanked radiator
Over several years, I've replaced all these in my 2001 V6~4.0L~SOHC due to cracked plastic.
More info at

Hope this helps.
 

DILLARD000

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PS:
There are several brands\vendors for the aluminum ThermoStatHousings; ZabTek, SAS, RockAuto, Amazon, Ebay...
SAS\Simmon's is a single cast body & most expensive; the others are a 2piece body with gasket;
both designs have advantages\disadvanatages, any of the aluminum housings are better than any plastic housing.
Your local parts counter will likely just have the same old junk plastic in stock.
Price difference plastic to aluminum is negligible, just need to be able to wait for delivery of the aluminum.

Recommend doing a full flush of your Coolant system, especially the Radiator & HeaterCore,
then replace all Coolant hoses, the ThermoStat, RadiatorCap, & fresh 50/50 Coolant.
If the CoolantPump + FanClutch + Fan + Belt are original, they're due for replacement also.
 
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cbxer55

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The one that I put on my Mustang is the one piece unit. I prefer it, as it's one less joint to leak. Sometimes, that old adage, You get what you pay for, is relevant. I always prefer not to cheap out on things. Usually if you do, it'll come back to bite you in the nether region.

This is the one I bought. Excellent fit and finish. It's the Simmons.
 
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dashhho

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Thanks Dillard and cbxer. I noticed there are 1 and 2 clip sensor housings so ill have to find which works for my truck
 

cbxer55

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My 2007 Mustang only has one. Thankfully.
 

DILLARD000

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...1 and 2 clip sensor housings
...have to find which works for my truck
Just take a look under the ThrottleBody & you'll see 1 or 2 ClipMounted TempSensors;
older years have two (1 for the ClusterGauge, 1 for the Computer); later years have just one.
In the AluminumHousing, the 2nd unused TempSensor hole can be filled with a pipe plug
Recommend using\reusing the Ford OEM TempSensors; some of the Chinese sensors are junk & burn\short out.
May need to replace the Sensor ORings or just smear a little RTV around the old ORing before reinstall, to get a good seal.

Consider replacing the LeftFront OilPressurized TimingTensioner (both LeftFront & RightRear should be done every 75k~100kMiles)
while you've got the ThermoStatHousing out of the way.
 
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dashhho

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Wow, getting the thermostat housing out with the two clip sensors and all the other junk in the way was.....fun. Why did ford cram so much plastic in such a tight spot when they had the whole engine bay.

It looks like the thermostat housing was the leak but I found some other things;

the idler pulley had some play
Water pump bearing has a tiny bit of slop - it was original so best replace it now (as Dillard suggested).
Radiator starting to go possibly? see pic below

I'm not sure how to test the fan clutch? It was a bitch to get the nut off...I wasn't able to break the nut while adding tension to the belt with the 3/8" drive bar. I ended up having to hammer the nut with a punch on the end of the nut a bunch and finally broke it free.

I almost feel like while I have all this stuff of the front - why not go through the whole top end haha. I do have a P0456 (small evap leak) code that I've never had the will to tackle...
 

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DILLARD000

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From your pics, can't tell if that's a radiator leak or just dirt?
Probably should at least unbolt the radiator at the top, lean it back enough to inspect the front side for debris.
I would just go ahead & pull the entire radiator out to give it a full all around inspection & cleaning.
At 16+ years old, likely to find a crack\leak or two, especially in the plastic tanks; recommend an AllAluminum replacement.

About the FanClutch, have to test that before taking the Coolant system apart.
~ With engine cold & off, Fan should be stiff on clutch & hard to spin by hand.
~ After engine starts\runs for a couple of minutes then off, Fan should spin relatively freely.
~ After engine starts\runs to 180f+ then off, Fan should again be stiff on clutch & hard to spin.
Again at 16+ years old, it's overdue for replacement.
 

dashhho

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Good to know how to test the fan clutch for next time. When I was taking the nut off the fan it was fairly easy to move - I'll replace it anyways.

I'm thumbing around which brand waterpump to get. The Motorcraft one is almost twice as much as the other brands (Gates/AC Delco/GMB). Is it worth the premium?
 

DILLARD000

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Last pump I put in was about 5yrs ago. Oreilly stock. Don't recall brand. I did soak bearing with oil inside &out overnight before I put it in.
 

dashhho

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So I decided to pull the intake off and clean the mess from the leaking thermo housing. I noticed that the area around the PCV was a little oily and it had a bit of play when jiggled. So its off now and one of the plastic retaining tabs in the valve cover has broken - one is left. The on remaining tab still holds it from falling out but the PCV is able to wiggle somewhat. The other end of the hose that connects into the intake looks like the its not sealing fully? I'm not sure what this "part" is called? The two lines run coolant to the PCV.

I was contemplating trying some RTV with the PCV and see how it holds - but the other side of me says to just replace the valve cover while I'm this far. How much more work is it to take off the covers on these SOHC's? Is there anything else worth doing if that is the route to go?

PXL_20210406_212252950.jpgPXL_20210406_220536428.jpgPXL_20210406_220615524.jpgPXL_20210406_220702992.jpg
 

dashhho

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Looking at the intake manifold it's a little oily for my liking - is this normal for this 4.0L engine with ~200k kms? Seems like a decent amount of blowby coming through but I'm no expert.....
The truck doesn't lose any noticable amount of oil between changes. The guy was running full synthetic in it before I bought it.

Edit - Seems normal from my research.

I've been thinking about what's been leaking on the passenger side of the manifold (the passenger valve cover shows a bit of oil creepin on the dirt). My guess right now is that the intake manifold gasket has been leaking - you can see staining on the bottom of the passenger side of it on the pics. If it was the valve cover gasket I'd assume the leak would be much more noticeable.
 
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