Engine block not heating up.

[pipeline010]

EDIT: ORIGINAL POST BELOW

low coolant/antifreeze level allowed flash rust to form along top of radiator which gummed up coolant lines. This, in turn, jammed up the thermostat which was stuck open, preventing engine reaching optimal temperature in cold temps, especially when driving over 30mph.

Solution: [total cost ~$40-50]
Drained Radiator and filled with Firestone Cleaning Solution. [eliminated rust]

Reverse flushed heat inlet hose using kit and water hose. [removed rusty sludge from line]

Replaced Thermostat and old burred housing.

original post below
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Hey guys, thanks for any and all replies.

Got real cold outside this week up here and my truck wasn't getting up to temperature. It's been a little flaky by temp the last few months, definitely responding to whatever the outside temp was. Shoulda checked the rad fluid sooner....

So I open up the radiator and see this -

https://classicbroncos.com/forums/attachment.php?attachmentid=370253&d=1435556463

Quick search, looks like gummed up rusty paste. Undeterred, I end up having to pour about half a gallon of 50/50 to refill radiator to the top.

Let her start to warm up in the driveway and after about 20 min she still won't break about 130. This is confirmed by crappy heat blow, she's always blown hotter than a reactor.

So I'm assuming I've gummed up something along the system with letting the fluid drop so low. Where, exactly, should I be pulling and flushing? Thanks guys,

 

[blubuckaroo]

Your thermostat probably needs changing.
There should be a petcock or drain plug on the lower driver's side of the radiator.
Drain it and flush it.
With the drain still open, keep it topped off with the engine running and the heater valve open. I use a garden hose running at a trickle. Flush until it runs clear, then let it drain completely.
Refill with coolant.

That rust came from somewhere. Probably the steel freeze plugs. Most likely your coolant got old and corrosive.

 

[pipeline010]

OK thanks blu. Supposed to hit 51 outside on Monday, so I'll try then.

Sorry for ignorance, but this should flush the cooling system entirely ya, not just the rad?

 

[75MIKE]

Follow the directions on the Prestone flush kit, it works very well.

By the way, don't flush the rusty coolant on any concrete that you don't want rust colored for the next 5 years.

 

[blubuckaroo]

OK thanks blu. Supposed to hit 51 outside on Monday, so I'll try then.

Sorry for ignorance, but this should flush the cooling system entirely ya, not just the rad?

It takes a while, but doing it like this will flush everything.

 

[DirtDonk]

You need to either leave the heater TEMP control knob pulled all the way out (valve open) to clean the heater core, or flush the heater separately.
You might still end up doing both, just to be sure you've gotten it all out of the heater core, but you can do it either way.

Paul

 

[pipeline010]

Simple problems require massively annoying solutions....

So in the process of draining my radiator the entire drain housing came off the radiator as un torqued it.

Pic below. Any suggestions?

https://drive.google.com/file/d/1oLrnHKLaXkRiuxMpGisn3D--eZGUi-c3/view?usp=drivesdk

 

[blubuckaroo]

I'm not familiar with that tube on the drain valve. Mine have always had the drain valve threaded directly into the threaded bung hole on the radiator.
If there is a threaded bung hole on the radiator, you should be able to thread in a 1/4" brass pipe plug or petcock.
A good auto parts store should have it.

 

[pipeline010]

No threads on interior of radiator wall drain. All smooth.

 

[blubuckaroo]

So, the tube to the petcock was soldered directly to the radiator tank?

 

[rmk57]

I would say to the job right your going to have to take the radiator out and the petcock re-soldered. While your at it get the radiator boiled at a rad shop.

Plan B would be to try and JB- weld it back in. Iv'e repaired leaking radiators that way but they have never lasted more a few months.

 

[DirtDonk]

I'm not familiar with that tube on the drain valve.

Never seen one either. Maybe it was a common bit on the factory radiators up to a certain year?

Mine have always had the drain valve threaded directly into the threaded bung hole on the radiator.
If there is a threaded bung hole on the radiator, you should be able to thread in a 1/4" brass pipe plug or petcock.

That's the threaded bung in the pic. The big hex piece right there at the petcock body. It pulled out of the radiator itself.

Were you trying to turn just the valve T-handle Pipeline? Or were you trying to remove the entire valve body/block/thingy because the T-handle was stuck?
Or did you put a wrench on the big hex piece instead?

Paul

 

[pipeline010]

I was just turning the release valve on the petcock. It was a bit leaky at the base, gave it a tug and it literally slid right out.

I solved that problem (for now). Plummer fitting, basically a rubber stopper with an embedded nut. Put the stopper through, screwed into the nut, and the rubber expands to fill the space on the rear end. Used a blue permatex around the screw before putting it on. So it's holding, for now.

But the problem still exists. I backwashed my heating system, flushed it, used that Prestone kit for 3 days as it says on the bottle. Temp still won't break 140/150. One thing I haven't done yet is to pull and change thermostat?

 

[EPB72]

So in your first pic that looks GM to me plastic rad tank?? if so that is the bulk head fitting for the drain ,,the inner portion is rusted/rotted away i'd be looking for a new radiator,,,continue to flush replace radiator at end of flushing when u think its clean enough ,,t stat replace as well I wouldn't be surprised heater core as well,,,if gm that 150k dexcool service interval was a joke

 

[pipeline010]

The first pic is actually a hijack. I didn't take that, just found it online and the red sludge matched mine. My rad is metal, looks like aluminum.

 

[DirtDonk]

Was the coolant as-delievered when you bought the Bronco? If so maybe the PO installed an aluminum radiator and thought they'd use Dex-KILL because of that?
Could happen, seen some do just that.
But any coolant will eventually turn to similar gunk if not changed, or if it's mixing with engine oil, or perhaps combustion gasses.

I hate that stuff. It's what my Buick's radiator has looked like for several years now. Most of which were spent with water instead of anti-freeze while I tried multiple times to flush it out. Still looks that way, so I'm going to try to use something stronger the next time I flush.

Good luck!

Paul

 

[blubuckaroo]

The first pic is actually a hijack. I didn't take that, just found it online and the red sludge matched mine. My rad is metal, looks like aluminum.

If your radiator is aluminum, the drain fitting may have been epoxied in. A radiator shop should be able to repair it. You might as well have the radiator flushed properly at the same time.