Dirty Coolant on a New Build

[mj2619]

Little backstory.

• Had a shop do a restoration over the past year.
• New engine, transmission, radiator, transmission cooler, a/c, the works.
• Engine is a brand new Blueprint 302.
• The radiator is a new Tom's off-road aluminum .
• Picked it up last week, drives great, sans some QC issues.
• Runs 210-215 but no issues driving and does not spike above that range.
• I noticed the coolant reservoir was turning a dark green. I drained and refilled the reservoir 50/50 bright green.
• I have drained and refilled the reservoir 3 times as it keeps turning dark.
• In the 3rd image you can see it looks like something is separating from the coolant (oil?, transmission fluid?, it's sitting below not floating?)
• First image is under the radiator cap, it looks like rust residue?
• 3rd image is where the installer hit the transmission cooler.
• Tomorrow I am doing a complete flush to see if that remedies it.

Any suggestions or advice?

Thank you!

 

[serial car restorer]

Did you replace the heater core?

 

[mj2619]

Did you replace the heater core?

Hey! I had the Classic Auto Air kit installed so everything was replaced.

 

[73azbronco]

any coolant missing? do a pressure leak test of cooling system, tool at autozone.

 

[AZ73]

Blueprint dyno's their engines using water, not coolant. They never get all the water out. So how long was the engine sitting before your shop installed it? Might be light rust on the inside of the block. A flush should tell you more. Ask me how I know

 

[mj2619]

Blueprint dyno's their engines using water, not coolant. They never get all the water out. So how long was the engine sitting before your shop installed it? Might be light rust on the inside of the block. A flush should tell you more. Ask me how I know

14 months at least.

 

[AZ73]

14 months at least.

Plenty of time for the jackets to rust.

 

[mj2619]

Plenty of time for the jackets to rust.

- I am having the system flushed tomorrow. Any other recommendations? Long term problem?

 

[serial car restorer]

Long term problem?

I wouldn't think so, no.

 

[73azbronco]

no, no issue, steel or brass freeze plug? Might indicate not completely bled out

 

[AZ73]

- I am having the system flushed tomorrow. Any other recommendations? Long term problem?

Shouldn't be, although there MAY be some deterioration to the water pump impeller. But it's pretty stout and 14 months isn't that long. A good flush, and refill with quality coolant and you should be good to go. Assuming it's what I suspect it is.

 

[Johnnyb]

After a similar rebuild, new everything, I drained my radiator after a couple hundred miles and found dark sludgy coolant. I also found that the sacrificial anode was highly deteriorated.
Pressure tested it, no leaks.
Flushed the system out, filled it back up and reinstalled it without the sacrificial anode and it hasn't darkened since.
I know it seems wonky but what if they put the wrong metal in the sacrificial anode? I'm not a chemist so I don't know what that might be, but the signs clearly point to that being the issue for me.

-JB

 

[mj2619]

Flushed the system twice and looks pretty good so far. Will drive it for a while and do it again. No smoke or leaks which is great. Thank you all for the feedback!

On another note - 220 running hot? I have a radiator with Shroud from Tom's and a transmission cooler. Just seems toasty. Any advice?

 

[Oldtimer]

If you have an IR thermometer, verify actual temp of intake manifold near the sender.

 

[Timmy390]

Flushed the system twice and looks pretty good so far. Will drive it for a while and do it again. No smoke or leaks which is great. Thank you all for the feedback!

On another note - 220 running hot? I have a radiator with Shroud from Tom's and a transmission cooler. Just seems toasty. Any advice?

I run a 195 stat and it runs 210 95% of the time.....but when air temp is hot i.e summer and I'm towing my utility trailer around it can hit 220....my electric fan kicks on high at 220. It cools right off......I should also mention I use a mechanical gauge.

So 220 is not hot per say as hot is a relative term. A/C running ? Sitting at idle? On the highway?

As to the coolant being dirty......mine did the same with junk yard heads.......it's rust........

Tim

 

[ntsqd]

To get a truly accurate reading with an IR temp gun you'll want a small spot of flat black paint where you want to take the reading.

 

[Johnnyb]

EB OEM type gauges are notoriously inaccurate.

 

[Boss Hugg]

I’m doing a flush as I type. Water pump went bad, so I’m trying everything right being putting it back on the road. For the past 4-5 years when I flush, fill with yellow coolant, within 1000 miles, my coolant is VERY rusty. I’m going to try some water wetter or similar this time.

Current problem that brings me here: stock explorer engender units and own bronco temp gauge. Does anyone know the difference in resistance ranges as they relate to what temps? I’ve always observed 170-180 on my gauge with 192 stat. Sitting here flushing cold water thru it, it’s reading just above the 120 mark. So I’m thinking I need to put an early ford sender in it to get “more accurate” readings.

Attached pic is what I get out of the stat housing when the gauge is showing 170. Water hose attached at sufficient volume to keep the radiator full on the inlet to the radiator.

 

[DirtDonk]

Why do you use yellow fluid? Should you just be using Green?
And yes, the two sending units are wildly different. You have to use a Bronco sending unit for the Bronco gauge. The only reason to use an explorer sending unit would be for an Explorer computer to work. Assuming that they need a coolant temp sensor that is.