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Recent 340 Rebuilt - Coolant creating thick green film

Titan1969

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Since the oil is not contaminated, it might not be oil/coolant problem, it could be exhsust/coolant problem.

If there was a hairline crack(very small one) in on of the heads, between an exhaust and coolant chamber wall, hot exhaust could find its way into the coolant side (and froth it up) but not the other way around.

if this is the case, wouldnt the coolant eventually calm down and look normal? it stays in a pasty state even 24 hours later, guessing something is mixing with it and permanently changing its properties.
 

Mopar Nut

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no, havent driven the car anywhere due to the coolant issue. I could find a local shop to test.
You can borrow a coolant pressure tester at your local auto parts store. Most places offer them as a loaner tool for free and it’s really easy to do it yourself.
 

moparleo

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It is good that the valve cover came out without issues there, but did you pull the spark plugs yet ? I would still not run the engine anymore until you eliminate any water in the pan. Idea... Drain the oil, pull the filter. That will verify if water got into the pan and into the oil pump, bearings... Just an FYI ASE certifications are for each automotive area just like DR. degrees. for neurology, podiatry, orthopedic etc..., etc... specialties. ASE Does not mean engine expert unless he has a current cert in that area and he really only has to pass a test. A Master ASE is more significant. Very familiar with the program and the BAR. I retired as a Store manager for a major tire manufacturer in California. I required all my tech to have at least 2 ASE certs to work Brakes and Suspension. The tune up tech had certs in those areas.
If you find water/foam in the filter or pan and ran the engine for hours, you can be assured there will be bearing damage at a minimum
 

Titan1969

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***UPDATE****
thx in advance for any advice/feedback on my issue

These are the steps I followed in the order I followed them...
1) Engine intact nothing removed/apart
2) Pressure tested cooling system, held 16lbs for over an hour
3) With cooling system under pressure I cranked the motor ( coil unplugged) looking to see if the pressure gauge bounced/moved. Nothing changed. I had assumed if a head gasket issue, this might show up on the coolant gauge.
4) with cooling system under pressure, removed spark plugs, watching gauge each time, so see if pressure bleed off. nothing changed.
5) Plugs all good, light tan/brown on tips
6) Removed oil filter, keeping contents in the filter until out from under the car. Then poured contents in bucket looking for coolant, foam, film, sludge....but nothing.

While the above I believe is all good, its no closer to telling me whats contaminated the cooling system.

I believe Im down too...
1) Cooling system was contaminated from
a)new rad
b) uncleaned coolant passages after rebuild
c) orignal heater core had contamination ( had not been cycled for 20+ years and wasn't cleaned out prior to engine install)
4) resto shop mixing two different coolants
5) someone playing a prank
6) crack in block only weeping oil into coolant when engine running / under oil pressure
7) other

Next steps...
1) Run motor tomorrow, one more time with water flushing out system AGAIN
2) Drain again
3) add Blue Devil Coolant Flush , add water, run motor 10 minutes
4) drain
5) refill with water, go for a drive
6) pray to the motor gods
 

fasjac

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Everything is sounding good! There’s really not a lot to do now. I agree with the process moving forward. Keep us posted and good luck.
 

Titan1969

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Update 1/30/21

Its been a few weeks since I updated this thread as I have installed a new carb, fixed numerous wiring issues, so I could get back to dealing with the coolant contamination issue.
I have drained and filled the cooling system again with water ( not a true flush as in CA as we cannot just run a hose through the system on the ground where I live).

I refilled with water and while this is clearing up the cooling system slowly, Im not sure I have determined if a I have a problem or just a issue from the rebuild ( see earlier in this thread ).

So today took Cuda for a quick drive and back and then as I drained the water out, yet again still some green slime coming out but less and less contaminants each time i drain it, I again checked the oil dipstick...no issue just clean oil and level is normal.

BUT.......I then noticed this sorta of weep hole in the intake manifold was wet.

I had not seen this before and I definitely had not spilled anything on the motor.
So I stuck a small screwdriver in the hole and it was OIL

1) Can anyone tell me the purpose of this hole/divit in the intake?
2) Could this be a sign of a potential cracked intake or manifold gasket failure?
3) Or does this hole mean nothing and its just oil left from someone elses spillage month agao during the engine install?

Coolant Issue - Intake Weep Hole - Oil.jpg
 

fasjac

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I’m not accessible to my book but, I believe it may be a guide hole for throttle return bracket. I can look tomorrow. It definitely doesn’t go all the way through the intake right?
 

Titan1969

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No the hole doesn't seem to go all the way and thanks fir the assistance.

it could make sense if this divet is for a return bracket.

The one on the car I thought was original but it does tend to swivel on the the single bolt holding it on the engine if I bump it, which does not seem right to me...should be fixed unable to move IMO.
 

Chryco Psycho

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I didn't read everything through but it could be a leaking trans cooler inside the rad .
you could disconnect the trans cooler or run an external cooler & see if the problem continues .
 

Titan1969

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I wanted to tie this story off.
At this point I can find nothing wrong with the motor, continues to hold 80lbs cold pressure and 25lbs warmed up in gear and no oil is entering the cooling system, the oil level never has dropped = good news.

I ran de greasing agent from Red Devil and interestingly the Red Devil did not break down the green pudding, seems impervious to the degreaser, though when the motor is warm the pudding is pooling at top of rad so Im skimming it off through the filler neck...slowly but surely.

Meanwhile through several drain and refill with water of the cooling system, it is improving overall.

I never had any overheating issues, just fyi
 
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