Ok still chasing a cooling problem. Was looking at the coolant color today and it is dark greenish almost murky. I should have about 75/25 mixture now. The engine was just replaced and right when i got the car back i started having these issues.

Is there any significance to the color of the coolant (i dont mean orange vs green). I have heard of a coolant fluid tester and thought about trying that.

I even poured some fresh coolant into a dark container to make sure i wasnt crazy. With half and half water its definately lighter in color and more transparent than what i see in my rad.

I know its possible to leak coolant into the oil, but is the opposite true?

 

I think what your might seeing is a leaking trans cooler line...if the line inside of the radiator is leaking it will leak trans fluid into the radiator along with the coolant.Might want to check the trans fluid level and condition.You will need to remove the radiator and repair/replace it.

 

I thought the trans cooler was separate from the radiator. I mean I didnt think it was possible to leak into the radiator because my trans cooler is mounted to the outside of the a/c condensor

 

Some of the factory trans coolers are built into the radiator.

 

Its possibly you just got some sediment from the rebuild.Have you flushed it and installed fresh antifreeze? Your supposed to clean the engine block with soapy water to get out all the left over debris after you get the block from hot tanking..its possible they didnt do that during the rebuild?

 

The engine was rebuilt and purchased from a online warehouse. I imagine it was probably hot tanked and cleaned. Not sure.

But i tested the coolant with one of those tubes with the 5 colored ***** in it. I tested straight antifreeze and all the ***** float. Tested 50/50 water to antifreeze and got 4 ***** floating. Then i tested mine and had 2 floating. So at least i know the boiling point is ok.

But i was thinking a flush might be a good idea. I drained some fluid from the rad a few days ago and dont remember seeing any sediment in it after draining the container.

Oh, and to make it more frustrating, I was running 230 today on the highway (with my airdam) in 95* weather. What is going on here?!

Thought about leaky head gasket, but I have absolutely NO coolant leaks.

 

flush it away first and see.
if same thing happens,
im sorry to say but your guess might be right.. the oil could
be leaking into water passage.

it probably explains why your engine can overheat because
engine oil won't conduct heat as much as coolant or whatever..

just my guess though.. good luck!

 

I think the other guy may be right, and your getting ATF into your coolant system, check your engine oil level,trans ect (eliminate things) no matter what anyone tells you about diagnosis always start with the basics

 

Yeah..I agree but you also said you had a trans cooler mounted to the front of the radiator ,so if its not flowing through the radiator it will rule that out.A leaky intake manifold gasket could also be something to consider?

 

He never said he had an Auxillary Trans cooler and about 85-90% of them are built into the radiator therefore......

 

Nope it is auxillary and all lines to trans are separate. I checked trans fluid and all was well. Checked engine oil and it looked ok too. But Its hard to tell by looking at the dipstick if its contaminated.

How could oil be getting into the coolant? Via the intake manifold gasket?? What other ways can oil get in?

 

Holy crap!! I just siphoned some coolant from my overflow tank to look at it in the light. Dark and murky as pea green soup with sediment at the bottom and an oily (hydrophobic) liquid on top forming little circles.

Well there are a few explanations:
1) when they installed the 350, they used the same coolant from my 200k mi 305 which had lots of sediment in it and was darker.

2) They didnt fully clean the engine before installing it and this is just engine residue from honing etc.

3) they miffed on the install and I have a leaky intake gasket

4) the engine builder miffed on the honing/boring and I have a leaky coolant passage somewhere. But these engines come with a 7yr warranty and are supposed to be well built.

Hopefully its 1 or 2 and I can just flush and fill and be done with it. But this is rediculous any way you cut it and someone (not me this time) is an idiot.