oil in coolant?

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oil in coolant?

Post by 101son » Wed Jan 17, 2018 5:54 pm

How can I tell if its just a dirty engine or oil in coolant? Just drained the radiator to reseal a thermostat housing bolt and my new coolant is darker than it should be especially with only having 20 miles on it. is there a sure way to tell?


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Re: oil in coolant?

Post by Joe Gopan » Thu Jan 18, 2018 3:56 am

This is common in well used Jeeps.
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Re: oil in coolant?

Post by 101son » Thu Jan 18, 2018 9:02 am

Thanks, I will check it out. How would that happen with such low miles on the engine?

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Re: oil in coolant?

Post by Joe Gopan » Thu Jan 18, 2018 2:14 pm

Did you retorque the head after the first warm up?
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Re: oil in coolant?

Post by 101son » Thu Jan 18, 2018 2:24 pm

Yes the engine has 20 miles and I did re torque the head after warm up.

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Re: oil in coolant?

Post by fernando mendes » Fri Jan 19, 2018 4:30 am

bantamj wrote:
Wed Jan 17, 2018 10:14 pm
Put some coolant in a plastic bottle and let it sit for a while.
Oil will raise to the top and water settle down.
Empty the bottle and if oil residue is found on the bottle wall you know it is present in coolant.
coolant 1.jpgcoolant 2.jpg
Oil residu in coolant is a sign of blown head gasket.
The exhaust gasses entering the water jacket and the unburned oil is poluting the coolant.
This video show how to determine if exhaust gasses are entering the water jacket.
When the rad is filled to the top air bubbles can be seen escaping via the rad neck.
The video shows a severe case, in your case the air bubbles might be much smaller and less intensive.
https://www.youtube.com/watch?v=F2GCNl_ ... e=youtu.be
Another sign of coolant polution by blowby is the rusty color of the coolant like seen in both the pic's and video.

Good luck,
Luc
Until which temperature(160F or 180F).Do you have a test to know if fuel is present in the oil?Thanks.Regard.
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Re: oil in coolant?

Post by Chuck Lutz » Fri Jan 19, 2018 6:17 am

What is the story on the radiator? Could the engine rebuild have taken place because of oil in the coolant and enough oil had remained in the core after it was drained to begin with prior to the rebuild....that this is now what you are finding with HOT coolant now circulating?

How much oil are you finding?
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Re: oil in coolant?

Post by Wolfman » Fri Jan 19, 2018 6:25 am

Good point, Chuck.
I don't know how many times I have seen someone spend a ton of $$$ on a rebuild, only to reinstall the nasty, original radiator.
At this point, probably won't come to a conclusion until the cooling system is flushed and I would use a cooling system flush additive when flushing. Not just water. Plain water may not do the job.
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Re: oil in coolant?

Post by 101son » Fri Jan 19, 2018 6:45 am

I had the radiator boiled and repaired. I will flush the system as mentioned and see what that does. Thanks for the advise.

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Re: oil in coolant?

Post by fernando mendes » Sat Jan 20, 2018 7:40 am

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Posted 11 hours ago (edited)

Uhhhhh....no....that's the coolant system shifting air out and water in, it will also bubble when the thermostat is open and cycling

Another opinion of a Dodge forum friend.
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Re: oil in coolant?

Post by 101son » Sun Jan 21, 2018 6:04 am

Ok, i don't see any oil residue and the brown black sits at the bottom of the bucket. So I think it is rust. I flushed the system about 4 times and the water looks alot better. Ill probably run this coolant until summer and flush it again then. Thanks for all the help.

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Re: oil in coolant?

Post by Wolfman » Sun Jan 21, 2018 6:19 am

Sounds like good news.
Don't know where you are located, but are running anti freeze or just plain water ??
Straight water will form rust pretty quick and give the results you have described.
Anti freeze, even if you don't need it, has rust inhibitors that will stop rust and corrosion formation.
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Re: oil in coolant?

Post by Chuck Lutz » Sun Jan 21, 2018 10:06 am

I believe that when an engine is rebuilt some crud/rust and even some factory casting sand could be dislodged and will only be flushed out with the flow/heat from running the engine. Baking the bare block may break it loose but getting it all OUT is another issue!

Rather than tearing into it, flush the coolant from radiator (or remove it to do a MUCH better job) and the engine and put at least 40 miles on it and recheck when you drain it out again.

If several tries each eliminates more and more crud, that may do it. Watch the temp gauge constantly though.
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Re: oil in coolant?

Post by fernando mendes » Sun Jan 21, 2018 12:22 pm

Hi Fernando, Fuel in oil? I don't understand your question.

Luc

Hi Luc.My 1952 Dodge PU is with probably presence of fuel in crankcase.I ask if you have a good test :idea: to discover if fuel is in the oil.I only know seeing the increased level in the dipstick and its color grey too.Thanks.Regard.
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Re: oil in coolant?

Post by artificer » Sun Jan 21, 2018 1:22 pm

Light grey is an indication of coolant & will be evident in feel when rubbed between fingers.
Rise in level & oil smelling of fuel is an indication of a bad fuel pump diaphragm.
Check the fuel pump output/pressure.
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