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Hi i got 03 peterbilt with cat c15 6nz serial number had oil…

Hi i got 03 peterbilt...
Hi i got 03 peterbilt with cat c15 6nz serial number had oil in coolant changed water pump and thermostat by than we saw oil cooler is dirty so i changed that to after 2 weeks i see again little oil in coolant need help to know what else could be the reason, oil cooler was installed after market purchased from peterbilt dealer
also i see on other side air comprassor is sweating with little oil
thanks
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Answered in 9 minutes by:
10/13/2012
Technician: Cat Man, Cat Engine Expert replied 9 years ago
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
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Hi. Thanks for using JA! I will try and help you out.

The most common item that causes oil to enter the cooling system is the oil cooler. It is possible for either the head gasket to cause it or a cracked head. But to be honest, it is very rare for the head or head gasket to do this. On some rare occasions I have seen a small hole in the liner cause it as well but when that happens there are usually a little coolant in the oil.

I have not ever seen an engine air compressor do this on a C15.

You mentioned the oil cooler was an aftermarket. I have seen both after market oil coolers and reman Cat oil coolers that are new leak after they were installed. I would recommend having the oil cooler removed and tested. You may have gotten a bad one out if the box. I would definitely have the oil cooler tested or replaced just to make sure before removing the head. If the not cooler does not fix the problem, the. It is time to remove it.

Please reply back if you need more help or have more questions.
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Technician: Cat Man, Cat Engine Expert replied 9 years ago
Hey Yoad. I just wanted to see how things are going. Please let me know if you need more help ro have more questions.
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
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Customer reply replied 9 years ago
I did ask If you can tell me how to check the oil collet my self
Technician: Cat Man, Cat Engine Expert replied 9 years ago

Hi Yoad.

 

In order to test the oil cooler it must be removed and pressure tested. To pressure test you would need to have the adapters to connect to the oil side of the cooler and attach an air hose. Then you submerge the oil cooler in water. If it is bad you will see air bubbles coming out of the ends of the cooler.

 

Let me know if you need more help.

Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
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Customer reply replied 9 years ago

is it could be transmission cooler leaks oil to coolant system ?

Technician: Cat Man, Cat Engine Expert replied 9 years ago
Hi Yoad. Yes. It is very possible if your truck has a transmission cooler that the oil you are seeing is trans oil. I have seen this before. You can also have the trans cooler pressure tested to verify.

Let me know if you need more help.
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