Contamination in coolent system

Re you sure it is engine oil? Or is it transmission fluid? Automatic transmission cars usually have a transmission oil cooler in the radiator. These can crack and leak fluid into the cooling system. It will act quite often like engine oil. It will eventually turn blackish in color because the trans fluid will eat away at the rubber hoses in the cooling system, and turn them into jelly.

The oil that is in the cooling system may be Transmission fluid if you have an automatic transmission and the transmission cooler in internal to the radiator. Check your transmission oil for water contamination. If it is contaminated, you will probably have to rebuild the transmission and replace ALL of the transmission lines, and all rubber coolant hoses as the transmission fluid will eat the rubber hoses from the inside.

White smoke is usually a sign that there is a problem with the cooling system. Blue smoke is fuel related.
Have the cooling system checked at a guess I would say this is water leaking into the cylinders which indicates a cylinder head gasket fault. A faulty cylinder head gasket would also cause slight loss of compression which could explain the loss of power. remove the oil filler cap on the engine if there is a sign of a light brown (cream) coloured substance (water contaminated oil) on the cap or in the cover then the head gasket needs replacing also check the dipstick.
Hope this helps.

NOTE: Water vapor will collected in the exhaust system and will burn it off as steam until the pipes get hot enough to boil it off when starting a cold engine. That being said:
you could indeed have a crack in the head, or crack in the water jacket. You may or may not be able to spot some contamination of oil in the coolent or vice-versa, i would check for that too.

Usually if there is water or moisture in the valve cover but not in the crankcase, you have a venting problem (PCV) or the engine is not warming up to operating temp.

It appears that you have a minor leak at where a hose attaches to an engine or radiator pipe. When the engine is hot any leak will evaporate quickly and therefore not be seen. As the coolant heats up it will expand into the overflow tank but once the engine is stopped the extra heat build up will force the coolant out the leaking joint. As the engine cools, the leak prevents the coolant from being sucked back from the overflow tank.

The heater hoses and those pesky little bypass hoses in the cooling system tend to go hard and split if they are over 10 years old. Check all hoses and clamps for a good tight fit and replace any hoses that have gone hard or have become soft and stretched. Those spring type hose clamps tend to be less effective in clamping as the hoses age. Worm drive ones are the best to use.

If unsure take vehicle to a cooling system specialist and have them do a pressure test and more thorough diagnosis.

If problem persists, then it could indicate a problem with the head gasket (Usually caused by allowing engine to become excessively overheated when cooling system has run dry) allowing very hot high pressure combustion gases into the engine water jacket, which super heats the coolant in the engine block, which then boils off, and is released via the cap or any leaks. If the head gasket is really bad it will leak water into the cylinders and into the oil in the sump. This is indicated by an emulsion of water and oil mix on the dipstick. You will also see white smoke (water vapour) from the exhaust.

your system can actually hold pressure for a long time, even after it has cooled. take the cap off and start the moter, if it shoots coolent out you have a problem if not you are fine.

There is a TSB for this problem. Here it is.

Bulletin No.: 04-06-02-007

Date: August 11, 2004

TECHNICAL

Subject:
Low Engine Coolant Level Indicator Always On (Diagnose Low Coolant Level System Operation/Check Sensor for Oil Contamination)

Models:
2000-2002 Buick Century, Regal
2000-2001 Chevrolet Lumina
2000-2002 Chevrolet Impala, Monte Carlo
2000-2002 Pontiac Grand Prix
2000-2002 Oldsmobile Intrigue

Condition

Some customers may comment that the low engine coolant level indicator is always illuminated.

Cause

The cause of this condition may be due to engine oil contaminating the coolant. Possible sources of oil contamination are internal engine leaks, improper service procedures, or the addition of some types of anti-leak additives to the cooling system. Once in the coolant, the oil leaves deposits on the level sensor creating an insulating film. This film results in a false activation of the coolant level indicator.

Correction

Diagnose low coolant level system operation and check the sensor for oil contamination using the procedure listed below.

Important: No coolant supplements should be used in GM cooling systems, other than what is approved and recommended by GM. The use of "aftermarket" over-the-counter sealing and cooling supplements may affect the operation of the low coolant level sensor. Discoloration of the coolant recovery bottle is normal and does not necessarily indicate that coolant contamination is present. Flush cooling system only when instructed by this bulletin.

1. Verify that the coolant is at proper level in the radiator and the coolant recovery bottle. If the coolant is low, add proper amount of 50/50 water and DEX-COOL(R) mixture. If the low coolant light operates properly, diagnose the cooling system for loss of coolant as outlined in SI. DO NOT proceed further with this bulletin.

2. Remove the low coolant level sensor. Refer to Coolant Level Module Replacement in the Engine Cooling sub-section.

3. With the key on, the engine off and the coolant level sensor disconnected from the vehicle wiring harness, observe the low coolant light:

^ Light is on - Chassis wiring or instrument cluster concern. Follow the appropriate diagnostic information in SI.

^ Light is out - Proceed to Step 4.

4. With the key off, connect the coolant level sensor into the vehicle's wiring harness. Connect a ground wire (1) to the battery negative terminal. Using a sharp probe (3) attached to the ground wire, ground the coolant sensor probe (2) as shown in the illustration. Make sure a good contact is made. With the key on and the engine off, observe the low coolant light for at least 15 seconds.

^ Light is on - Replace the low coolant sensor and re-check system operation.

^ Light is out - Proceed to Step 5.


5. Using a small wire brush or emery cloth, polish the low coolant level sensor probe to remove any film or oxidation. The probe should be a bright brass color when finished. Use Brake Parts Cleaner to flush removed deposits from the low coolant sensor probe. Re-install the low coolant sensor into the vehicle and proceed to Step 6.

6. Flush the cooling system and install new DEX-COOL(R) mixture as outlined in the SI. Check the vehicle's warranty history to determine if any engine gasket had recently been changed. If there has not been a recent gasket replacement, locate and repair the source of the engine oil contamination.

The reason you have high suction is probaly due to contamination in you a/c system. To clarify contamination, I mean water, other gases, or anything else, there only two things that should be in your a/c system, refrigerant and oil, anything else is a problem and will change your suction pressure.

If you can prove these items are true, then you need to examine that your condensor is cooling and condensing the high pressure gas, the tev is working correctly, and your high pressure is normal, and cooling is excellant.

Hi myxj87 -

It is possible that you have motor oil leaking into your cooling system. A common cause of this condition is a bad head gasket. Since both coolant and oil flow through the cylinder head (through their respective passages), a bad head gasket would allow for cross-contamination. Does the car still run well? Have you noticed any coolant in the oil whilst doing oil changes?