Oil In Antifreeze !!

2002 IMPALA 3.4 V6 130K MILES
I have been noticing an oily film in the overflow resivior for some time. It seems to have gotten worrse now. A pint of antifreese extracted from the overflow resivior has 3/8" of oil on the top after it settles in a jar. Could this be the intake manifold gasket? Is ther a way to tell if the intake gasket has been replaced already? The oil on the dipstick looks good, not milky at all.

Thanks for the help,

Dan

2002 IMPALA 3.4 V6 130K MILES
I have been noticing an oily film in the overflow resivior for some time. It seems to have gotten worrse now. A pint of antifreese extracted from the overflow resivior has 3/8" of oil on the top after it settles in a jar. Could this be the intake manifold gasket? Is ther a way to tell if the intake gasket has been replaced already? The oil on the dipstick looks good, not milky at all.

Thanks for the help,

Dan

when your coolant system is hot you should have 15psi of pressure..this then causes coolant to enter the engine oil....this is a normal intake/head gasket type failure..

IF you have a bad coolant cap which results in no coolant pressure I guess it is possible to have this reversed...

When was the last time you had your cooling system flushed?and are you sure that its engine oil?

Yes I am sure it is oil. I have had the car for about 35k miles and I have not had the coolant sytem flushed. I did however remove the overfow bottle and wash it out with soap and a bottle brush to get rid of the oily residue. at the time it was only a film on top of the coolant now it has gotten mush worse. I did not pay for a colant flush because I was planning to replace the intake manifold gasket and then have the flush done. Now I'm not so sure the intake gasket is at fault and I would like to be sure where the problem is before I take this thing apart. A seepage past a head gasket could cause oil to go into the coolant. I would hate to replace the intake manifold gasket and pay for a coolant flush, then find out it was acctualy a head gasket.

How can I test the preasure inside the coolant system?

Thanks for your help,
Dan

Yes I am sure it is oil. I have had the car for about 35k miles and I have not had the coolant sytem flushed. I did however remove the overfow bottle and wash it out with soap and a bottle brush to get rid of the oily residue. at the time it was only a film on top of the coolant now it has gotten mush worse. I did not pay for a colant flush because I was planning to replace the intake manifold gasket and then have the flush done. Now I'm not so sure the intake gasket is at fault and I would like to be sure where the problem is before I take this thing apart. A seepage past a head gasket could cause oil to go into the coolant. I would hate to replace the intake manifold gasket and pay for a coolant flush, then find out it was acctualy a head gasket.

How can I test the preasure inside the coolant system?

Thanks for your help,
Dan

the other cause may be transmission fluid in the antifreeze.....
check trans fluid for contamination....or loss...

A radiator shop can check for gases in the radiator fluid. This is a definate test for your problem. I've also used a pressure tester if you put 10 psi on the tester and run the engine it will normally pulse if a head gasket is leaking.

A radiator shop can check for gases in the radiator fluid. This is a definate test for your problem. I've also used a pressure tester if you put 10 psi on the tester and run the engine it will normally pulse if a head gasket is leaking.

the head gasket is another possibility....normally if the head gasket is blown with the coolant cap removed the antifreeze will start bubbling with the piston pressure on the gasket area effected..


also as the gasket leak increases the coolant gets so much air intrained that the water pump can't pump air and the engine overheats...

If the engine is running hotter this is a good possibility...

using a rubber band place a plastic bag over the coolant cap opening,,,see if it pulses...