Buick Century 2001 intake manifold

trm7

My car is a 2001 Buick Century Limited, 4dr sedan, 6cyl automatic. Original miles on this car are 61,250 miles as of today, June 3, 2015.

When I purchased this car in July 2010, I had it inspected at my local maintenance shop and had intake manifold work done which now apparently needs to be done again. The amount I paid for this work in July 2010 was $ 811 + associated fees and tax.

In Sep 2014, I was advised that this same work needs to be done again. The shop inspection sheet noted:

• evidence of engine oil in cooling system
• further inspection revealed internal leak at intake manifold
• engine not equipped with oil cooler
• need to reseal intake

The shop recommended repairs and services: Intake reseal $ 879 (oil crossover) + associated fees + tax will bring the total to about $ 1000.00.

Perhaps this is normal for my car, but does this seem right to you that this specific work would have to be redone after just 5 years? The shop says that these things happen, and they advise me to get it done soon so that the cost doesn’t increase because of the additional damage I am doing to the car as I continue to drive it.

imidazol97

It's my understanding you have a 3800 engine--not the 3100. I'm not clear about what they found to be the problem this time. Do I understand that an independent shop replaced the intake upper manifold in 2010.

You say there is OIL in the COOLING system. This is not the same problem, or they didn't do it right the first time.

I recommend a different, trusted shop to diagnose. If you have oil in the coolant, it could just be the appearance of that because Dexcool, the orange coolant used by GM, can deteriorate if not changed and form a scum look or brown oily material that shows up in the coolant reservoir. It also deteriorates if earlier formula green coolant that is not compatible with the long life Dexcool and other new coolants is put in.

Also there is a powdered almond shell material recommended by GM put into the coolant to seal minor seeps. This was done at the factory or as a recall on some 3800's when factory had quit putting it in. The stuff is the same as Barr's leak powder you can buy at Walmart--it also contains water pump lubricant, which gives an oiliness that shows up on top of the coolant in the reservoir tank. I know because I've used the sealer heavily since my upper intake was replaced 5 years ago due to a small seep only when cold. I could see the oiliness from it.

So I'd recommend having another shop take a good look. Perhaps have them drain and replace your coolant with the Prestone light green yellow stuff called "Mixes with all Coolants." (The Mixes with all Coolants is the same as Dexcool but a light color.)

Try searching the internet for dexcool scum oil https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0CD8QFjAF&url=https://answers.yahoo.com/question/index?qid=20080428112119AA7QsMI&ei=LcNwVbnGBPDksATv4YKgAg&usg=AFQjCNEbHkZALZEuS1Jh6rVLjqJxlYctCQ&bvm=bv.94911696,d.cWc

It is possible you are getting red TRANSMISSION oil into the coolant from the transmission cooler that's inside the end of the radiator, but usually that's the coolant getting into the transmission and ruining things in there.

It is possible you are getting engine oil into the coolant in the cylinder head through the head gasket. The engine oil is under higher pressure and can transfer to the lower pressure coolant passage if there's a head gasket failure of certain types.

But I think you need a second opinion.

Have them write what they find and recommend.