So over the last two weeks or so I've been losing coolant at about a gallon every 120 miles. I had a rough morning idle and some white smoke so I thought changing the intake gaskets would do the job. I drive about 200 miles a day so it took me a few weekends to get around to it. I dove in this weekend and while doing the job I checked the oil and found water in it. Now I had heard that sometimes this can happen with bad IM gaskets so I let it ride. I finished the job and the truck seemed to run fine but I'm still losing coolant somewhere. I'm also finding water in the oil again after about 150 miles. The truck never overheats and the heat always works. Could I be missing something? I'm getting white smoke in the morning but after it warms up theres no smoke. It used to smoke a little at stoplights but after the gaskets that stopped. What else can I do? I pressure tested a few months ago so I dont think its the HG
Water in oil but....is it really a HG problem?
- Thread starter Brains646
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retiredsparky
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Unless you are running an older engine, the intake manifolds on the LS motors do not have coolant running through them, so the gaskets have no affect on coolant, but are certainly a failure point on these reliable engines. This is one of the benefits of plastic parts which do not conduct the engine heat through the manifold.
The water pump could be leaking allowing coolant to get into the oil. You will find an ultraviolet dye that you can put into the coolant, drive several days, then use the ultraviolet flashlight to look for the bright yellow dye under the water pump, on the oil dipstick etc. The coolant may be dripping down inside the water pump housing into the oil pan. See the following source for the dye and flashlight or go to an auto parts store---
http://www.sears.com/search=radiator coolant dye 8 oz bottle
When you pressure tested, how long did it take for the pressure to go down?
When a head is warped or cracked, it may not leak when cold. Overheating aluminum heads will eventually warp them. A major source of scrap aluminum is engine heads. Some warped heads will return to original shape, most will not.
If the problem is the heads, don't use exhaust manifold bolts. The studs and nuts are only $12 for both sides and will be less likely to fail, no torque is initially applied to the studs--hand tightened. Torque the nuts, then if needed to remove the nuts, they can be ground and split to remove. After a steel bolt is installed into an aluminum head, galling can take place, locking the bolt in. A stud only has to have the nut removed to remove the head. Less chance of breakage!
If you can smell coolant at the exhaust pipe or use a tester for combustion gases in the coolant resevoir, you will need to pull the heads, have them pressure checked, checked for straightness. Rebuilt heads less than $200 each are commonly available-do not buy heads with the code number 706 in the lower right hand corner outside of the valve cover. They are "cheeseheads"-Castech brand and prone to cracking at the head bolt location right side.
Oh yea, don't drive this vehicle, coolant in the oil is not your bearings friend and will destroy crank and cam bearings. Coolant makes a bad lubricant. Rent a car.
Larry
The water pump could be leaking allowing coolant to get into the oil. You will find an ultraviolet dye that you can put into the coolant, drive several days, then use the ultraviolet flashlight to look for the bright yellow dye under the water pump, on the oil dipstick etc. The coolant may be dripping down inside the water pump housing into the oil pan. See the following source for the dye and flashlight or go to an auto parts store---
http://www.sears.com/search=radiator coolant dye 8 oz bottle
When you pressure tested, how long did it take for the pressure to go down?
When a head is warped or cracked, it may not leak when cold. Overheating aluminum heads will eventually warp them. A major source of scrap aluminum is engine heads. Some warped heads will return to original shape, most will not.
If the problem is the heads, don't use exhaust manifold bolts. The studs and nuts are only $12 for both sides and will be less likely to fail, no torque is initially applied to the studs--hand tightened. Torque the nuts, then if needed to remove the nuts, they can be ground and split to remove. After a steel bolt is installed into an aluminum head, galling can take place, locking the bolt in. A stud only has to have the nut removed to remove the head. Less chance of breakage!
If you can smell coolant at the exhaust pipe or use a tester for combustion gases in the coolant resevoir, you will need to pull the heads, have them pressure checked, checked for straightness. Rebuilt heads less than $200 each are commonly available-do not buy heads with the code number 706 in the lower right hand corner outside of the valve cover. They are "cheeseheads"-Castech brand and prone to cracking at the head bolt location right side.
Oh yea, don't drive this vehicle, coolant in the oil is not your bearings friend and will destroy crank and cam bearings. Coolant makes a bad lubricant. Rent a car.
Larry
Last edited:
Snowbound
Jim
Agree with what Larry said above. I would say, cylinder leak down tester will tell you if the spark plug doesn't tell you the story. I ran into the same issue putting aluminum heads on cast iron block and not running MLS head gaskets. Tearing it down that far always sucks, especially when you were just right there. Then waiting on machine shop to pressure test and resurface before being able to reinstall. But all that is better than washing a bearing and having to rebuild or replace the entire engine. Good luck and I hope you get ahead of it.
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