2.9 Liter Engine; Excessive Water Consumption

Have a 88 Ranger with a 2.9 Liter V6. Has about 80,000 miles on it. Lately it has been consuming about a gallon of water per gas tank. Water is not leaking externally. Ran a compression test and all cylinders look OK. Removed the spark plugs, put the cooling system under 17 Lbs. of pressure and checked each cylinder for water and found none. While running this test the water level did drop in the radiator. Prior to running the above tests changed the engine oil and did not see any water in the oil. Engine runs well. Any ideas how I can determine where the leak is without tearing down the engine ??

Thanks,

Joe

Reply to
Joe
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Joe wrote in news: snipped-for-privacy@4ax.com:

Bet there's some steam coming out the exhuast pipe.

Reply to
donutbandit

How do the plugs look? Burning off coolant in the cylinder will do a good job of cleaning up the plugs. A wet hole will have virtually no carbonizing of the plug. (Not to mention the exhuast steam mentioned below.

Reply to
Marky

My 1990 2.9 cracked the head at #6 exhaust valve spring. The crack allowed coolant to enter under the valve cover. The way I confirmed it was to pull the valve covers, clean the exposed head surfaces, pressurize (pump-up) the cooling system, then check back in about

20 minutes. The tell-tale "green trickle" told it all.

Also found that the PCV valve and oil filler had a bit of "foam". Fortunately no detectable damage to internals. Have put about 30K miles on it since, with no further trouble.

This type of leak will not show any indication on plugs, nor will it show any HC in the coolant.

Pretty well known "weak head" problem to 2.9L enthusiasts.

Phil

Joe (tanque snipped-for-privacy@hotmail.com) wrote: : Have a 88 Ranger with a 2.9 Liter V6. : Has about 80,000 miles on it. : Lately it has been consuming about a gallon of water per gas tank. : Water is not leaking externally. : Ran a compression test and all cylinders look OK. : Removed the spark plugs, put the cooling system under 17 Lbs. of : pressure and checked each cylinder for water and found none. : While running this test the water level did drop in the radiator. : Prior to running the above tests changed the engine oil and did not : see any water in the oil. : Engine runs well. : Any ideas how I can determine where the leak is without tearing down : the engine ??

: Thanks,

: Joe

Reply to
Nielsen_Philip

Just a note about the 2.9 Liter. Removed the intake manifold planning to replace a noisy lifter. The intake manifold gasket was leaking between a oil and water passage. That was good news. The bad news is that on this engine you need to remove the cylinder head to replace the valve lifter, not nice, so decided not replace the lifters. In any case installed a new intake manifold gasket and no more water leaks and the valve lifter are quite most of the time, ocassionally one does not pump up for a while.

Cheers,

Joe

Reply to
Joe

Reply to
D F Bonnett

have a 93 taurus, had the same problem with always needing water.. had a few leaks like the water pump which did not hit the ground, it just went to the manifold/exhaust and burned off... also replaced the water pump and then the rad. cap... the rad. cap would only hold about 4 lbs. of pressure, should have held 16 lbs... with bad rad. cap.. the coolant would go to the overflow tank and then out the top of the tank when on the road... never did leak in the driveway so we could see it... after those two replacement parts and just about every hose under the hood there were no more leaks.... hope this helps.

Reply to
jim

OH, almost forgot, you said WATER LEAKS.. if you are not using coolant,

50/50 mix with water then you are just boiling away the water as it boils at 212 degrees, where a coolant mix might not boil until it hits 265 deg.. which might be where the water is going.....
Reply to
jim

jim wrote in news: snipped-for-privacy@noname.com:

Can almost guarantee a blown head gasket. A friend had this problem with a Scirocco. Water dropped regularly, no sign of leaks, no steam in the exhaust, no outward signs of where it was going.

It was still a head gasket, though.

Reply to
donutbandit

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