leaking coolant

i have a bonn 95 se 3800 every morning i go out and all coolant has leaked out over night no hoses or anything leak coming from around water pump but unsure car never gets to hot and coolant light never comes on but radiator is always empty and no heat obviously till i put coolant back in but i never lose coolant while driving drove from GA to OK the whole way i kept coolant in it but we stopped to sleep and then it was empty.any ideas?
thank you

The water pump is one of the weak parts on the 3800. If you take your serp belt and the water pump pulley off, you'll see 2 holes in the water pump housing behind the pulley. If you see signs of coolant seepage around those holes, the water pump seals have failed and that's where your coolant is going. If you see no leakage on the ground or around the water pump, and the 8th digit of your vin # is a K, then you may have a upper plenum that has cracked internally and is dumping coolant into the intake.

The water pump is one of the weak parts on the 3800. If you take your serp belt and the water pump pulley off, you'll see 2 holes in the water pump housing behind the pulley. If you see signs of coolant seepage around those holes, the water pump seals have failed and that's where your coolant is going. If you see no leakage on the ground or around the water pump, and the 8th digit of your vin # is a K, then you may have a upper plenum that has cracked internally and is dumping coolant into the intake.


Or check to see if there a plastic pipe going from the belt tensioner to the lower intake manifold,it has two o' rings and are known to leak,if it is replace the pipe and o' rings.good luck

The water pump is one of the weak parts on the 3800. If you take your serp belt and the water pump pulley off, you'll see 2 holes in the water pump housing behind the pulley. If you see signs of coolant seepage around those holes, the water pump seals have failed and that's where your coolant is going. If you see no leakage on the ground or around the water pump, and the 8th digit of your vin # is a K, then you may have a upper plenum that has cracked internally and is dumping coolant into the intake.


being a l36 as he stated...well technically he could have a L67 but that usually comes with the H4U RPO which would make it a SLE.

and actually vin k plenums melt usually instead of crack from what I have seen.

Also seen a considerable amount of issues with the TB gaskets leaking small amouns of cooling and also the uppers leaking..oh and dont forget the plastic coolant elbow lol.

have we been able to actually trace it to the water pump gasket?

thank you for all the replys.ended up being three problems.was leaking from water pump as rich said the gasket was crumbleing on the top and replaced elbow.lol.hope thats the end of it.hoping all this was in such bad shape from sitting for 2 yrs.
thanks agin

thank you for all the replys.ended up being three problems.was leaking from water pump as rich said the gasket was crumbleing on the top and replaced elbow.lol.hope thats the end of it.hoping all this was in such bad shape from sitting for 2 yrs.
thanks agin


All seems well but 2 years is a long time especially if it was out in the weather,check your brake lines,fuel lines,and all rubber hoses just to be safe,Good Luck