Intake gaskets leaking burning coolant?
#1
Intake gaskets leaking burning coolant?
I recently (as in yesterday) bought a 97 f250 with 145k. the truck is in pretty good shape and runs great. tonight i was driving home and noticed the white smoke from the tailpipe. not good. so as best as i can tell it loads up on coolant when the engine is in a high vacuum scenario. deceleration and idle. if you are accelerating the smoke clears up and goes away. the coolant that hasnt been burned away is nasty looking and smells strongly of gas. there is no sign of water in the oil as of yet. it also didnt seem like the cooling system was over pressurized. does this seem more like a head gasket or could it be the intake? my knowledge of these engines is lacking in comparison to my GM knowledge. i have owned one before but it was always great and never thought of giving me issues. any help is greatly appreciated
Ryan
Ryan
#3
i dont think its the heat exchanger. it is burning the coolant and the coolant has gas in it, not oil. the oil was quite nasty.
i have got the upper plenum removed and all of the harness and vacuum out of the way. the plenum has the coolant/gas gunk in it. is there a reasonable way that the coolant would get up into the dry plenum from a head gasket failure? it seems that it would have to be an intake gasket failure for that to happen. the only way the intake would get coolant in it from the head gasket would be the intake valve and if that is open the cylinder is in a vacuum. so it would suck the coolant into the cylinder but as cylinder pressure builds the intake has to be closed, effectively sealing the passage to the intake plenum. does this make sense?
i have got the upper plenum removed and all of the harness and vacuum out of the way. the plenum has the coolant/gas gunk in it. is there a reasonable way that the coolant would get up into the dry plenum from a head gasket failure? it seems that it would have to be an intake gasket failure for that to happen. the only way the intake would get coolant in it from the head gasket would be the intake valve and if that is open the cylinder is in a vacuum. so it would suck the coolant into the cylinder but as cylinder pressure builds the intake has to be closed, effectively sealing the passage to the intake plenum. does this make sense?
#4
So, new head gaskets and new intake etc. still blowing steam when i finally got it fired up about 15 minutes ago. i am about to go drive it off the side of a mountain. i am not sure about the heat exchanger thingamajig. would that cause it to blow steam? i dont even know if it has one. the lower rad hose doesnt tie directly into the WP but goes some box that seems as though its associated with the oil filer mount.
so any ideas as to why it would still be clouding the neighborhood and filling the pan with water?
Ryan
so any ideas as to why it would still be clouding the neighborhood and filling the pan with water?
Ryan
#5
#6
The box on the lower radiator hose is the infamous water to oil heat exchanger fitted from mid 89 through 1997 460 EFI engines. The steam and gunk is from two way leaks, oil into radiator when running, then radiator into oil when you shut it off hot. Look at this thread: https://www.ford-trucks.com/forums/9...r-failure.html
#7
it didnt really run long enough to open the thermostat but if the two were mixing in the oil cooler/heat exchanger i am sure it would show in the radiator as there is no block between the lower rad hose and the oil cooler box thingy.
as it is the water doesnt appear extremely contaminated. it does have a slight murk to it, but the residue from the first problem would also explain that. no obvious oil on top.
tomorrow i am going to pull the plugs and see if i get water from any cylinders. last time it was the back two. if there isnt any water in the cylinders i think i can guess that the intake system is possibly the culprit. i may also try pressurizing the cooling system and seeing if i can hear anything that could give me a hint. maybe ill get lucky and the leak will be obvious and squirt me in the eye or something...
Ryan
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#8
The box on the lower radiator hose is the infamous water to oil heat exchanger fitted from mid 89 through 1997 460 EFI engines. The steam and gunk is from two way leaks, oil into radiator when running, then radiator into oil when you shut it off hot. Look at this thread: https://www.ford-trucks.com/forums/9...r-failure.html
in the original condition the oil was contaminated. i think the intake gasket was to blame for that.
i read through that post today after i made my post here. good info, just not what i am fighting now i dont think
ryan
#9
you could have the cooling system pressurized with air from a comrpessor about 15lbs or so. i have made my own homemade fittings in the past and hooked it to a small air compressor, they sell airpump tools for this ,with complete silence you can hear the air leaking into the engine,i got rid of that oilcooler yeah its that stupid box looking thing your waterpump hose hooks to. not a good design too risky to have it in my opinion
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