Terminal Diagnosis 1998 4WD

[PVExpedition]

Well, this may be it. Expedition, 4.6, auto, 4WD, 251k miles, oil changed every 5-10k, auto tranny flushed & filter changed annually, have had the vehcile since 140k-ish miles....check engine light on & off the past few months...finally got it to mechanic today...combustion gas in radiator, inside valve cover is frothy, creamy, no water in oil pan......still runs ok. I am thinking of using a coolant sealant like Dur Seal, etc. What have I got to lose? Anyone have any experience with this stuff or similar products? I know it would be a temp fix but who knows? It might work and allow me to drive another 30k - 50k miles. Heck, it might go that far even without using the stuff. It might plug the water passages also. Who knows...snake oil? Worth the cost? $100 or so? Thoughts?

 

[jbanks]

Any codes related to the CEL?

 

[rburch]

Ive never been a fan of the quick fix stop leaks for the simple fact that its temporary and when it quits again its always at the wrong time and place and its usually time to scrap the caddy!

The price to fix it would be about the same as a low mile replacement! So maybe ask yourself if you keep it and fix it or deal with the time and hassle of finding something else.

 

[hammerg26]

I'm with rburch... what is the condition of the rest of the truck? If it is in solid shape, why not just replace the motor???

 

[toms89]

Best case scenario you just have a leaky headgasket. You could do a leakdown test to confirm. If so you would have to pull the heads to replace gasket to fix. It is very labor intensive plus the cost of gaskets, coolant, oil, etc... This would get you another who knows how many miles on the motor assuming its in good condition.

I have personally never used any stop leak of any kind so I am just speculating here but have serious doubts it would help a leaky or blown headgasket where combustion chamber breach is in question. (combustion gases in radiator)

I don't know that it would harm the motor though, other than the longer you run it with the leak the more potential damage it could do to the motor. Coolant can damage/ clog you cats fairly quickly if its passing through the combustion chamber. Also not a good lubricant if it gets into the oil system. If a head gasket really lets go you could hydraulic a piston and cause serious damage. Imagine your piston coming up on the compression stroke with both valves closed filled with slightly more coolant than the combustion chamber can hold. You cannot compress water so something has to give.

Then there is the question of the high miles on the motor. Is it time for a rebuild? Replacement motor? Or replacement vehicle.

Its a risk but with the alternatives you may have nothing to lose?!