white smoke after de-cat

96 disco 300 xs Just had a complete new exhaust system, and de-catted, and sealed egr, now im getting whitish smoke from exhaust, checked oil ? thats ok , im loosing water out of my header tank, it doesnt smoke on start u or accelerating till it gets warm then it smokes, head gasket was done 5000 miles ago but left thermostat out ?? do u thing the head needs re doing again.

IT has just failed mot on welding, which is now making me depressed, but not the smoke test that was fine?? HELP

Sounds like coolant loss could be the head gasket, are you sure its not the p gasket leaking can be difficlut to see as its tucked away behind the alternator.
Running with no stat is a bad idea as the coolant will not flow and cool properly the gauge will say it is okay but the engine could be locally overheating.
If you blank of the bypass cicruit it would be fine but i think the bypass is internal on the 300.


Lynall

cheers never thought of that i will look into that tommorrow

it will flow without stat just take longer to warm up by pass is before stat, white smoke for unburned fuel will hang in air while white smoke from water wlll disperse quickly,if head was previously very hot when gasket went theres a good chance head will move again if been hot enough to relax casting

found i was loosing water, put some sol x coolent sealent in smoking stoped, been running in it all day no leaks or smoke, even my car heater r hot now need 2 sort out welding

be careful 300tdi crack heads if cooked

thanks 4 warning, temp guage is fine, does not llose water, heaters lovely and warm, i will c how i get on and report back later