The furious bubbling could be steam (which would explain negative combustion gas test). Could be thermostat (keep in mind that they have a small opening that allows gas or small quantity of water to pass even when closed). Could be water pump not producing enough flow, perhaps from messed up impeller, or restricted radiator. Could be radiator is partially blocked.

1. You can remove thermostat for testing with nothing in there, but a new one is about $10, probably worth swapping.

2. You can remove the water pump and inspect for the cost of a gasket. Get several for spares, or RTV.

3. You can check for hot/cold areas of the radiator, and run a can of rad flush through and back flush with garden hose. If any improvement, might point toward radiator going to the shop.

4. The water does run out to heater and back, any change with heat on max?

5. If you can get a scanner that reads live data, you will probably be amazed to see just how hot things are getting. But the numbers will make it easier to see incremental improvements from repairs. It must be getting really hot if 10W40 or 20W50 thins out..... Drive something else until you get this resolved.

 

YES YOUR RIGHT!
I think you should flow test your rad.

 

And, I suppose that in certain cases, it could be a thermostat installed backward. There would be small flow, from the "weep hole", and the thermal trigger point would be higher, because heat would have to conduct to the spring area via this small flow of water building up in the upper hose. When it opened, the overheated water behind would rush out, and could contain steam. Note: the spring side goes inside da block.

But in any case all the symptoms listed by the SurfRat indicate that if the vehicle is not parked until this is resolved, he won't be hangin' ten, he'll be walking. Do the math: 1 engine = "X" surf boards.

 

Thanks again to all of you. With somewhat cooler days the truck does not overheat. So I am now looking at either the radiator and/or waterpump. I located a used radiator cheap... will pick it up next week. Have it boiled out and recored if it neds it... and then swap it into the truck along with a new water pumpt and thermostat.

Will let you know how I fare.

Hav a brake question going into another thread.


BTW... the SurfRat name is not for a surfer. Here on Long Island... us surf fishermen call ourselves Surf Rats becasue we scurry along the rocks and jetties at night in search of the perfect 40lb bass.

 

Be careful as a fisherman along that type of beach, very easy for rip currents to form, if you find yourself caught in one (after falling in), swim parallel to the beach, usually 100 meters or so is enough to get out of the current. Many people get exhausted swimming against it, and drown. If you are out there a lot, you may see someone stuck it that situation. At night the puckerfactor would jump up an order of magnitude.

Bet the Rover is a great beach vehicle. In North Carolina I have seen 4WDs with multipile pole holders attached to bumpers, headed to the beach for surf fishing.

 

used to walk that hampton shore line throwing a line into the bubbling surf to pull out blues. caught loads of LI stripers but not from the beach. i'd kill for a few cut up stripers in the freezer right about now. i'm not even asking for fresh caught.

also did lazy bones out of montauk and 1 of about 7 amberjacks out of sheepshead bay. pound for pound there is no better fish than a striper.

 

...and one of my last mods will be a pole holder.