IMHO the "stopz leekz" can cause a number of problems. When it works (and they do work sometimes), about a match head of material is needed to stop a leak. And the rest sinks to low spots in the cooling system. Could be the lower radiator passages, especially if calcium coated (non-distilled water) or sludge(dexcool). another place the stop leeks goes is the metering holes on top of the D2 stat, which makes it let engine overheat.

 

if there is stop leak in there order a new tstat and be prepared to flush the crap out of the system.
You say he put in a new radiator, timing cover gasket and water pump and he still used stop leak. Either he misdiagnosed the problem all together or everytime he closed one leak the new preasure open another.
I'm guessing it is the first "misdiagnosed" I would be putting a wrench on everything he touch, and while preasure testing I would be pay close attension in the areas that he worked on.
JMHO

 

Another point - if you have a code reader that shows live data or an Ultra Gauge, watching the coolant temp in digital fashion will tell you that things are going in the wrong direction sooner than watching the factory gauge. This helps when doing repairs, as you want to know if "this" made the difference, keeps from stressing the engine even more while you run down the multiple interactive multi-volume set of Murphy's Law... (you may have more than one issue). The factory gauge is made to show normal for a wide range of temps, like 135 to 235, or near that, keeps Nervous Nate from clogging up the service department.

 

Plan on replacing the radiator compliments of the fairy dust cause Rover radiators have very narrow veins and can't really be cleaned.
Also since you have mixed your fluid, better pull the pan and inspect your bearing, they may be damaged by the fluid mix.

 

To clarify, the fairy dust was put in about 9 months ago by a tire shop. 3 months later it started overheating and that is when the radiator, water pump, timing chain etc was replaced. that fix lasted about 3-4 months and then it started with the low coolant, no heat, wooshing sound under the dash with no external leak so we topped up the coolant and drove it for a couple days. Then it started to overheat once so we parked it and called the mechanic who did the work. He didn't even want to look at it. He just said it need an engine and offer us $1500 for the truck. It has now been sitting for a couple months and I am going to tear it down next week. I ordered a head gasket kit, new head bolts and a coolant pressure tester. I will plan on checking the thermostat. Any other parts I may want to have on hand?

 

The stat is a $40 or less item, probably should go new with that if not recently repalced, could have gunk in it, etc. You sound determined and prepared, have a copy of the RAVE, etc. Might want to consider at same time testing fuel pump PSI (schrader valve under driver rear of top intake), and mechanical oil pump PSI test. Oil pumps this age can develop cracks, some tick, and PSI is not what it needs to be. But it is enough to keep the oil warning light off.

 

Today's the day!! I am starting the tear down. My coolant tester adapter still hasn't shown up, so I am going to start by inspecting the valley pan and then the head gaskets. What size is the fan nut? My 32mm doesn't fit. Is it a 36mm?

 

When you get the heads off check for obvious slipped sleeve, you will be able to catch your fingernail on the sleeve at the top of the block, you really should chemical test before you tear it down, otherwise you still could have a dropped sleeve and not know it.

 

I got the intake off and much of the top end torn down. I had to go get a tool to remove the fan because the largest wrench I have is 36mm. I also am having trouble removing the fuel line fitting. I pulled off the green ring and there is a little square detent, but it doesn't want to come off. I should be in a position to remove the lower intake and heads tomorrow.

 

well you can save some money by calling and cancelling the preasure tester, it isnt going to do you much good now that you have torn into it the motor.