P38 v8 Petrol Overheating

madbrit said:

yes that next is the next job Monday, pump water into the top, see what flow at the bottom, I presume that is the way, might just order another one anyway.

Click to expand...

madbrit said:

My V8 p38 petrol 51 plate started overheating for no apparent reason, I had the block tested with the blue solution, no leak into cooling system detected, so I changed the pump, old one was ok changed the thermostat, changed the expansion cap, changed the Viscous unit, all to no effect, still overheating, so I thinking the new thermostat not working, so got old one, bodged it so water flows through anyway permanently, still overheating, I did get rid of any air locks by taking off the top hose, heaters are working.
I am now at a complete loss, any ideas anyone ? only thing I have not done is change the rad ;(

Click to expand...

RangeRoller dt said:

You should test a new stat by tying it to a wire and dipping it in a pan of boiling water. should open fully at the temperature stated on the unit and close once cooled on its own.

Click to expand...

kermit_rr said:

And note the petrol one actually has 2 valves that open/close, one for the bypass and one for the actual radiator

Click to expand...

dubbleRR said:

If the rad is the same as a diesel one ,theres a baffle in the top that forces water down one side n up the other side ,if its failed then water just flows across the top ,,check the rad for heat at the bottom should be hotter at one side n cooler at the other , a scope and torch or marble test

Click to expand...

• Flush the whole system, not just the rad.
• Is it losing coolant or just overheating ? Any leaks will prevent the system getting proper pressure, and it will boil.
• Check the un-obvious like core plugs, underneath throttle body heater, etc.
• Also do a pressure test when the engine is warmed up, and not running so you can see any leaks.

pwood999 said:

• Flush the whole system, not just the rad.
• Is it losing coolant or just overheating ? Any leaks will prevent the system getting proper pressure, and it will boil.
• Check the un-obvious like core plugs, underneath throttle body heater, etc.
• Also do a pressure test when the engine is warmed up, and not running so you can see any leaks.

Air locks should be sorted by following the RAVE procedure rather than the top hose.

Click to expand...

Mark Piercy said:

If none of the above, a compression check on each cylinder with the Throttle wide open for any differences between cylinders.
Pull your rad out also and look for dead leaves mouse nests and dead birds jammed up in there reducing air flow. As said above.

Click to expand...

Mark Piercy said:

I thought you wrote peanuts

Click to expand...

oakey said:

Look up in where for a dead bird? Is that to check if dead?

Click to expand...

oakey said:

Look up in where for a dead bird? Is that to check if dead?

Click to expand...

tomcat59alan said:

My neighbour thought he'd hit a pheasant a couple of days ago,he stopped but couldn't find it, when he got home he as a proper look and found it had been forced through the plastic grill ( Honda) and was against the radiator. His wife wouldn't entertain eating it????.

Click to expand...