Hello,

Ive put this post off for many months, but I've finally come to the internet. I need some help as I am stumped.

I have a 1978 E-250 Econoline Vanuguard Camper conversion. I purchased it with 50k on the odometer, but based on interior condition and general wear, its at 150k. The engine is the Windsor 351 5.8L.
The van had cooling issues from the beginning and I've slowly been chipping away at trying to fix it, but haven't had any luck. Ive actually travelled about 9000kms in total going no faster then 80km/hr this entire summer. I would need to neutral down hills and watch my temp at all times, pulling over every time I got near the first line of the (hot) gauge. I removed the thermostat for the summer but it would always eventually overheat with an hour. Mountain roads were 40km/hr max. A 7-8hr trip takes 11-12hrs.

NOTES:
- New Water Pump (replaced it twice. Second time seepage stopped after a gravel road.)
- New Thermostat Housing
- New Thermostat (tried 3 different kinds. Currently its a 180F and is installed the correct direction).
- New Radiator
- New 13psi Rad Cap
- New Sending unit for temp gauge
- Timing chain (overheating issues begun prior. Work was completed by mechanic.)
- New Heater core
- New Blower motor
- No coolant leaks
- no oil leaks
- Fan is functional. (No clutch fan on my engine.)

Less-related recent repairs:
- Alternator
- Voltage regulator
- Sway bar bushing
- Front brakes
- 3 battery setup to interior with inverter & external solar

I was certain it was the RAD in the end because I replaced that last, but now that I have the thermostat back in, I still overheat travelling across the city going 80-90km/hr.

Does this mean I purchased a lemon? What can I do next?
Do I upgrade the fan? Do I buy a bigger rad?

I just ordered a Cooling Fan Control Module on Rock Auto but I now understand that is for an electric rad fan.
I do see a pretty busted up temperature probe connecting to a round harness under my hood. Wires seem to be in tact but definitely some exposed wire and corrosion present.

Ideas appreciated. Let me know what photos you need.

Thank you !!!

 

As I suggested in the Van's sub-forum have you had the engine checked for a possible blown head gasket? Do I guess right that you've checked for oil/coolant mixing with one another from a cracked block or leaking through the radiator transmission cooling lines?

 

Yes, my coolant is not milky and my dipstick is pure oil. No pressure test has been done but I'm not leaking or loosing coolant.

Thanks again