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 !!!

 

The block innards are clean? No rust or scale?

Since the cooling system sounds solid, are the exhaust system and catalytic converter/s flowing freely? Engine isn’t running too lean? Ignition timing isn’t too far advanced?

Sixto
07 E350 5.4 183K miles

 

You replaced all those parts without verifying that you're actually overheating? I wouldn't count on a 45y.o. gauge to be accurate.

You mention a 'new sending unit' but also a 'busted up temp probe'. What kind of gauge does it have?

A good shop should be able to check to see what the true operating temp is. Or buy a good mechanical gauge to check. Does this year van have a shroud?

Have you done a system pressure test?

 

Thanks for your response!
- No i cannot confirm the block innards. The thermostat innards looked rust free, but that's as far as I got. I'm really hoping this is the last thing to check as I'd prefer to sell it and dont have a huge knowledge on engines.
- I have not check exhaust systems yet. How do I confirm this? I can smell an exhaust leak very seldom, but nothing worth battling the rusty bolts for. yet..
- Not sure how to check if its running lean, but the engine starts and sounds really nice. It also has a Holly aftermarket carb.
- Not sure how to check timing. I just assumed my mechanic did it correctly.

 

- Yea I did, sadly. The coolant boils over though, so shes hot.
- This makes sense as all the other gauges, other then speedo, read a bit wonky. Ive also taken the dash/gauge cluster apart and cleaned all the connections with contact cleaner.
- I have no idea what type of gauge. The sending unit is a 1" round acorn shaped sensor on the top right valve cover. Do you suggest I buy an aftermarket temp gauge? - Can it tie in to the existing sensor?
- The temp probe in question is in the photos below. I have no idea what this is for, but ties into a round harness below. See photos.
- Ok ill buy a handheld heat sensor on amazon. My mechanic just lets it idle in the yard and says its good since the needle doesn't go over half ideling.
- Yes fan has a shroud
- Never done a pressure test. A bit over my head.

--Photos--
1. Engine Overview
2. Random probe / wire I found wrapped up. Reminded me of a "Cooling Fan Control Module" thermometer/probe on RockAuto
2A. Cooling Fan Control Module on RockAuto
3. Acorn shaped sending unit for temp gauge
3A. Gauge
4. Random connection that was left disconnected since I bought the van. Blue end is female and is not native, but fits into the black (male) end. Only discovered this today!


Thanks for your time.

 

There are quite a few things that can cause overheating and you need to check them all in a logical order.

I would start by finding a shop that could do a good flush of the system. An old van like this it's a good chance it's all rusty/scaly as mentioned. What did the old radiator look like? Was it clogged up? Is the new radiator the right one for the van? Is the antifreeze the right mix?

Also should have the system pressure tested. If not by a shop then rent a pressure tester. Not that complicated.

Do you have a service manual?

This link gives a good overview for what to look for:

https://www.aa1car.com/library/overheat.htm

PS: Your van has a mechanical fan. Control modules are electronic devices so wouldn't be needed unless you have an add-on electric fan.

 

- Thanks for the link.
- Do you mean flush, like a coolant flush? Draining out every hose and area holding coolant (versus dumping the rad & thermostat)?
- I had my mechanic flush the system, as well I flushed it in the middle of the bush hoping it would help. Radiator did not have much crud in it, and the fluid did seem to run through it quickly, but not instant. The old RAD was old. The new RAD is an OEM match. Fit perfectly in place.
- Yes I have a service manual.
- Thanks for the tip on the control module. Any idea what the wire is in my photos?

Cheers,

 

Have any checks for a blown head gasket been preformed yet?

 

Other then seeing milky coolant or oil dipstick, no I haven't. I really hope this isn't it. I will get a pressure test done asap.

Thanks for the responce!

 

Here goes:
I've recently pulled my jeep out of mothballs which has a 304 amc v-8 engine.
Using my wife's candy thermometer I watched the coolant temp closely as engine warmed up. Yep, thermostat opened at 160-degrees and maintained.
Now, out on the highway, the engine ran along at 190-200 until encuontering a long uphill grade. My engine temps would raise to 220 and then continue on up to 240 where I would pull over at that point. The cooling system would Belch at least one-gallon of coolant in this process.

I changed most everything you did and began scouring the net.
I found a thread where a guy suggested having Stretched Head Bolts or a Small Crack which opens up at a specific tempurature.

Upon cleaning up my engine for detailing prior to install of a rodded radiator and new water pump I made an interesting discovery.
I found a head bolt with a missing bolt-head !!!!
So my engine is getting compression pressures introduced into the cooling system once the engine reaches 220-degrees.
Now I'm looking at pulling the heads and installing new head gaskets, and, having the heads checked for cracks.

 

^^^You might consider replacing the existing head bolts too. Not sure how one comes up missing a head but could be they're defective. Did you find the missing bolt head---should have been somewhere under the valve cover?

 

2CON,
I would put a bigger radiator in it
One rated for 500HP or so. An aluminum jobby. I got pissed at my van for overheating
Put a gigantor 909 radiator in it, now I have to run the crap out of it to get heat in the winter
Yours might have had heavy duty cooling system and the new radiator is not?

 

This is an interesting point and was my first thought after replacing everything cooling so far.

The radiator I put in fit perfectly and all holes lined up. It also looked fairly identical to the one I ripped out. I got it from Rock Auto and checked the specs before ordering. Can't confirm you're not wrong though.

If I go to a bigger one, I don't know how the fan shroud and everything will fit without some fabricating. I didn't want to go down that route until I had to. Hoping it was something else first. I my as well get electric fan and delete the old school fan.

Currently waiting for the new gauge to come in, hoping that I'm wrong still.

Thanks for your reply.

 

Thanks for this responce. I'm definitely going to check the head bolts later this evening.

 

The bigger radiator should be the same size, just thicker and the shroud and fan should work
The head gasket or crack issue greaser007 is talking about
You can do a laymans check just by removing the radiator cap cold and starting the engine
Observe the coolant in the radiator as the engine warms up
Any big air bubbles, or an old faithful of coolant out the cap, means you got trouble