I have a 1995 Ford E-350 Cutaway Cargo Box Van with a 351ci (5.8L). I am having an overheating issue. My indicator gauge has normally run with the indicator at the "O" in Normal but recently began to overheat. On advice I replaced the fan clutch, thermostat and upper hose and temperature sending unit. Radiator cap is fairly new. Truck is still showing an overheating condition. Looking into the radiator, the new coolant is clean and green but overflows the radiator when the engine is running and with the cap off. Coolant rises and falls intermittently when engine is running. While replacing the fan clutch, water pump shaft was tight and no leaking from weep hole. Also there is no oil in the coolant and no water on dip stick so I am not thinking blown head gasket. I have not experienced a power loss however the engine is running slightly rough. No "steam" or white cloud at the exhaust and no water leaking. I am leaning toward a clogged radiator however I do not know where to actually look to solve this problem. Any suggestions?

 

Hi WW,
first be very sure the gauge is reading correctly. The coolant level changing sounds normal for the thermostat opening/closing.

If you can get use of an IR temp gun to measure the actual temp that would give you a better indication of real overheating. I chased intermittent overheating due to a bad gauge so I'm extra suspicious of just the gauge reading for troubleshooting.

jim

 

I'm with Jim here for the most part---first determine what sort of actual operating temps you have via an IR thermometer. If you need one uber-cheap (quality & price) I'm sure Harbor Freight has one for $9.95 or less.

During normal operation I'd think the t'stat should remain in one set position without modulating or "hunting" as the coolant level rise and fall suggests. Assuming the water pump impeller is spinning properly I've got to guess the radiator could indeed be restricting flow.

How many miles on this 351, any idea of its past maintenance history? Is the radiator original to the van?

 

Ok, my situation here is that I'm traveling through an area while trying to resolve this problem. I'm out of time for my own mechanical work so I took the van into a shop for diagnosis/repair. The van was previous owned by a contractor to DHL and was driven for package delivery. I have owned it since 2/09. The mileage on the van reads 270k but the engine had been replaced and was to have had about 30k on it when purchased. The radiator I replaced only three years ago. After writing this post, two pin holes were discovered in the top tank of the rad. A new radiator is being installed right now. An IR temp reading was taken on the top tank and on coolant showing 188° when hot. A test for exhaust gases in the coolant yielded no gases present. Besides the failing top tank, I'm favoring a blocked rad. versus a head gasket issue. Hopefully the radiator replacement will solve this problem as I need to climb over the pass from Sacramento to Truckee, CA on Sunday.

 

Let us know how the radiator replacement goes. My 2001 V-10 stays at around 200, give or take 10 to 15°.

I have a 99 Expedition that I swapped in a 32valve 5.4L and it has given me fits over the last few years. I had no problems for the first few years after the install (I installed electric fans at the same time, and I've always used good coolant...Zerex G20). The one thing that has helped tremendously is the installation of a coolant filter kit from Sinister Diesel. I had flushed the system many, many times before with small results. I was about to replace the radiator when I decided to try the coolant bypass filter.

The truck will still run hot in stop & go traffic with outside air temps at 95°+, but during normal driving, it is fine. The truck has the stock radiator, Flex-A-Lite electric fan setup, a temp gauge with a sensor in the block and Sinister Diesel bypass coolant filter kit, new 180° t-stat, stock/OE water pump in perfect condition, new radiator hoses, etc. No head gasket leaks, no mixing of oil & coolant. It just turned 100,000mi this month.

The general rule is that if the truck is *not* overheating while on the highway (sustained driving over 35-45mph), it is not a radiator flow problem. That is the general rule. I cannot say why the coolant filter kit helped so much in my situation, other than maybe I have some rust/scale build-up in the system (motor). But like I said, I've flushed the hell out of it, even with vinegar. Each flush helped, a little.

You want to be very careful about what you flush with, as a lot of stuff (not typical radiator flush, which is basically citric acid) in the car cleaner aisle attacks aluminum.

As for your truck puking coolant, that immediately sounds like head gasket. Granted, your coolant test disproves that, and 188° running temp is normal. A pressure test of the system both cold and hot would help, but not rule out any blockages.

I posted my story in hopes that it might help someone down the road.

 

Ok this may be a bit long winded but I want to explain what happened in my case. Being that I am in the midst of traveling and ran out of time to continue doing the work myself, I took the van to a mechanic. My issues even stumped this genius mechanic for awhile. What happened was this, the puking or overflowing of coolant was caused by an air bubble behind the new thermostat which would not allow coolant to flow. They replaced my new thermostat and drilled a tiny hole in the top of it to allow for air to pass through. The new thermostat I put in was sticking also (crappy Chinese made parts). This solved the flow problem. Also this was after the radiator was replaced due to a leaking top tank. The previous radiator could have been repaired but I didn't have time to wait for that. We opted for the new radiator. Anyway, after the thermostat was replaced, the overheating condition still persisted but the actual temp was 188° with an IR gun. The next problem was that the brand new temp. sending unit I put in was also defective (again crappy Chinese parts). After these items were replaced again and with the air bubble gone and new radiator installed, the van is running cool (between the "O" and "R" of NORMAL on the "gauge". The crappy parts by the way came from O'Reilly's Auto Parts and the new parts are from Napa. Napa also had the radiator with a lifetime replacement guarantee. Hopefully this experience helps someone else diagnose their confusing issue. Just glad it was not a blown head gasket!

 

I'll second the sigh of relief it wasn't a head gasket----great news on that front.

I've always opted for the better NAPA or Ford OEM parts, tend to avoid anything Chinese made if it all possible, cost is unimportant to me. Just as in your case Wild Weasel the small savings up front can really put a bite on the budget later on.

The other good news is you're back on the road with a good running van---hope the rest of the trip is (mechanically) un-eventful!

PS: Thanks for the update----might prove helpful to someone else at some point.