My E350 van keeps getting hot after driving about 100 miles.
Needle goes from about 1/4 to almost full hot in a matter of minutes but only after a 100 miles then it stays toward hot but will drop a little and go back up.
Have changed thermostat,flushed radiator and replaced cap.

Here's my what I was wondering what if I took out the thermostat,will it help or hurt?
Reason for asking is top hose seems to stay rather firm to hard all the time.(I Would think it to be squeezable when thermostat is open don't know)
Could it be clogged radiator still or maybe bad thermostat?
Would I get more cooling with out it?

Going to try to blow out dirt in radiator (Outside )and change serpentine belt (needs it anyhow).
Any thoughts?

 

Is the outside temperature changing significantly in this 100 miles? How many miles are on the vehicle? Have you tried changing the coolant temperature sensor? Those are usually pretty cheap. Alternatively, you could try testing the sensor but I'd be willing to bet you'd spend more time and money trying to test it than you would by replacing it (unless you have a transfer function or temperature vs resistance plot for the sensor and a non-contact thermometer).

If it isn't the coolant temp sensor, you probably have a water pump problem (perhaps a heavily corroded impeller that is not pumping as well as it should, a serpentine belt that is too loose, etc) or a blockage in a coolant passage somewhere.

Removing the t-stat will cause the engine to run cooler than normal operating temperature. This will likely result in a code being set in the computer and the computer ignoring O2 sensor input. This will likely have an adverse affect on mileage and emissions.

- Joe

 

1. you can pull t-stat out and drive without it. new ones have seals built into them, so you'll either have to jamm it open and reinstall, or seal with silicone sealant.
2. does your fan start? you have E350, so you probably have clutch fan, not electric fan.
3. temp sensor will be to suspect if fan does not kick in, or clutch in the fan itself.
4. radiator hoses should be same in temp on touch with t-stat open. if the engine shows hot, and there's significant difference in temp, then t-stat stays closed, or you have obstruction somewhere. hoses have steel coils inserted inside bends, to prevent them from collapsing, so you have to be particular where you try to squeeze it. on MANY cars upper hose is empty and even collapses some on cold engine.
5. if all of the above checks out fine, you might have exhaust leak into the coolant through bad head gasket or intake manifold one, as some cars have coolant running through intake to warm up gas/air mix. looks like beer foam in the radiator when t-state opens.

 

So you can drive 100 miles and everything is good?, and then once you get to a 100 miles it starts in with this? Can you describe this 100 mile drive?

 

All highway ,75 miles per hour,There's about a 15 mile stretch at about 55,After this I pull over and let it set for about 20-30 minutes(Temp gauge goes down) and take off again,then it will get hot again in about 30 miles or so.

 

Do you think it will help the over heating at all?

Yes sir ,running good.

Not sure on this one but will check it out,have noticed top hose is firm to hard.(pretty hot)Bottom does have spring in it.

Can't take cap off with out it over flowing
with engine running warm enough to open t-stat.

 

lots of good ideas. is it an automatic with a cooler in the radiator? is it air cond. with condenser in front of rad.? are they clean? does it get hot with and without the air on? if the top hose is hard with stat open, i'm thinking restriction either in rad.(dirty/clogged), bottom hose collapsing after it gets hot( hoses can separate and the inside close off the flow and not be noticeable from outside). bad water pump(impeller slipping) or clutch fan not working properly. how about a leaking head gasket??? at the exhaust valve??

 

You don't need the fan going once you are at highway cruising speeds.

What you DO have to have is unblocked outside a/c fins and radiator fins.

That coolant level is full in vehicle in radiator and engine - air pockets removed, and the overflow reservoir at proper level, and you know where it is, when you start out on your trip.

Then when it overheats, where is the coolant level in the reservoir?: Simply higher than when you started?, or is it up to the top and overflowing it?

Would like to know if coolant is being lost.

Your foaming issues. Have you added different bottles of stop leak? If not, likely head gasket blown or crack between water jacket and combustion chamber, with air getting in with coolant, acting like faucet aerator on your sink which also causes a foaming-like action. Coolant foam is not going to cool as well as pure liquid coolant.

Some shops are capable of testing if exhaust gases are getting into radiator, if you still are not sure.

 

I have no idea who have idea to take the termosat out of the engine the answer is DO NOT remove it pretty good percentage of the engine need the thermosat to run the coolant system propely due some of them have build in bypass port if you take them out you will overheat the engine.

really very simple check the radiatior to see any kind of debries blocked air flow use either blow gun or water hose and spray it oppisne way ditto with the A/C condensor as well [ if have it ]

over the time the raditor cores will get partally or fully blocked [ they start at the end where the water flowage is slow that when they start then work it way to close to the hose.

what tempture thermosat you install in ??

you should get one of the thermal gun which it will read the tempture right on the spot it should open pretty close to the spec.

sometime the tempture sensor can go bad and give you a faluse reading on it.

Merci,Marc

 

In my experience, most highway overheating problems has been due to a stuck fan clutch. When your going slow, you need your fan blowing on the radiator. When your going highway speeds, if your fan clutch is stuck, the fan is actualy preventing air from getting to your radiator. Easy way to check is when your engine is at normal temp (not hot!), shut off the engine and try to turn the fan. It should turn FAIRLY easy. If it doesn't turn at all (even cold) it's definetly bad.

 

It is higher and bubbling (like pan on stove)But it is not overflowing.

 

I would expect a clogged radiater also as they age they build up deposits that can't be removed by just flushing, in the old days a radiater shop could remove the tanks and rod out all the cores removing this buildup but on newer vehicles
where radiaters are often plastic or aluminum this isnt usually fixable and may require replacement.
first signs of clogged radiater is usually overheating only under a load this may be as little as turning on the a/c to actually driving on the highway or both, they can usually idle all day long without a problem but as the engine starts working, more heat is produced and it takes a good radiater to remove it.
while the fan clutch shouldnt be locked up on a cool engine but even if it was it wouldnt cause an overheating issue while fan clutches has been around a long time if you go back 35-40 years vehicles didnt even have a fan clutch.

 

I reccomend you go to the autoparts store and get a bottle of this stuff (forget teh name) you put it in the rad and it will lossen all the corrosion rust and gunk so you put it in drive 100 miles then flush the radatior.....its worth a shot