Running rough and electric fan not turning off

[Figman]

Hello there:

This is a new one for me; I leave work for a short ten mile trip to pick up something. On the highway I noticed the truck running strange a bit rough, no lights on the dashboard, temp gauge normal but driving different. The truck feels a bit forced. I got home and started to check under the hood, still not lights, overheating or any leaks, on the way back still felt the same sensation, I noticed the electric fan running continuously, left the hood open, is cold in New York so I figure as soon as it cools off the electric fan will turn off. Nope, left the engine running for about 30 minutes and the fan is not turning off.

Any ideas?

Thanks

Figman
Disco II ?01 ACE, SLS 86K

 

[ratboy]

failed fan clutch?

 

[eliaschristeas]

i know on older intake trucks (through 98) a bad coolant temp sensor/switch can make a truck run like balls as you describe. I have two spares in the cubby box....

if i'm not mistaken, yours is the one right smack under the rigid black coolant pipe - between the alternator and AC compressor. might be that......

 

[singingcamel]

Temp sending unit as described above and or fan relay. If the fan clutch was bad it out to roar like a jet.

 

[mbrummal]

Temp sending unit as described above and or fan relay. If the fan clutch was bad it out to roar like a jet.

or it wouldn't do a thing.

 

[brianhoberg]

my money is on the fan relay.

 

[nosivad_bor]

If the truck is running and the electric fans are on, first make sure that the AC is not on, as that will cause the electric fans to run.

 

[Figman]

Ok friends here are some updates,

I took the truck to my mechanic; when I drove to the shop the truck still felt sluggish. As soon as we opened the hood noticed all upper hoses on the radiator were hard (fat) full of pressure; they looked like they were going to explode. The lower hose was cold to the touch, if like coolant was not circulating at all. He plugged in the computer and he checked for codes on the engine, no codes; checked the temperature and it was reading 102F. Of course the electric fan was at full speed. He then open the expansion tank and left it open to release the pressure. At idle the truck seemed to be running hot at first, but the gauge inside stayed at the middle like always. Then he ran the engine at 3K RPM for a while and the temperature started to drop to 98F and the electric fan will stop. Once again back to idle and the temperature started to go up again but without the expansion tank capped pressure did not build up and the hoses were soft. He also tested the fan clutch and after a long while at high RPMs eventually kicked in.
Long story short… he believes my radiator is acting up, he put everything back together and on my 10 mile ride home the truck feel totally different, it feel smooth and “relief” it was running much quieter too. It is hard to explain. Unfortunately when I got home the electric fan was once again running at full speed. The guy told me to drive it over the weekend and to let him know. It could be the radiator but if I change it and the problem still happening I will be very upset.
The guy doesn’t believe I have a HG problem. Like I mentioned before I replaced all hoses, thermostat, expansion tank and cap back in March-May 2008. The radiator was replace by LR dealer in July ‘07

What do you think?

Thanks again

P.S. I am sorry if I don’t sound too rational but all of this is hard to explain.

 

[Najman]

Ok friends here are some updates,

I took the truck to my mechanic; when I drove to the shop the truck still felt sluggish. As soon as we opened the hood noticed all upper hoses on the radiator were hard (fat) full of pressure; they looked like they were going to explode. The lower hose was cold to the touch, if like coolant was not circulating at all. He plugged in the computer and he checked for codes on the engine, no codes; checked the temperature and it was reading 102F. Of course the electric fan was at full speed. He then open the expansion tank and left it open to release the pressure. At idle the truck seemed to be running hot at first, but the gauge inside stayed at the middle like always. Then he ran the engine at 3K RPM for a while and the temperature started to drop to 98F and the electric fan will stop. Once again back to idle and the temperature started to go up again but without the expansion tank capped pressure did not build up and the hoses were soft. He also tested the fan clutch and after a long while at high RPMs eventually kicked in.
Long story short? he believes my radiator is acting up, he put everything back together and on my 10 mile ride home the truck feel totally different, it feel smooth and ?relief? it was running much quieter too. It is hard to explain. Unfortunately when I got home the electric fan was once again running at full speed. The guy told me to drive it over the weekend and to let him know. It could be the radiator but if I change it and the problem still happening I will be very upset.
The guy doesn?t believe I have a HG problem. Like I mentioned before I replaced all hoses, thermostat, expansion tank and cap back in March-May 2008. The radiator was replace by LR dealer in July ?07

What do you think?

Thanks again

P.S. I am sorry if I don?t sound too rational but all of this is hard to explain.

mabe you have a faulty thermostat, try to drive it with cap of the expansion take remooved to release any air stuck in the system .
your fan is running all the time because the ecu is getting an order that it is hot .
mabe your water pump is dead i ve seen some that do not leak and the inside propeller is loose inside .

 

[DiscoArt]

My truck had the same problem and it turned out to be a cracked block. Do you have a waterfall sound in the dash too?

 

[Figman]

I thought it could be the thermostat but my guy doesn't believe is that, he replaced all hoses, T-stat, expansion tank and the cap back in may '08 chasing a leak on the overflow tank. The truck was leaking from the overflow hose attached to the tank (which is supposed to do that) but something was pressuring the system and leaking a lot. At the end I took the truck to the dealer and they determined that the expansion tank was bad and replaced again. The problem went away until now, there is no leak but something is pressuring the engine, back in July '07 the dealer replaced the radiator due to a leak according to them. So now I don?t know what else to do, my guy strongly think is the radiator that might be clogged. No waterfall sound.
Thanks again

 

[Najman]

I thought it could be the thermostat but my guy doesn't believe is that, he replaced all hoses, T-stat, expansion tank and the cap back in may '08 chasing a leak on the overflow tank. The truck was leaking from the overflow hose attached to the tank (which is supposed to do that) but something was pressuring the system and leaking a lot. At the end I took the truck to the dealer and they determined that the expansion tank was bad and replaced again. The problem went away until now, there is no leak but something is pressuring the engine, back in July '07 the dealer replaced the radiator due to a leak according to them. So now I don?t know what else to do, my guy strongly think is the radiator that might be clogged. No waterfall sound.
Thanks again

2 years and the rad is cloged i do not think so i hope you running coolant not water in your truck .

 

[DiscoArt]

Do a chemical block test to see if you have exhaust gases in the expansion tank. I had exact same symptoms as yours and after I pulled the head one of the pistons was nicely steam cleaned. My block cracked behind the liner and cooling system was pressurizing. Another simple test you can do is open the expansion tank in the morning when the engine is cold and see if there is any pressure in the cooling system.

 

[Figman]

Hello friends, common sense tells me that the radiator is too new to be defective but again anything is possible. Disco Art I am very concerned that could be something inside the engine that is causing the pressurization. My gut feeling tells me that it is something internal, I will ask my friend to bring the chemical test to see if we can find anything. Back in ?08 we did the same and the test showed nothing.
My guy told me to drive the truck, I warned up and took a short ride by my house about 3 miles, then I met a friend and soon after he started looking around. As he was checking around I showed him the upper radiator hose (already getting hard) then he opened the coolant reservoir and there some pressure already in the tank, all I heard was a short hisssssss from the pressure and the hose turned soft in three seconds.
To make things worst I just bought a car for my wife and I am in process of getting selling my old car, so the Disco is my daily driver, now I am debating of keeping the disco or what. Money is not there for me at this time.
I know the cooling system is a pressurized system but for how long is pressure supposed to stay in the system. So what do I do the test in the morning, just drive it the day before park it and then open the reservoir tank next morning? You are telling me that should to be any pressure from the night before?

Sorry for the long email

Figman

 

[DiscoArt]

Yes, open the expansion tank cap in the morning before starting the truck. There should be no pressure in the system. If there is you got a problem.

 

[ptschram]

DO NOT run the truck without the expansion tank cap, you WILL overheat.

I'm betting on combustion gases in the coolant. Start looking for an engine, it doesn't look good for our heroes.

 

[singingcamel]

Pull the heads and have a peek.
Worse case would be a cracked block or a slipped liner , look closely for a very small crack between the cylinders . A slipped liner may appear normal but on ocassion you will notice it dropped somewhat.
You are pressurizing your system with combustion gases which could be caused by above problems.
Look for a bad head gasket as well .If you have a head gasket blown look closely for a block issue in the area of the blown gasket.

 

[Figman]

I checked for pressure in the reservoir tank it has nothing. The truck still runs like crap but there are no obvious leaks; the temp gauge stays normal, the coolant level is at the mark goes up while the truck is running but after is off goes back to the proper level; and the electric fan seems to be fine. I spoke with my guy and he said to leave the truck for a couple days so they can take a look. I still don't think, they believe is something internal in the engine. I am going crazy with this...

thanks again.

 

[uglysteve]

Replace your thermostat, and see if things improve. A faulty thermostat is more likely than a bad radiator. If the thermostat is stuck closed, coolant may not flow by the temperature sensor, causing an improper air/fuel mixture, causing it to run rough..
If that doesn't change things, then I would do a compression test to look for a bad head gasket or cracked block.
Good luck...

 

[bmohan55]

slight hijack-quick question. The OP writes that the temperature gauge shows normal. Isn't the gauge really just an idiot light...either normal or over heated, not really a true gauge? I had an overheateing issue awhile back and that is what I was told.