98 Discovery Overheating (please help!!!!!)

[gadiscovery]

I cannot figure it out. My Disco wants to overheat when in stop and go traffic. In the past two weeks i have replaced the fuel pump, passenger side exhaust manifold, valve cover gaskets, put on two ten inch aftermarket cooling fans, (wired them to start up when i crank the truck), dropped the transmission pan and replaced the trans filter, replaced the temperature sending unit, and thermostat. I have also spin tested the fan clutch, I have drained the radiator and used the flush that you buy from Autozone or any other parts store. I have run it with the thermostat in and out. It still runs hot. I do not have any water in my oil and i know because i changed my oil this week too. I don't think that i am losing water anywhere and my water pump is not weeping. It doesn't smoke and i cannot smell antifreeze when it runs hot. So i don't think that i have a blown head gasket. Any ideas??????? Before i rip the motor apart to look at the head gasket and intake gasket? By the way it has 170 thousand miles on it.

 

[Disco Mike]

Not to be a smart ass, but which directs are the fans moving the air and what is the air flow rating of those new fans?

 

[gadiscovery]

they are pushing are the right way, i checked them thinking i might have had a ****** moment putting them in. Not sure about the airflow rating on them but they look like they push more than the ones that came on it. The engine will actually cool down if it sits at a red light long enough. but wants to heat back up when it takes off. so in town where red lights are close together and don't last long it never sits still or gets going long enough to cool.

 

[joey]

Sounds like either the water pump is getting old or the radiator needs replaces... have it flow tested.

 

[Va_Disco]

I also have had over heating problem sim to yours on both of my discos. My 1997 Disco's problem was the water pump was missing a few fins and was not getting the right water flow (but the pump was also not weeping). My 1999 disco D1 was also over heating but had a new water pump and thermostat , I took the rover to a local trusted radiator shop and had them do a high pressure flush, The result was alot of crap shooting out of the heater core line. The problem with the do it yourself flush is you never get enough pressure to push all the crap out. But the shops use water and air pressure. I am sure you could rig something up and do this at home, but it only cost $65 for the flush. Both of my disco's would build pressure and spill coolent out of the coolent tank.

 

[gadiscovery]

I will have the radiator flushed and then check the water pump. Do you know what a waterpump costs. It does look like the water pump has been replaced at some point. Does your disco have a closed system meaning the coolant tank has a cap on it that will not let the coolant actually spill out of the tank?

 

[Va_Disco]

I got both of my water pumps form this company and have been very happy with them and they were $57.99
http://cgi.ebay.com/ebaymotors/LAND...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
or you can get one from Adlantic british for about $109.95
http://www.roverparts.com/Parts/STC4378A.cfm
My disco has the standard Land rover pressure cap ( meaning if the pressure gets to high it will alow the coolant to ecape to prevent damage any where else.

 

[Va_Disco]

I will have the radiator flushed and then check the water pump. Do you know what a waterpump costs. It does look like the water pump has been replaced at some point. Does your disco have a closed system meaning the coolant tank has a cap on it that will not let the coolant actually spill out of the tank?

If you are concerned about your head gaskets you can have that tested befor you have your syster flushed. They use a dye and test the coolant for any exhaust gases.

 

[greg409]

If you look into the vent plug on top of rad (pass side, while it's running , you should see flow (coolant moving)

does the upper hose get hot?

Throw the stat in a pan of boiling water - make sure it opens.

recheck the routing of the serp belt, I've heard it can be routed & make the waterpump run backwards.

Re- flush your cooling system, I flush the chem out by putting a garden hose into upper hose connection of rad & let the stat housing hose dump on the ground.

luck,greg

 

[gadiscovery]

I just got off the phone with my mechanic that is working on it. He said that he took the fan clutch apart and said that the spring in it looked weak. I guess that i will replace the waterpump, the fan clutch, and have the radiator flushed and pressure tested.