Discovery 2 engine overheating after bleeding coolant- Help!?
Hi Guys,
I am relatively new to the board but have been reading the treads for years and have got lots of help from it.
Here is what I have just completed on my 03 Discovery.
-Previous owner had a sleeve replaced and the block rebuilt, heads rebuilt and new head gaskets just prior to selling me the vehicle.
-I have since decided to take on additional work as there were some oil leaks and such post rebuild. I just finished the following:
-Timing chain/gears
-Oil pump
-Water pump
-Thermostat (got the soft spring from AB)
-New pulleys
-New transmission filter/service
-Switched to rotela t6
-Re-did the PCV valve system
-Rebuilt the PS pump
-New coolant temp sensor
-New brake servo vacuum fitting
-New muffler
-All new brake pads and rotors
Needles to say its been a long winter and I want to drive this truck!
So here I am trying to bleed the coolant, thought I did it right, went for a drive and the needle on the dash started to creep up (scarry) by the time it got to 2/3rds the way up I stopped the truck let it cool down. Then got back to my drive way.
Let the truck cool down overnight, went back out this morning to see if by raising the coolant tank and opening the bleed valve I could get more air out. No air appeared to come out... Went for another drive and the same thing occured. This time I noticed that the lower rad hose was not nearly as warm as the top hose and cooled down very fast. Forgot to mention I am getting good heat inside the truck.
I have verified the proper belt routing. No issues there... Other problem I noticed was a big driveline vibration as I was decelerating with my foot off the gas at a stop sign. Will have to worry about that one after I figure out the overheating/coolant bleed Issue.
Please help.
I am relatively new to the board but have been reading the treads for years and have got lots of help from it.
Here is what I have just completed on my 03 Discovery.
-Previous owner had a sleeve replaced and the block rebuilt, heads rebuilt and new head gaskets just prior to selling me the vehicle.
-I have since decided to take on additional work as there were some oil leaks and such post rebuild. I just finished the following:
-Timing chain/gears
-Oil pump
-Water pump
-Thermostat (got the soft spring from AB)
-New pulleys
-New transmission filter/service
-Switched to rotela t6
-Re-did the PCV valve system
-Rebuilt the PS pump
-New coolant temp sensor
-New brake servo vacuum fitting
-New muffler
-All new brake pads and rotors
Needles to say its been a long winter and I want to drive this truck!
So here I am trying to bleed the coolant, thought I did it right, went for a drive and the needle on the dash started to creep up (scarry) by the time it got to 2/3rds the way up I stopped the truck let it cool down. Then got back to my drive way.
Let the truck cool down overnight, went back out this morning to see if by raising the coolant tank and opening the bleed valve I could get more air out. No air appeared to come out... Went for another drive and the same thing occured. This time I noticed that the lower rad hose was not nearly as warm as the top hose and cooled down very fast. Forgot to mention I am getting good heat inside the truck.
I have verified the proper belt routing. No issues there... Other problem I noticed was a big driveline vibration as I was decelerating with my foot off the gas at a stop sign. Will have to worry about that one after I figure out the overheating/coolant bleed Issue.
Please help.
http://youtu.be/rYicbEbM7n0
Hope my drive shaft arrives from lucky 8 soon along with my new grey 180 deg thermostat.
Ok I am at a loss…
I have done everything you guys have suggested.
I flushed out every hose with the garden hose including the rad to make sure everything was flowing ok.
I got rid of the old MotoRad Thermostat that everyone thought was defective. I installed the authentic Grey thermostat that I bought from Lucky8.
I bleed the system as per everyones suggestion… I.e fill the reservoir while holding it up while waiting till the fluid come out the bleed screw. Run the truck… Thermostat still doesn't open. The hose leading up to the bottom of the thermostat is ice cold. The one going to the top is boiling hot. I used a gauge to watch engine temp, got it up to 210 and said thats enough.
I don't know what to do anymore, I am so discouraged.
Please help.
I have done everything you guys have suggested.
I flushed out every hose with the garden hose including the rad to make sure everything was flowing ok.
I got rid of the old MotoRad Thermostat that everyone thought was defective. I installed the authentic Grey thermostat that I bought from Lucky8.
I bleed the system as per everyones suggestion… I.e fill the reservoir while holding it up while waiting till the fluid come out the bleed screw. Run the truck… Thermostat still doesn't open. The hose leading up to the bottom of the thermostat is ice cold. The one going to the top is boiling hot. I used a gauge to watch engine temp, got it up to 210 and said thats enough.
I don't know what to do anymore, I am so discouraged.
Please help.
Recovery Vehicle
Joined: Dec 2012
Posts: 942
Likes: 29
From: St. James, NY
You should verify that the thermostat is opening. Pull it and check its operation in hot water. You could also check the Motorad tstat and if it works swap out the LR gray one.
Last edited by acamato; Jul 21, 2014 at 09:22 PM.
The motorad worked fine in boiling water but everyone seems to think that the thermostat was still the cause for it not opening. My rad is a nissen one and is only a year or two old. When the truck is running and I open the bleed screw coolant comes out therefore the water pump is working and also pressure builds up in the top hose.
I am still getting air out everytime I bleed once the engine is cool tomorrow I will bleed again. But no collapse hoses. Even if I still had air in the system would the thermostat not open since the hose leading to it is hot?
Super Moderator
Joined: Jul 2013
Posts: 5,794
Likes: 211
From: dallas texas
As long as the hot coolant is on the stat it should open. Are you seeing circulation in the res. at all while it runs?
I'd raise the res up, remove bleed screw and let it flow for a few.
I'd raise the res up, remove bleed screw and let it flow for a few.
This is why I am frustrated, I will have to see if I see movement in the reservoir. I know that pressure builts up in it. Maybe running it with the bleed screw off will help. I just don't get why none of my thermostats open.
