Still Overheating after new fan and flush

[klaine1]

I have a 2004 Discovery with 150k. I replaced the Tstat several years ago because the plastic corroded causing a leak; both coil packs !? flushed the radiator and refilled with water wetter and orange coolant; got a new viscous fan, but the truck stills overheats in the car pool line. The temp will lower with the ac off. The coolant leaks i think from the valley gasket (slow leak). there's no water in the cabin. the hoses seem hard and hot - they lose pressure after sitting for a while. the last i checked, the codes said O2 sensors. they engine runs fine and doesn't seem to misfire. no white smoke, or milky oil.
i could use your help again!

 

[Disco Mike]

First, do a coolant pressure test to find and fix the coolant leak, then check your electric fan, is it working in stop and go traffic and or with the a/c on?

 

[klaine1]

finally got the coolant system pressure tested. the leak is coming from the head on the drivers side at back of the engine by the firewall. there's possibly a leak in the same head at the front of the engine. no leak from the water pump or trottle body. the electric fan runs when the ac is on. if i've idled for 10 to 15 mins, the fan will run for 15 mins once the truck is shut off. i guess i need new head gaskets!? should i have the heads resurfaced? and how much should it cost?
thx again!!

 

[Disco Mike]

Will you be doing the work or have it done?
With your mileage, heads should be checked, both for warpage as well as valve condition. Never just resurface the heads unless they are past factory specs, usually more then .002 or .003 out. Valves should be checked, but may not need to be done.
New 8mm plug wires, t/stat, hoses and all the other good stuff.
Let us know what you are going to do?

 

[Disco Mike]

Will you be doing the work or have it done?
With your mileage, heads should be checked, both for warpage as well as valve condition. Never just resurface the heads unless they are past factory specs, usually more then .002 or .003 out. Valves should be checked, but may not need to be done.
New 8mm plug wires, t/stat, hoses and all the other good stuff.
Let us know what you are going to do?

 

[klaine1]

Well, i let my wife drive the rover one morning and the coolant gushed out the back of the engine. If you pour coolant in the tank, it immediately pours out the back of the engine, almost as quickly as pouring it in. I have removed the valley pan and i'm about the take both heads off and have them checked. I wish i had a list of items i need to purchase for the head gasket project?! So far, dismantling the engine has been successful (except for the SAI which was severely bent). I tracked the shop manual. This is my first head job!

 

[Disco Mike]

You will need a new t/stat, a complete head gasket set, a new set of 8 mm wires if they haven't been changed yet, set of new head bolts, a bottle of either Water Wetter or Purple Ice and spark plugs.
I would look at Atlantic British for most of the stuff except the plug wires, for those go to British Parts of Utah and buy their STI wires.
If you have any other questions, send me your tele number and I'll call you.

 

[klaine1]

Every cylinder head bolt was extremely tight and required a cheater / breaker bar and a friend! 4 bolts were hidden under sludge and oil. The tools that worked best for me were a craftsman small breaker bar, 3 foot cheater (pipe) on the breaker bar, 5/8 impact socket, and short extension (plus short wobble extension near the firewall). Each bolt should be cleaned thoroughly with brake cleaner and Q-tips. I used an impact wrench half way thru the job which probably loosened the bolts and helped the most!
Before using the right tools, i used a 5/8 deep non-impact deep socket (cracked 3 of them), and i did not clean or oil the bolts. I stripped a head bolt and almost lost my mind! I tried to J B Weld another 5/8 bolt on top of the stripped bolt and let it cure overnight. The "glued on" bolt popped off immediately and was a waste of time. I finally used a craftsman 5/8 16mm Bolt-Out Plus (Nut Remover) and hammered it on the bolt. My friend pulled the cheater bar and breaker bar and i held the Bolt Out firmly on the stripped bolt and it came out!!!
Tomorrow i'll take the heads to the machine shop to see if they are warped. I bought an Air Injector Pipe on E-Bay for 21.00!

 

[Disco Mike]

Sounds like you will want to do a good ATF flush after you finish the rebuild. What oil have you been using and how often has it been changed?

 

[klaine1]

I never kept track of the oil being used - i'm guessing Pennzoil at the Quick Lube shop. I had my heads resurfaced, and valves reconditioned. I had the machine shop clean the valve covers, rockers, and push rods. I sprayed several cans of degreaser in the engine, and removed the lifters to clean. The shop reassembled the rockers and put new valve seals in. No other gaskets, seals, or o-rings were used on the heads (alot of gaskets, o-rings, and seals were not used in the gasket set from British Parts of Utah). I put the lifters and rods in out of order (NEVER DO THIS - ******* IN THE WIND!) I reassembled the lower and upper manifold with new gaskets, new plugs, and wires. The truck ran in limp mode and performance was poor. The error codes were 1884, 1451, 414, 1482, 445, 448, 102, 340. I ordered a MAS. The "new found coolant pressure" sprung a leak in a weak hose and the coolant pump gasket. I repaired the coolant pump gasket and hose. The valve train has a slight tick when starting the engine -- it silences once the oil is circulated. Im going to use a K&N filter. The Engine Management System fuse #2 in the engine compartment fuse box was blown and replaced. The truck runs great, all powers is restored. No need for the cam position sensor ($400) or the MAS ($200) i think. DAMN FUSE. I'll continue to look for metal shavings in my oil pan. MIKE YOUR THE GREATEST!!