Reoccurring coolant leak - Torq spec/sequence

[borjawil]

1994 Ranger ext cab 4.0L 4wd

Current Info:

Burning coolant, replaced the driver head gasket and lower intake gasket. Fine for a couple hundred miles. Occurred again. Performed glove test on radiator. #5 cyl leaking. Replaced head gasket and coppercoted this time. Ford OEM lower intake gasket with black RTV on corners where head and block meet (front and rear) and on the surfaces of the block between the heads. Black RTV around coolant passages. New injector o-rings. New upper intake gaskets. New thermostat gasket at the block. Couple other new gaskets at throttle body, etc. After 1-2K miles its burning coolant again.

CEL Info:

CEL comes on when driving occasionally - usually at HWY speeds. This was occurring before due to a bad MAF and then an incorrect one. Correct one is believed to be installed now. Still getting CEL as before though it did go away for a while with the new/used MAF. Checked DTCs, only one for lean o2 on driver side. Not sure if thats due to o2 sensor or coolant burning on that side.

Coolant Reservoir and other symptoms:

One more thing i noticed. Heat isn't working, likely due to lowered coolant level. With temp gauge in high range no heat still. Loosing a lot of coolant I feel. no mixing in oil. where else would it leak from (obviously its getting in my cylinder since its burning). I also noticed that the reservoir cover is not sealed/deformed where the black top meets the opaque side and the overfill tube seal on top of reservoir is leaking/deformed. Assuming from hot coolant melting. Are there any issues with air getting in through here? I would assume it would affect the coolant system from creating a vacuum to suck coolant from reservoir to rad.

MAIN Questions:

I will be retightening the lower intake bolts again (driven 1-2K since last head/intake gaskets). Anything else I should check or do?

Will I show a blown gasket with glove test if intake gasket is leaking?

What is the proper torque spec and sequence for my lower intake and head bolts? Ive looked in the library on here and Ive also gotten information else where. I want to confirm these specs to make sure I didn't do something incorrect. Ive been told 13-15 and up to 22ftlb for the lower intake. Not sure if a range that great would affect it but I torqued to approx 16-18.

Thanks for sticking with me through that. Just wanted to cover all information for a better response. Ill get my glove test re-done and tighten those bolts and update.

 

[RonD]

No, Glove test only shows a Cylinder leak, i.e. head gasket leak or cracked head leak
Cooling system leak wouldn't show up

Rad cap installed pressure tester will show other leaks, including cylinder leak.
So do Glove test first then do Rad test


heater core is very easy to remove on 1994 Ranger, 2 hose clamps and 4 screws in cab
Remove the heater hoses from heater core at firewall, 2 clamps

Put a towel down in passenger side of cab
There are 4 screws, 8mm heads I think, that go up to hold lower heater core housing in place
Two on the left and two on the right
3 are low at the corners of housing
1 is higher up, right behind glove box, empty glove box and lower it down all the way to see this screw.

Also while glove box is down all the way check Blend Door, it is cable operated in 1994
Slide Heat from COLD to HOT a few times and you will see the cable moving the Blend door, you will also hear blend door opening and closing.
Blend door controls fan air flow thru the heater core, so if it is not working then no heat, or always heat

After lower housing is removed you need to pull heater core back to get it out of firewall openings and then tilt it to lower it out, coolant will spill out, thats why the towel is there

Flip heater core up side down(not in the truck, lol) and shake it a bit, if all the coolant/water is not draining out then passages are blocked, need a new core

 

[borjawil]

Thanks for the info. I have heat, coolant was just low I guess. Performed glove test. Moved slightly but didn't fill up and bob around. Re-tightened lower intake bolts. Still burning coolant. Unfortunately I'm a bit over 100miles from home so ill have to limp it back and see if anything changes.

 

[RonD]

Cylinder leak pumps "air" into the cooling system.
And air rises in a liquid
The air will circulate in the liquid until it gets to a high point in the cooling system, then it will stay there
Heater hoses are a high point
If enough air gets into a heater hose it will form an "air dam" which prevents coolant from flowing thru that hose so heater stops working
Higher RPM, water pump speed, can clear the air dam but it will return

Just a heads up if you notice heater output getting cooler, precursor to overheating as air builds up in the head, thats when over heating starts