Backstory: truck has new t stat, hoses, overflow tank, cap, replaced plastic lines with rubber hoses.

I'm going to do a combustion gas coolant test tonight but thought I would run something by you guys.

Last night I replaced the plastic line from the top of the radiator and topped off the system, let the truck idle until my buddies scan tool said it had hit 194 degrees. At this temp, the radiator and lower hose were stone cold. It staid like this for at least 5 minutes. I continued to let it idle and watched the temp closely. After holding the throttle open and keeping the revs around 2500 rpm for a couple minutes at a time the radiator very slowly started to warm up, very slowly. I was only using my hand as a tester and didn't touch every inch of it but most of it did get warm eventually. During this time, the heat never went above 194, but the hoses seemed very firm.

Drove the truck home, noticed that again there is water on the frame rail and some residual around the bottle cap. So it boiled over on the way home. Only a distance of 5 miles. So today I noticed that the plastic line from the throttle body to the tank was leaking, so I replaced it. At this point I was hoping that this air leek may have been causing the water to boil. Got to work today, popped the hood noticed nothing wrong but the lower rad hose was cold. So revved the motor from the engine bay to around 3k, and after about 2 minutes the water quickly boiled over.

to me this sounds like it could be either a radiator or a head gasket. No glycol smell or smoke from the exhaust, no water in oil.... So small leak into water jacket or clogged radiator right?

 

Also, did not top off the coolant after changing the leaking hose today. Simply didn't have time. Would only removing that hose have introduced enough air into the system to cause this latest boil over? I wouldn't think so but I'll be damned if this isn't the wackiest cooling system I've ever delt with

 

What temp thermostat is the new one? If same as old, I would try putting the old one back in to see if problem is repeatable or improves. If improves, then possible defective thermostat. If no change then try a 180 degree thermostat to see if you can lower that 194 level some and open radiator flow sooner. As I recall, I think there is a small amount of flow from the radiator when thermostat is closed. This will eventually pull some heat into the radiator which may be what you felt, but thermostat is still "closed". Without opening, the higher rpms overwhelm the system as the bulk of hotter water is shunted through the bypass hose (which is there to quickly heat the engine from a cold start for better emissions). Additionally, an and/or on the preassure cap failing or a gasket/pinhole leak lowering the preassure and the boiling point.

 

It's a brand new, genuine gray land rover brand, 180 degree t stat.

 

Definitely a head gasket. Failed the combustion leak test..... Damn

 

Sorry to hear it failed combustion leak test,
At same time it's weird that all this happened right after you only changed a plastic line,
did it ever had any over heating issues b4 that,?

 

I was having issues with disappearing coolant (pretty slowly but still evident) and eventually noticed that there was water coming around the bottle cap. So replaced the reservoir & cap hoping that was the issue. When I went to bleed the system, after all the big bubbles were evacuated, the coolant would still slowly dissappear from the upper hose, slow enough that if you just topped it off and put the screw in you wouldn't notice it. So assumed small air leak somewhere (at this point I had already decided it was prob a head gasket but I didn't want to believe it) and the small plastic lines were literally the only thing that I hadn't been replaced yet.

That pretty much brings you up to speed. Damn I'm pissed. I don't have the money to have the block welded and re-sleeved if this goes beyond the gaskets. If I were a dishonest man I would strongly consider throwing stop leak in it and panning it off on someone else but I can't do it.

 

When I first bought the vehicle it had dex cool in it and was running hot but honestly don't remember if the water was boiling at any point. So put new coolant in and one of those crap thermostats. Threw the crap t stat away and got the genuine LR piece. Original bottle then decided to fall apart so got a new bottle, that one leaked from around the bottom of the fill neck. So repaired the oem reservoir, which seemed to work but then noticed the disappearing coolant so got the new reservoir, cap, upper hoses and t fitting, the works.

In reality it probably had the leak from the get go and just got worse over time. Surprised it's lasted this long honestly.
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Has anyone bought one of these ebay gasket kits? http://www.ebay.com/itm/182279832371

 

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