Head gasket issues
 

Ok i had issues with the headgasket about 1.5yrs ago and fixed it by gutting the thermostat. This worked great except for the truck wouldnt heat up in the winter very well. Now i was driving it yesterday and it heated up and i shut it off right away after i saw the gauge going into the red. It had zero coolant like it had just pushed it all out the overflow. I added coolant and it seemed ok for a while yesterday. Now it will overheat and push all the coolant out withing a few minutes of highway driving. I know the thermostat isnt blocked because its hogged out. I know the waterpump is working because its steaming hot when it overflows. Now why would it be pushing the coolant out. Lets say its a headgasket. why isnt the pressure from the leak just venting to the air vs pushing the coolant out with it. The hot air should rise up into the coolant overflow and just vent it shouldnt push out the coolant. This is my beater deer hunting truck and i drive it to work a couple miles a day. Is there a stop leak that guys have been successful using in our trucks. I read k seal and a couple others but wanted to hear from successful guys and gals. thanks Kevin

If this is a D1, it has a copper & brass radiator. You can remove it yourself, take to indy rad shop, and have it acid boiled and calcium rodded out, about $70 near me at a small place that does tractor and heavy equipment radiators. Your cooling system is clogged up, and has been hidden by running with no stat. That keeps temps at 130 - 140 F (when I tried it).

If you don't flush the radiator, most stop leaks products will seal up the lower rows of tubes that are full of gunk and barely flowing. Then, with 1/2 a radiator, you will overheat more.

If you are going to use stop leak, the Kseal has the minimum quantity of material to be left over and try to clog things.

The physics at work involves steam - which increases volume as it expands - and pushes the coolant out of all available spaces.

So can you try stop leak? Yes. If your coolant system is not in great shape, it will make overheating worse.

Should shut off before it gets to red. Way before. When mine is just above mid point, it is already 236 F.

It's a disco 2. I just am not sure if it's a hg issue. I do alot of drag racing and have nuked many headgaskets. They have all milkshaked the oil. My oil is clean. How can a headgasket issue not let oil and coolant mix together. It can't be a one way deal. Thanks for any info.

ok. Then aluminum radiator - so you may have to replace radiator, if it had dexcool in it there could also be sludge. With the opened up thermostat, did you close off the top bypass line, might add to the problem. See attached coolant flow. Pix of external HG leak, could have made you low on coolant, down the back of engine (maybe even just valley pan gasket), then boil over and overheat.

Compression test? Coolant pressure test? Borrow testers from auto parts store.

So your not thinking head gasket. It's been replaced about 30k ago.

You need to do a coolant pressure test to verify a leak.
I would get rid of that t/stat and go to one of the newer after market units that will flow more, run cooler up allow the ECU to go into close loop for more power and better mileage.

I am borrowing one tonight. Do I need to refill the coolant or leave it a little low to test. I would assume if it was leaking gases into the coolant system lime it looks like it is then it should show up pretty quick. I did it when it was overheating before and the color didn't really change much from the blue. Thanks for the replies. Where can I get the newer style t stat

see Installed 180f thermostat in place of 192f thermostat - Land Rover Forums : Land Rover and Range Rover Forum. You could have an external leak, down back of block, etc., that gets burned off. No white smoke from tail pipe, no milkshake oil. But good coolant loss, and in a hot environment you may not notice. Then truck overheats (low coolant) and boils over (steam). An HG can leak into air, into cylinders, into oil, or all three.

I got to dig into it a little. First thing I did was try to open the overflow cap. It still had tons of pressure in it. I mean had to go really slow to get it to not burp out all the fluid. This is leading me to think radiator issue or something other than head gasket. If it was the head gasket it would have bled the pressure off while it sat. It sat for 18hrs. There is no way it would have held pressure that long if there was a way to bleed it off Aka headgasket. I basically pressure tested it for a day if you think about it. I'm still going to check the overflow for exhaust gas.

Wrong, the radiator, although possibly restricted can not cause pressure to build up and hold it. Go do the coolant pressure test with the system full of water/coolant, if it fails and you want more proof then do a chemical block test for exhaust in the coolant.

Thanks disco. I would think a pressure test was done when it held pressure for 18hrs. I'm not talking a little. It was trying to shoot the coolant out as I opened the cap. I had to close it quickly it was coming out so fast. I basically have no thermostat so the entire system is under pressure. It never white smokes on startup and I did a block test with the blue dye last night and it didnt change colors at all. It wouldn't overheat when the cap was off and I put the cap on after I shut the truck off and it started to build pressure quick. I tested the temps on the radiator and the driver top was super hot and the passenger top was ice cold after the truck was up to operating temps. Could there be an air pocket? I have not been filling it the proper way since this issue started again. I have been just filling up the overflow and trying to limp it home. Thanks for any info. Kevin. Oh and I'm gonna try to flush the radiator tonight and see if it's gunked up. Any special ways you would suggest doing it. Thanks

Rather than air pocket, it is possible that radiator is clogged. Take hoses off and try to flush in reverse direction with garden hose and rag stuffed in bottom outlet.

Is the feed into the rad at the top of the driver side? Is there a petcock to let the coolant out on the passenger lower? It has a bunch of plastic stuff in the way and I can't see anything? The whole hot on one side and freezing on the other side has me wondering for sure. Thanks for the info

Could the cap be bad? It won't overheat at all when the cap is off?

Purpose of cap is to hold pressure, up to say 20 PSI, then vent before hoses pop. With no cap and just water will boil at 212. With 50:50 coolant mix, that rises to 234. With cap, maybe 265. Here's the plumbing layout, no drain petcock, have to take hose loose.

Be very careful around part 13, or you'll crack the stub and need a new radiator. Bad radiators get full of gunk from dexcool and failure to always use distilled water. Worst water is country well water, lots of lime. Usually blocks lower tubes first, so bottom feels way cooler than top.

Not seeing the steps. Got pix of a cruddy radiator though. Thanks.

Well I reverse flushed the rad and it flowed out the top an bottom within seconds and was clean. I flushed thru the waterpump also and it was fine. The thermostat looked like it was blocked off a little by the other part of the stat. Not the part I opened up which is the main part in the main body. I think I'm gonna get a replacement stat and refill it and see what it does.

Any more help would be appreciated. My main question is since the water flowed freely thru the radiator why would the driver top of the RAd feel super hot an the top passenger be cold. Cold as in not warm even a little. Does this indicate a rad issue. Just because it had flow when I reverse flushed it doesn't mean it's working properly I wouldn't think. I'm also not thinking the electric fan is working. What kicks the fan on? Thanks for any info. Kevin

The ECU is supposed to turn fan on at 212F. Earlier if AC is working. Fan has separate fuse, sometimes more burns out. Water flow freely means one thing to us, might appear different to indy rad shop. My shop guy says good condition radiator would be about 10F difference to to bottom. Water pump has a spec flow rate of 2.6 gallons per minute at 1000 rpm at 10 PSI. So if you can fill a five gallon pail in two minutes that is good. If it is a slow steam, not so good. Rad is like $200 up.

Well I put a new stat in it and burped the system properly. Wouldn't overheat at idle. Drove it and it started to overheat. Pulled over and the radiator looked weird. Like it was 2 different colors. I touched the top drivers side and it was scolding hot. Top left was freezing like the water I just put in it. The bottom left hose was freezing cold. Not warm at all. I think the waterpump is working because the fluid in the system is hot. The hot radiator stopped about 10in from the top hose then went freezing. Surely this is a radiator issue. Lmk what u think. Thanks kevin