OK - I've been trawling through all of the posts here, done keyword searches etc so I apologise if this has already been dealt with elsewhere.

As some would know from my other posts I've had (having still?) some cooling system issues.. Started with an over temp excursion one day coming home. No coolant, hot - waited for it to cool, topped up with water (all I could get) and got it home. Found it still had the red coolant in it, so I drained as best I could then flushed afterwards all of that out (kept on running clean water through it till there was no colour in the water anymore).

I found signs of a leak from under the throttle body - being in Australia I've looped that out of the system for now (cleaned the throttle body while it was out too) and I've replaced the return line from the radiator to the coolant bottle.

I have replaced the thermostat as the old one was totally stuffed.

Checked the viscous fan, feels like "peanut butter" to quote someones description here on another post) when you start to spin it, then once you get some speed up it then freewheels at least 304 turns before slowing.

The system is intermittently losing water - but no obvious leaks anymore.

I haven't yet been able to get a pressure test done (hope to get that done Tuesday - Holiday here Monday). BUT - this morning I thought I'd just take off the top radiator hose to help with spinning the fan, and the coolant was under pressure even after sitting cold all night... I also noticed after doing the bleed thing again and then starting the engine up that there was no coolant going through the return line to the coolant bottle (clear hose helps see that), but rather the coolant slowly migrated from the bottle to the radiator.

Any thoughts as to what could be creating / maintaining that pressure in the system?

 

Sounds like a leaking head gasket, it is letting combustion gases into the cooling system and pressurizing it, that would also explain the loss of coolant with no signs of a leak.
You can get a test kit to check for exhaust in the coolant.

 

Damn.... I have been suspecting all along that it could be, but haven't wanted to face that reality - mainly due to both cost and vehicle downtime at the moment. I'll get a mech workshop to check it out and see how much the damage is likely to be. I didn't want to be pulling the heads off without getting some nice ones that breathed a little better to put back on....

Cheers,

M.

 

Stuffed stat and freewheeling fan clutch did not do the HGs any favors. The chemical test Spike talks about will do maybe 15 tests, so it will test before and after repairs. Here's a link, https://landroverforums.com/forum/di...=chemical+test. Alternative to your high dollar FX test gear. Coolant loss could also be while driving and evaporates on something before you see it.

 

I think the fans ok - I just re-read my post and its meant to be 3-4 turns not 304, from what I have read it seems to work ok in that its gooey to start with until it has done a few turns then it "loosens" up, not entirely, but noticeably (looking at RAVE it could be at the 20% it suggests).

I've gone looking for the test strips at the auto shops here - no one knows about them, or I've been asking for the wrong things. Another one of the penalties of living here is that we typically have 5% of what the rest of the world can get and we pay at least 50% more for it.

I'll get a shop to do the pressure test etc and report back!!

 

If your fan spins more than one revolution hot from release then it is in need of replacement. Your comment about the water flow into the radiator from the bottle.... that could be some circulation taking place from bottle thru small hose, back thru big hose to T, down thru T to main thermostat, thru thermostat meter holes, and back to water pump. When main stat is closed, the small holes in the bypass disk callow flow into the thermostat chamber. When revved up cold, the bypass disk is supposed to move and allow water pump pressure to not go thru heater core 100%. Meanwhile, main stat is closed and no water flow out of radiator bottom hose.

 

Hey Savannah, the motor was cold when I was spinning it this morning and got the 3-4 turns... I'll try it hot tomorrow and see what it does!

Once I get this thing pressure tested I'll let you know the outcome too!..

Michael.

 

Bet it will be worse hot. These viscous drives work by having two grooved plates facing each other, and a fluid inbetween to provide the coupling. Pool fluid to one side overnight, and it will couple and provide the "fan roar" in the morning start up. Spin fluid around to spread, and heat slightly, fluid contact decouples from say 70% to about 20%, power used reduces on water pump and engine. If faceplate of spinning disks gets to about 170F, the fluid begins to re-couple to higher power level.

But is fluid level is low, because lost through the seal, which can make front of clutch look greasy (so it maches the rest of the engine bay); then all this design falls apart.

 

Soooo - took the disco into the shop today to get a professional opinion on my lil issue here. Turns out its the head gaskets.... Quoted me so far "worst case" just under 4k for c/o heads, that is of course if nothing else is wrong. Told me that last time, they pulled the heads off and ended up putting in a changeover motor - 6k for the motor change over plus the time taken to strip the old one down initially.

So, now on the hunt for nice heads... if I'm gonna get this thing stripped down I want to make it worth my while. Then, need to make the decision as to whether I do the job myself or not.

 

Here in the States, the set of head gasket parts and new bolts (they are stretch type, but you can also go back with studs) is about $300. An indy machine shop will machine the heads, usually for $200 or less. In the overhaul manual you'll find the step by step, the head spec for flatness is .002 inch, your printer paper is about .0038 inch. Many DIY write ups on this forum, average seems to be two weekends, with shop in between. Most indy shops around here are about 12 hours of shop time, so $1500 - $1700 US.

If you DIY, and machine shop says heads can't be machined (perhaps cracked) then go find heads used. You'll already know how to get them off at a salvage yard.

HGs are a pretty common repair. Less common is cracked block, slipped sleeves, all that fun stuff.