Blown coolant hose, 95 Disco V8

[procrastination inc]

Towing a big car trailer packed with a kitchen for the shed today, I was giving the poor thing a bit of stick heading up the hill to Koetong. (2nd on the Auto 4000revs foot to the floor)

I watch the temp gauge climb steadily to 3/4 up the "normal" band on the gauge. It usually sits in the bottom quarter. It settled there, but I was still a bit worried, so I thought I'd switch to petrol as it burns cooler. A couple of seconds after I switched, I saw a big puff in the rear view but no cough from the engine ??

Then I saw the temp gauge dive for cool... ****! Pull over.

Had my co-pilot pop the bonnet as I got out. Steam every where and a bad Tick Tick Tick, sounded like a sticky lifter.

Shut down the engine.

No water on board (it has never used a drop in 5 months)

A Dad and a couple of kids pulled up and managed to fetch some water from a couple of km up the road.

Filled the radiator, took about 6 litres. as we did, we spotted the fault. Stumpy little hose that connects the manifold/thermostat housing to the solid heater line mounted on the rocket cover had split underneath.

Now, this hose is about 3" long. 3/4" ID one end and 7/8" the other. I can see no good reason why it couldn't be 3/4" both ends and you could just cut and shut the heater hose to suit. As it was, I was stuck... until I spotted the crank case breather hose.

This hose is spread over the baffle cap at about 7/8ths, the other end near the plenum is 3/4" :) hook this into the heater line, Plug up the loose manifold ends. It doesn't have any braiding, so I was worried about the pressure. I left the coolant expansion bottle cap loose (This was a bad move)

All started ok, no odd noises or leaks off we go.

Stopped after a few Kms , all good. Another 10 Km, all good. about 30km after that the temp gauge climbed again. Pull over, low coolant. Filled it up again, but screwed the lid on tight. Drove home 120km, towing trailer, checking regularly but with no more problems.

Got home, checked the oil, no mayonnaise. Only new external leak I spotted was on the valley seal just above the water pump. I wonder if this was always there, but without the vacuum on the crankcase breather the higher pressures make it noticeable.

Now for the questions :)

I am worried about engine damage. I thought I caught it pretty quick, but the TICK TICK TICK has me worried. What do I need to watch out for?

WTF did LR decide to put a 7/8" hose tail fitting in the manifold where a 3/4" hose meets it? The little adapter hose was only $10, but it unnecessarily complicated field repairs >:{. Has anyone modded their manifold fitting to accept straight 3/4" hose?

[Slunnie]

the reason the cap pressurises the cooling system, is it raises the boiling point of the coolant. Water will rise from about 100 to 115 degrees, and with a good mix of coolant it will raise again to about 125 - 130 degrees. The normal operating temp of the motor is over 100 degrees in the coolant.

Anyway, it's good that you made it home at least.

[procrastination inc]

Yeah, I know. I was tossing up between pressurising the non standard hose, blowing it and being really stuck, or leave the system open to unload the hose, but boiling off the water.

In the end, I got jack of stopping to top up water...

Pray for my alloy block engine :(

[markd2]

hi pro

don't think you have done too much damage to engine but that hose has been a problem for me too I found out you can get the same hose 3/4 - 7/8(its a heater hose only longer) from supercheap or any parts supplier for a EF falcon 4.0 litre engine I kept one as a spare after my wife destroyed an engine in my D1 18 months ago every expensive lessen

[procrastination inc]

I'm thinking I should get a wreck and start rebuilding an engine. Nice High compression one for gas :)

[PLR]

All started ok, no odd noises or leaks off we go.


Now for the questions :)

I am worried about engine damage. I thought I caught it pretty quick, but the TICK TICK TICK has me worried. What do I need to watch out for?




G`day ,

only suggesting and not questions to answer but to ask yourself .

Tick tick was coz the oil got hotter/thinner than it liked which of coarse means so did the engine ? Or the thinning of the oil is just showing your lifters/cam have some wear ?

It would probably pay to go over the engine and nip up anything with a gasket under it or wait and see if new leaks occur .


When you changed over to petrol , more so if it was under load , at some time only short time but neither fuel is flowing and a lean condition occurs . If it`s already hot that leaning makes it hotter still .

Since it seems like you saw when the hose blew , next to consider is why .
It was just the extra load on the engine which raised the coolant temp enough to find the weakest point ?

How old was the hose and why didn`t the cap release the pressure at the prescribed 15 or so psi ?

When a head gasket starts to leak it will normally do it or is noticed that it is doing it when under load like towing or just climbing .

Gauge rises as does the pressure in the coolant system .

These engines because of their design don`t show with oil in water or water in oil as is the norm with head and/or gasket problems and they don`t crack heads because of their design if standard .

So i`d suggest if the gauge starts to sit higher than normal , see if you have pressure and/or bubbles in the system .

If nothing out of the ordinary happens , replace the hoses and forget it happened ( if you can https://www.aulro.com/afvb/images/imported/2015/12/13.jpg )

Cheers

[RonMcGr]

I doubt you have done any damage at all.
It was all too quick.
What does surprise me is the temperature gauge!

My Disco never moves any further than one third up the dial and I tow a Caravan with it. Many big hills are taken in lower gears nut I never push it beyound 3,500 RPM.
Most times we have the air con on, so the front electric fans are working, although on steep hills I can hear the large engine fan cut in. It makes a hell of a roar.

Just wondering if your fan hub is working?

[procrastination inc]

Thanks for the replys

.....Tick tick was coz the oil got hotter/thinner than it liked which of coarse means so did the engine ? Or the thinning of the oil is just showing your lifters/cam have some wear ?...

Maybe, I think I like that answer.

It would probably pay to go over the engine and nip up anything with a gasket under it or wait and see if new leaks occur ....

I'd better wash it again too, I'd struggle to spot much:angel:


When you changed over to petrol , more so if it was under load , at some time only short time but neither fuel is flowing and a lean condition occurs . If it`s already hot that leaning makes it hotter still....

I always switch over with accelerator all the way off.

Since it seems like you saw when the hose blew , next to consider is why .
It was just the extra load on the engine which raised the coolant temp enough to find the weakest point ?...

My guess, oldest hose. All the heater hoses bar this one had been changed when the gas went on. Lower radiator hose is after market. Had it blown before and the motor has suffered in the past? :confused:

why didn`t the cap release the pressure at the prescribed 15 or so psi ?

Dunno maybe it popped at less than the cap pressure? It was pretty soft

My Disco never moves any further than one third up the dial and I tow a Caravan with it. Many big hills are taken in lower gears nut I never push it beyound 3,500 RPM.
Most times we have the air con on, so the front electric fans are working, although on steep hills I can hear the large engine fan cut in. It makes a hell of a roar.

Just wondering if your fan hub is working?

How do I check that?

I wonder if I might be a bit lean on gas?

[RonMcGr]

As for the fan hub, when you start your car in the morning, does the fan roar for a minute or so and then stop?

That is what it do if they were quite warm when switched off the night or day before. The noise the fan makes when the bi-metal switch activates, is the same.

If you get none of that, you may well have a faulty viscous hub.

Cheers,
Ron

[procrastination inc]

Yes, it does. Roars for about 100m meters from my place when I start in the mornings, the goes quiet. So that is probably ok?

[RonMcGr]

Yes, it does. Roars for about 100m meters from my place when I start in the mornings, the goes quiet. So that is probably ok?

In that case, yes it should be fine.
Just keep an ear out for the roaring noise when the temp gauge gets closer to half way.

Cheers,
Ron

[tempestv8]

I would think that you should totally overhaul the cooling system. New water pump, thermostat and definitely new radiator because the existing radiator may be blocked to the point where there's not much cooling capacity reserve.

The Rover V8 really doesn't like overheating. Mine never overheated yet managed to suffer a slipped cylinder liner. Grr!!! :mad:

[procrastination inc]

Well, that roar in the mornings isn't there any more. Guess the fan hub is stuffed.

Are these rebuildable?

switched on the aircon on the way home. Temp went up to 2/3rd of the middle range :(

[RonMcGr]

Well, that roar in the mornings isn't there any more. Guess the fan hub is stuffed.

Are these rebuildable?

switched on the aircon on the way home. Temp went up to 2/3rd of the middle range :(

I don't know if they are.

When you turn on the air con, do the twin front electric fan start?

Ron

[procrastination inc]

Yep. they also kick in when the temp gauge is over 1/3 of the normal range, even when the air con is off

[procrastination inc]

LAND ROVER VISCOUS COUPLING-L/ROVER DEF-DISCO V8 - eBay Media, Cars, Trucks, Clothing, Merchandise, Media, Cars, Bikes, Boats. (end time 07-Apr-08 09:35:12 AEST) (http://cgi.ebay.com.au/LAND-ROVER-VISCOUS-COUPLING-L-ROVER-DEF-DISCO-V8_W0QQitemZ200212275919QQihZ010QQcategoryZ125952Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem)

ouch

[RonMcGr]

Yep. they also kick in when the temp gauge is over 1/3 of the normal range, even when the air con is off

Okay, Then I suggest you do what tempestV8 said.
There is obviously something wrong with your cooling system.

My 97 V8, never gets hot, even towing on stinking hot days.

I think you should remove the radiator and take it to a Radiator shop to be "reconditioned" I think you have poor circulation. Flush the engine block, refit the radiator and you may well be surprised :D

$150 for a hub is not too bad. I tried to by a Jaguar one and found it was cheaper to fit the AU/BA Ford twin electrics, which I did, at $280.

Way back in the 80's I was quoted $150 for a Mercedes Benz one. :eek:
Make a few calls, but I think you may find that is "not bad".

Cheers,
Ron

[procrastination inc]

thanks ron

[procrastination inc]

new hub is in the mail.

thought I'd replace the thermostat too

Bottom bolt on the housing is well rusted in and the head sheared off when I tried to undo it :mad:

left 10mm hanging out but in a pretty awkward position. Got onto it with visegrips, whacked it on the head a bit and and loaded it with WD40 to no avail.
I think easy outs will be a one way ticket to hell on this one. Might need to buy a stud extractor.

I wish I had some heating method to warm up the alloy. WIP...

While the WD40 was soaking, I thought I'd check the old thermostat. Didn't open in a boiling pot...:eek:

[tempestv8]

Procrastination,

Sorry to hear about this head shearing off.... but what exactly are you referring to? Is this the water pump housing that you're talking about?

BTW the LR viscous coupling is fully sealed, so it's not refillable like some Toyota ones are. So if it's stuffed, just get a new one.

Sounds like your thermostat is stuffed as well.

One thing that I do know about LR thermostats - they tend to fail in the "open" position, so the engine will run cold instead. They don't often fail in the "closed" position from age, but often due to being overheated. So I think that whilst you will need to replace your thermostat, it's not the root cause of your overheating problem in the first place.

I'd get the radiator replaced or recored, whichever is cheaper.

Lawrance

p.s. re the stuck stud, try Loctite Freeze & Release?

Loctite-MRO Promotions (http://www.loctite.com.au/int_henkel/loctite_au/index.cfm?pageid=127)

[procrastination inc]

Thanks guys for your info.

I was thinking that the root cause of my over heat was the dead thermostat.
But I'm not so convinced now.

I need to take out the radiator to get my drill in to take out the thermostat bolt, so I'll take it to a radiator specialist to have it checked out.

The viscous coupling has not arrived yet. Luckily, I don't need the car until next thursday

[Tombie]

Mate...

When I had the Stroked 3.9 it did this to me twice :(

That little hose always plays up.. In the end I carried a spare in the area below the windscreen (a good spot for all spare hoses and belts)...

Last time it did it was in the middle of the South Aust outback at 12.30 in the morning on a road in the middle of nowhere... No spare hose then...

Lots of duck tape and a few zip ties... Got me limping into a town for the night (3 hours later)...

I'd definitely say... Get the radiator rodded... Replace the thermostat and you'll be fine...

If the viscous is U/S get another one as well...

[procrastination inc]

That little hose being a special peeves me a bit.

I have a Stainless Steel 5/8" hose tail that looks to have the same thread on it as the 3/4" one on the manifold. This would let me run straight 5/8" hose there, same as the rest of the heater hose. Modularity of spares is a great thing.

My only concern with this is a vague memory about galvanic corrosion issues with SS/Aluminium joints. Anyone got info on this?

[PAT303]

One cheap and easy way with the fan is fit an early ford six fan.I bought one for $20 from a wrecker once when mine died and it screwed straight on.It even roared for the first minute like the original.One thing to is they pump more air so they could be a good thing for towing. Pat

[procrastination inc]

NOW you tell me... :)

[PAT303]

Sorry mate I thought everyone new that one. Pat

[procrastination inc]

Well, I didn't take the radiator out.

Bought a little pneumatic drill that was short enough to get in. Drilled the guts out of the broken bolt, picked the remaining spiral out and ran a tap up to finish it. Slightly off centre with the drill, so a little truncating of the thread. I think the Whitworth standard allows something stupid like 30% so I'm not too stressed about that.

I'll get prices on rodding my radiator and do it at my leisure

[Tombie]

Well, I didn't take the radiator out.

Bought a little pneumatic drill that was short enough to get in. Drilled the guts out of the broken bolt, picked the remaining spiral out and ran a tap up to finish it. Slightly off centre with the drill, so a little truncating of the thread. I think the Whitworth standard allows something stupid like 30% so I'm not too stressed about that.

I'll get prices on rodding my radiator and do it at my leisure

BSW thread on a 3.9 block? I was surprised to hear that......:eek:

[procrastination inc]

manifold, thermostat cover bolts.

Ran a 5/16" BSW nut straight up the good one that came out. so It seemed good to me. You reckon they might be M8?