enjoi said:
What's worse, getting the dash apart to reach the heater matrix, or doing a head gasket? :stars:
Click to expand...
Both are fairly easy on a P38, but IMHO the dash is less work. Leaks usually stop the coolant pressurising, but also allow it to boil, so eventually there will be excess pressure.

As you've founbd one leak, do a coolant pressure test with the engine warm but off. Much easier to find hidden leaks that way.
 
Never had the dash out but even the thought overwhelms me. Much rather do a HG.
Where hoses connect to are usually corroded or covered in junk.. they need cleaning up properly to get a good, lasting seal. Also jubilee clips are ready to make a mess with because they don't stay round, meaning there will be a weak spot
 
kermit_rr said:
Never had the dash out but even the thought overwhelms me. Much rather do a HG.
Where hoses connect to are usually corroded or covered in junk.. they need cleaning up properly to get a good, lasting seal. Also jubilee clips are ready to make a mess with because they don't stay round, meaning there will be a weak spot
Click to expand...
There shouldn't be any Jubilee clips. The fixings should all be self-clamping spring hose clips that apply an even pressure. They are much easier to remove & replace than jubilee clips too just need to get them on & off with a pair of Flexible Wire Long Reach Hose Clamp Pliers
 
So I got that heater hose off and it looks like the pipes are just fine :banana:
As I was wrestling with the hose, I could see coolant seeping out of it- it was split. Looks like whoever replaced it last just use a regular hose which was too small. The correct hose should be slightly flared at the heater-matrix end.

By some miracle I was able to find the correct hose at some wholesaler that was only 15 minutes from my house, otherwise it was going to cost me over $100 Aussie dollarydoos to get it imported from the UK :vb-groan2:

This is what I got https://www.ebay.co.uk/itm/335376708715 (PCH118830) it says hose-heater-out, I need the heater in, but it was the same part number for both out and in so... /shrug


In other news, I got under the car at night with a UV torch to try track down the other leak, and turns out it doesn't seem to be coming from the radiator after all. But rather, something dripping onto the bottom of it somehow. I couldn't definitively tell where another leak was, but I could see a bit of dried coolant on the lower part of the hose that goes from the thermostat to the water pump. So perhaps that might need replacing as well.
 
Bit of an update:
Did a couple of test drives, around 20-30 minutes each. No more leaking from the heater inlet, but there was in fact a very slight leak from the bottom of the radiator- seems I was wrong in my previous post as I could clearly tell it was from the rad.
Seems the car had to be pretty warm for this leak to appear as I could only see it at the end of the longest drive of the day.

Fast forward to the weekend and I headed off for a camp in the bush. 40 minute drive to first pit stop, very slight leak from rad, nothing major. Next leg of the journey was probably about 30 minutes, but mostly up hill, but some pretty decent gradients and here's where things get interesting. During one of the hills the Rover went super weak and spongy, I'd put my foot down, but all I got was viscous fan roar and minimal power. This isn't new (https://www.landyzone.co.uk/land-rover/down-on-power-when-warmed-up.390199/) but this problem hadn't surfaced for a while now.

We got to the top of the hills and to the start of the trail and yep...

449526564_491964316627160_4516395279421215968_n.jpg

Queue the on-road repairs :vb-doh:
449378617_502336142252148_500236371794604428_n.jpg


The new heater inlet hose was leaking, so tightened it up. Also where the heater return hose meets the expansion tank hose had a leak, which was new. And the rad was leaking more than just a bit.

Thankfully it was all downhill to the campsite so made it there fine.

The next day, we got out the bush fine- probably because the uphill to get out was done while the car was cold. Then the drive home was fine, also mostly downhill- not a single leak to be found from the 1.5hr drive.

Not sure what to take from this. Maybe all the load going up hill expanded something in the head gasket and it overpressurized? Loss of power related to this?
 
enjoi said:
Bit of an update:
Did a couple of test drives, around 20-30 minutes each. No more leaking from the heater inlet, but there was in fact a very slight leak from the bottom of the radiator- seems I was wrong in my previous post as I could clearly tell it was from the rad.
Seems the car had to be pretty warm for this leak to appear as I could only see it at the end of the longest drive of the day.

Fast forward to the weekend and I headed off for a camp in the bush. 40 minute drive to first pit stop, very slight leak from rad, nothing major. Next leg of the journey was probably about 30 minutes, but mostly up hill, but some pretty decent gradients and here's where things get interesting. During one of the hills the Rover went super weak and spongy, I'd put my foot down, but all I got was viscous fan roar and minimal power. This isn't new (https://www.landyzone.co.uk/land-rover/down-on-power-when-warmed-up.390199/) but this problem hadn't surfaced for a while now.

We got to the top of the hills and to the start of the trail and yep...

View attachment 321033
Queue the on-road repairs :vb-doh:
View attachment 321034

The new heater inlet hose was leaking, so tightened it up. Also where the heater return hose meets the expansion tank hose had a leak, which was new. And the rad was leaking more than just a bit.

Thankfully it was all downhill to the campsite so made it there fine.

The next day, we got out the bush fine- probably because the uphill to get out was done while the car was cold. Then the drive home was fine, also mostly downhill- not a single leak to be found from the 1.5hr drive.

Not sure what to take from this. Maybe all the load going up hill expanded something in the head gasket and it overpressurized? Loss of power related to this?
Click to expand...
Loss of power will be the ECU putting it into limp mode to protect the engine. Leaks can cause overheating due to loss of the normal pressure required to stop the coolant boiling. I have never known a RAD that just leaks a bit when hot but you never know, RAD's generally just let go if over pressurised.
 
It does sound like it is pressurising.

I might be tempted to take the expansion cap off and then remove the spark plugs one by one and pressurise using an airline but keep an eye on the water level in the expansion tank.
 
Could just be poor sealing on pipes, due to rust/corrosion etc. Pressure will rise rapidly as the coolant gets closer to boiling. Thermostat isn't fully open until 96c and you'll see this reached while going up hill etc
 
Grrrrrr said:
It does sound like it is pressurising.

I might be tempted to take the expansion cap off and then remove the spark plugs one by one and pressurise using an airline but keep an eye on the water level in the expansion tank.
Click to expand...
You'd have to do this when the engine is fully hot
 
kermit_rr said:
Could just be poor sealing on pipes, due to rust/corrosion etc. Pressure will rise rapidly as the coolant gets closer to boiling. Thermostat isn't fully open until 96c and you'll see this reached while going up hill etc
Click to expand...

As you say, could be all sorts of things. I'm a little worried the rad might be pushing the caps off enough to weep when hot though. Best exclude that possibility if it is easy (cheap) to do so.
 
Datatek said:
Loss of power will be the ECU putting it into limp mode to protect the engine. Leaks can cause overheating due to loss of the normal pressure required to stop the coolant boiling. I have never known a RAD that just leaks a bit when hot but you never know, RAD's generally just let go if over pressurised.
Click to expand...
I had my OBD reader on and the coolant temp didn’t get too high, unless that sensor is cooked, or maybe it got really hot in a localised area.
The hills and loss of power started around 1:20

IMG_3178.jpeg


Agreed about the rad, once it started leaking I thought that’d be it. /shrug
 
Grrrrrr said:
As you say, could be all sorts of things. I'm a little worried the rad might be pushing the caps off enough to weep when hot though. Best exclude that possibility if it is easy (cheap) to do so.
Click to expand...
I put a new expansion tank on and it was easy to overtighten the cap, at which point it would pop the thread and lose pressure
 
I’ve done the expansion tank and cap dance before. I replaced the tank probably a year and a half ago, along with the cap as they were both warped.
I reckon my current cap is on its way out. It still tightens fully, but the thread feels a little weird.
 
enjoi said:
I’ve done the expansion tank and cap dance before. I replaced the tank probably a year and a half ago, along with the cap as they were both warped.
I reckon my current cap is on its way out. It still tightens fully, but the thread feels a little weird.
Click to expand...
yes its the thread i had issues with as well. the cap would screw on to the old (original) tank no problems, but it was easy to cross thread on the britpart tank. i think the thread must be slightly smaller than OEM which is why it would pop off if tightened too much
 
enjoi said:
I had my OBD reader on and the coolant temp didn’t get too high, unless that sensor is cooked, or maybe it got really hot in a localised area.
The hills and loss of power started around 1:20

View attachment 321040

Agreed about the rad, once it started leaking I thought that’d be it. /shrug
Click to expand...
I don't know about the V8, but on the diesel there are 2 coolant temperature sensors, one for the gauge and the other for the ECU.
 
Based on the thread title, how many radiators have you gone through ?? What brand ??

@Datatek There's two sensors on GEMS, but one dual sensor on Thor.
 
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