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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
2.4 heater hot then cold
Heater has started today blowing between hot and cold when the vehicle is being driven at any coolant temp up to normal coolant temp. coolant temp not fluctuating staying horizontal once warmed up.

Just before it blows cold it gets very hot.

i am assuming air lock or similar in heater pipes but thought i would ask here before i start looking around in case anyone has already had similar and fixed it.

edit to add: coolant was a little low about 1" below the cold line, its normally 1/2" below the line. topped it up and bled from heater hose elbow. still seems to do the same.

Was there a post about the header caps failing? Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #807885 28th Dec 2019 5:40pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
since above i have beld the coolant system and replaced the coolant res cap.

no change.

other observations from driving today are below with heater on full heat and fan on position 1, flow direct 50/50 handbrake/screen

1. heater cools within 6-8 seconds of vehicle becoming stationary or less than 1500rpm driving.
2. increase to 2000rpm and within 8s heater is hot, sometimes too hot.
3. coolant level is constant or no noticable change in level over 200miles
4. expansion and stiffness in one of coolant pipes to/from thermostat which goes when coolant lid removed (engine running)
5. dash coolant temp needle moves at normal rate up to 'normal' horizontal position from cold and stays at horizontal position.
6. vehicle doesnt smell hot and coolant pipes all feel to be normal operating temp with exception of:
6.1 when heater is cold the small heater mixer pipe closest to engine is also cold.
7. at idle engine running at operating temp the rad return pipe to the expansion bottle has a flow that is interrupted with air.

grateful for opinions please. Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #808745 4th Jan 2020 6:43pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
ok did a bit of testing this eve once it had cooled down.

bypassed the egr cooler, noted at time no coolant in the top hose to the cooler.

refilled coolant and went for a drive.

some white smoke/steam on initial pulling away from exhaust - vehicle had been left idling 3mins. dark after that so i couldn't see if anymore smoke/steam was evident out of the exhaust.

heater initially working then went cold at low engine revs, increase revs it warms up.

expansion tank is pressurising and venting coolant whilst under load and continued to vent air through cap once stopped and turned off.

on releasing pressure without any further coolant loss at expansion tank, coolant level increased to just below the cap (it was filled to the fill line)

no coolant in the heater output pipework.

vehicle drives well @ 53k miles, pulls better than one of my remapped 2.4s (i think this one may have a map despite being told when bought last year that it didnt)

other tel tale to note is that the EGR cooler pipes (inlet and return ) have both had the LR pipe fitting replaced with jubilee clips so someone has been in there prior to me.

currently not looking great to me!

what to do next? Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #808772 4th Jan 2020 10:14pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
too add

rad bottom hose stone cold after above drive
engine coolant gauge sat at halfway

when vehicle was purchased i changed the thermostat as it was permanently open vehicle temp sat at 1/4 prior to changing this.

vehicle has performed faultlessly for last 4k miles of mixed driving and towing using no coolant. Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #808773 4th Jan 2020 10:24pm
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DAZ110



Member Since: 06 Dec 2007
Location: East Sussex
Posts: 2035

United Kingdom 2013 Defender 90 Puma 2.2 XS CSW Barolo Black
Try another thermostat ?
Post #808778 4th Jan 2020 10:38pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
thats my current thinking in that it cant hurt on the off chance its just not bleeding air through Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #808845 5th Jan 2020 3:54pm
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neon1991



Member Since: 26 Mar 2018
Location: Colchester
Posts: 75

United Kingdom 2014 Defender 110 Puma 2.4 USW Firenze Red
Did you ever get to the bottom of this. Mine is doing the same thing and doing my head in now
Post #951240 1st May 2022 5:41pm
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blackwolf



Member Since: 03 Nov 2009
Location: South West England
Posts: 17339

United Kingdom 2007 Defender 110 Puma 2.4 DCPU Stornoway Grey
Pumas will do this if the coolant level is a little bit low, so that is the first thing I would check.
Post #951260 1st May 2022 7:05pm
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neon1991



Member Since: 26 Mar 2018
Location: Colchester
Posts: 75

United Kingdom 2014 Defender 110 Puma 2.4 USW Firenze Red
Cheers,I’ve put a thread up in the puma section. Having similar issues. Level reads normal when cold and cap off. Problem I have is that it’s pressurising and holding pressure when cold.
Post #951263 1st May 2022 7:13pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8006

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
head gasket on mine Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #975083 18th Dec 2022 9:57pm
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neon1991



Member Since: 26 Mar 2018
Location: Colchester
Posts: 75

United Kingdom 2014 Defender 110 Puma 2.4 USW Firenze Red
Yeah, old thread but mine had a crack in the head. New engine in it now.
Post #975084 18th Dec 2022 10:02pm
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Bluericky



Member Since: 26 Jun 2014
Location: Cornwall
Posts: 647

United Kingdom 2009 Defender 110 Puma 2.4 DCPU Keswick Green
New engine ?
I've never looked into changing the head gasket on a TDCi but have changed them on a couple of 300TDi's and it didn't take too long.
Are the TDCI engines really that disposable or are the tolerances just too fine for the home mechanic ?

Reason I ask is that my 130 is driving faultlessly but I'm also suffering from coolant loss and pressurising of the system. If I take the lid off even 24 hrs after it's last been driven, I get a long hiss and lots of gurgling ! https://www.instagram.com/hustynminepark/
Post #975187 19th Dec 2022 9:49pm
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neon1991



Member Since: 26 Mar 2018
Location: Colchester
Posts: 75

United Kingdom 2014 Defender 110 Puma 2.4 USW Firenze Red
They’re not great engines but that’s my opinion. I needed mine on the road fairly quick so went to a a garage who said the labour cost of doing the head gasket is going to be the same as swapping the engine out. It was doing the same as yours but mine ended up being a crack in the block and not so much the head gasket. Don’t know if the engine had been cooked before but it ran perfectly for years and then all of a sudden, started to dribble coolant out of the header tank. This got progressively worse over a few weeks to the point that it was chuffing out it’s coolant at highrevs. There wasn’t a hint of smoke from the exhaust either. By the time you have taken the head off, you are practically left with just the block. Everything has to come off. It was easier for me just to swap it at that point.
Post #975203 20th Dec 2022 7:27am
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neon1991



Member Since: 26 Mar 2018
Location: Colchester
Posts: 75

United Kingdom 2014 Defender 110 Puma 2.4 USW Firenze Red
It’s not unknown for the egr cooler to get holes but if you have bypassed this and you are still getting pressure then you can fairly safely rule it out
Post #975204 20th Dec 2022 7:30am
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Bluericky



Member Since: 26 Jun 2014
Location: Cornwall
Posts: 647

United Kingdom 2009 Defender 110 Puma 2.4 DCPU Keswick Green
Great 🙄
Is there anyway of finding out if it’s a crack. Some sort of clever thermal imaging etc ?
Did you go new, refurbished or used low miler ? https://www.instagram.com/hustynminepark/
Post #975212 20th Dec 2022 8:51am
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