Puma 2.4 losing coolant

[swivelrat]

Hi all,
Small problem this morning towing heavy trailer, motor lost power, pulled over, temp still normal but coolant puddle under car. Got home ok but needed a couple of litres to top up tank. Can't find where it's coming from. Pressurised the tank and no leaks. Most coolant is under driver's seat, thought it was the expansion tank but holds pressure at 10psi. Maybe radiator cap? Cheers

[DazzaTD5]

pressurize to 16psi, you need to simply keep looking.

common items, but most are passenger side;
heater valve, passenger side.
water pump, passenger side.
engine oil cooler (what the oil filter attaches) plastic fitting underside, passenger side.
most of the cooling hoses are also passenger side.

expansion tank cap, drivers side.
egr cooler hoses, one is by the expansion tank.

[swivelrat]

Thanks DazzaTD5, looked at all the usual culprits, found that the cap was faulty, new cap seems to be retaining coolant now but coolant temps still fluctuating using Gap IId unit to phone. Its usually pretty stable around 88-90deg sometimes ups with head temp under loads. I'll change the thermostat while Im dropping coolant to change oring in oil cooler and I'll disconnect all plumbing of water to the unit before the EGR as its all disconnected anyway.
What do you think to the engine power dropping off, is this a engine saving mode or did the pistons grab with extra heat?? It recovered in seconds and pulled at usual power. It's not using oil, still got plenty of power on hills under load (towing 1500kg), no oil or bubbling in water or water in oil. guessing head is still ok or is it.

[spudfan]

The engine is designed to stop if the temperature reaches a certain point. It will start again when the temperature drops. Happened to our 2.4. Culprit turned out to be a faulty hose clip passenger side. Coolant was escaping.

[MLD]

the safety feature for coolant temp is pretty high, like 115 deg C. It's not uncommon for the coolant temps to get north of 100 deg C under sustained load (long hill). so long as the temps drop relatively quick once the load abates, its considered normal. 3 summers ago i drove across the Hay Plain and the temp never dropped below 100 deg C for hours on end, no adverse effects. The Puma head is pretty resiliant to high temps. I only know of 1 Puma engine that cracked a head and that was towing a heavy caravan on a really hot day. Keep driving like normal and if you start losing coolant or abnormal high or sustained temps would you consider a long term problem.

[DazzaTD5]

Thanks DazzaTD5, looked at all the usual culprits, found that the cap was faulty, new cap seems to be retaining coolant now but coolant temps still fluctuating using Gap IId unit to phone. Its usually pretty stable around 88-90deg sometimes ups with head temp under loads. I'll change the thermostat while Im dropping coolant to change oring in oil cooler and I'll disconnect all plumbing of water to the unit before the EGR as its all disconnected anyway.
What do you think to the engine power dropping off, is this a engine saving mode or did the pistons grab with extra heat?? It recovered in seconds and pulled at usual power. It's not using oil, still got plenty of power on hills under load (towing 1500kg), no oil or bubbling in water or water in oil. guessing head is still ok or is it.

Items that help a TDCi with regards to the cooling system include changing:
*Thermostat, go to a 82 deg C (normally grey in colour but this is NOT a given)
*change water pump.
*change heater valve (if its leaking or dis-coloured)
*change viscous fan, these simple wear out.
*ensure radiator is clean inside and not blocked on the lower part

[DazzaTD5]

The issue with getting a Defender TDCi hot or too hot is not so much the head cracks but it goes soft beyond use.
its a given if one turns up after an over heating issue is to quote to replace.

The positive side is all new heads (and complete engines) I get come out of Ford's South Africa plant and seem very nicely finished as opposed to Fords other plants that seem to have a lack of finish.

[swivelrat]

Thanks for the advice Dazz, whats a SA head worth to replace out of interest, north of $5k? Hoping Im not ready for one yet after todays adventures.

Well, pressurised to 16psi last night, didnt move for 15mins, seems ok but was cold so probably wouldnt indicate a crack in the head that opens on temp. Good thing is that there was no coolant leaks anywhere obvious.
Took for a run this morning, head temps still getting up there but not excessive, coolant temp was all over the place. So I suspected that thermostat is done but was confirmed as bottom hose was cold on return from run. Will replace shortly and hopefully I'll be back in business towing excessive loads in excessive heat tomorrow with no head issues fingers crossed. :firedevil:

[swivelrat]

Well, looks like the thermostat was fine, but still blowing coolant out the cap on load, temp gauge still showing normal, GAP II live values for coolant temp climbs to 110deg and head temps north of those. Anyone had hassles with water pump? Surely if spinning on the outside, that the water pump is spinning inside?? There is plenty of coolant coming out of bleed valve on idle which would indicate coolant flow??

Guessing a new head gasket otherwise, head at the worst unless there are any other obvious leads?

Thoughts.

Cheers all.

[DazzaTD5]

You or your mechanic can take a chance and just do the head gasket, but I have my doubts. I mean hey a decent mechanic should be able to take a educated guess.

The last two i decided just to do a head gasket was still suffering the same over pressurising the cooling system, which means doing it all again.
A note on that, doing it again is on me, as the final decision is me making that call. I have seen plenty that say, that its on the customer to pay again for labour as they gave the go ahead.
Hardness test will show if its close to the min hardness, if its close ditch it.

cost:
$5K for the head and all the bits needed. (includes timing chain and related parts).
$3K labour (i did do other items while I was there).

I think the above costs are a reasonable ball park figure.

[swivelrat]

Thanks again Dazza, I think it'll be a new head myself but will firstly do a test for exhaust gases in the expansion tank and I'll try doing a vacuum coolant fill rather from the top. Im still hopeful that the over-pressurising is from a coolant air lock somewhere. Bottom hose is still cold so I dunno. It's a genuine new thermostat though I dont know if it opens at 82 or 88.
cheers

[DazzaTD5]

Its very common on these engine that no hydrocarbons show up on a chemical test.
Its not a complicated cooling system, i have never vac filled them.

you could change out the water pump and thermostat first as a test.