Thread: 2.2 Puma "overheating" Issue, speculation on cause invited

Your engine is overheating because of high EGT.
The standard gauge is **** and is only an indication.
By the time it moves you have overheated get one of these for real time monitoring.
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When coolant temp starts to rise back off and change down a gear.
They do not like hills in 6th gear I usually keep my revs above 2000rpm.
You can change the thermostat to a V8 petrol one with a lower opening temp.
Mark

Originally Posted by big harold

The standard gauge is **** and is only an indication.
Mark

Agree completely with this, I run an Ultra Gauge on my 2.2 with BAs intercooler and the 170HP tune and I have seen the water temp on the Ultra Gauge at 116C and the factory gauge hasn't moved, I hate to think how hot yours must have got if the factory gauge has moved. Mine normally runs around 89C but depending on driving conditions easily moves around up to 100C on hills and down to 82 coasting downhill.
Completely agree about 6th gear, they hate hills in this cog (and sometimes lower cogs depending on the hill).

This is a bit of a common occurrence with the Defender TDCi (2007 - 2016).
Simple answer as already suggested, select a lower gear, top gear really is a bit tall, keep revs 2200 or above.
also note that 100/105 isnt hot for a cooling system under pressure
engine protection is quite good and will do 2 reductions in performance before pushing the gauge to the top end of the scale

typically round that 200K some items may need doing or upgrading and will help with cooling.

*radiator
*water pump
*serpentine belt
*viscous fan (if a 2.4, fit a 2.2 viscous fan)
*lower thermostat 82 deg C
*decat/small cat.
*bigger intercooler.

Thank you for the input so far, I guess my question is how do I eliminate this behavior? An EGT gauge would be a good thing but it's only going to tell me that I should lift my right foot earlier than waiting for the engine management to limit fuel delivery.

Earlier opening thermostat is possibly a good idea. Maybe a different tune? Maybe a bigger radiator? Maybe a different exhaust? Anyone out there solved the root cause?

I suspect that I may be in the minority complaining about a problem that others haven't been motivated to investigate or fix given my set of circumstances ie +30 degree freeway running with a vehicle that isn't likely to be purchased for this purpose that doesn't include heavy loads where a lower gear is required because that solves the 6th gear problem.

Or do I just live with it and accept that a Defender was not designed to drive from Albury to Yass on a hot day at 110 km/h.

Edit, Thanks Dazza you replied while I was thinking Incidentally the vehicle has about 130,000 KM on it

Regards,
Tote

Originally Posted by Tote

Thank you for the input so far, I guess my question is how do I eliminate this behavior? An EGT gauge would be a good thing but it's only going to tell me that I should lift my right foot earlier than waiting for the engine management to limit fuel delivery.

Earlier opening thermostat is possibly a good idea. Maybe a different tune? Maybe a bigger radiator? Maybe a different exhaust? Anyone out there solved the root cause?

I suspect that I may be in the minority complaining about a problem that others haven't been motivated to investigate or fix given my set of circumstances ie +30 degree freeway running with a vehicle that isn't likely to be purchased for this purpose that doesn't include heavy loads where a lower gear is required because that solves the 6th gear problem.

Or do I just live with it and accept that a Defender was not designed to drive from Albury to Yass on a hot day at 110 km/h.

Edit, Thanks Dazza you replied while I was thinking

Regards,
Tote

As i mentioned its becoming quite a common thing....
*do my list
*lift your foot off the throttle pedal
*change back a gear, 2200 rpm and above.

Cause:
*its a diesel with respectable low down torque so rather than use gearing drivers tend to use the throttle.
*although its a 4 cylinder and not a long engine, it is a very wide engine with all the ancillaries on it so air flow through the somewhat square engine bay isnt that good.

2.4 Puma 130 - in the middle of summer crossing the Hay Plain my average coolant temps will be +/- 100C when during other times of the year it will be +/-90C. I run a scan gauge and ease off when the temps on long hills start to climb towards 100C. They rarely go above 105C if i ease off as described and drop quickly once i crest the hill and come out of the pedal.

What you describe doesn't sound like a systemic problem. You might be, as Dazza suggests, at a point of a refresh of the cooling system.

Originally Posted by MLD

2.4 Puma 130 - in the middle of summer crossing the Hay Plain my average coolant temps will be +/- 100C when during other times of the year it will be +/-90C. I run a scan gauge and ease off when the temps on long hills start to climb towards 100C. They rarely go above 105C if i ease off as described and drop quickly once i crest the hill and come out of the pedal.

What you describe doesn't sound like a systemic problem. You might be, as Dazza suggests, at a point of a refresh of the cooling system.

I'm not discounting your experience but I can drive on the flat with no consequences as well, its the hills that bring on the fuel limiting. The temp rapidly drops within 500 m of the crest of a hill as well. The vehicle has a new serpentine belt and a BAS intercooler so I'm some of the way there. Maybe the viscous fan is dropping off in its performance as I no longer get the belt squeal when hot. I have done some googling this morning and Allysport make a bigger radiator which might be worth investigating if it will fit in there with the BAS intercooler.
The thermostat is a no brainer and I'll do that as soon as I get round to it.

Regards,
Tote

Originally Posted by Tote

I'm after some educated opinions on the root cause and corrective actions for my 130's hot weather performance issues.

The Vehicle:
Stock 2016 2.2 Puma Defender 130 fitted with a BAS intercooler since the OEM one split. No tune or any other modifications.

The Symptoms:
On hot days long runs uphill will cause the temperature gauge to move from slightly under half where it usually runs to slightly over half a gauge. As this happens performance is reduced possibly due to EGT being over the programmed level. (I understand there is no actual EGT sensor in the stock management system) This is most evident on long hills at 110KM/H. The vehicle does not do it on days below 30 degrees or when towing a trailer at a slower speed. A/C also cuts out under the "overheating" condition

Some Background:
The vehicle used to have a slipping fanbelt on hot days with the A/C on, this was indicated by a persistent squeal that could be fixed by turning the AC off and/or slowing down. This symptom has not occurred since the new intercooler was fitted but this may be coincidental.
The clutch fan appears to still function normally but may not lock up as much as it once did, potentially contributing to both the lack of belt slip and the increase in temperature.

I have a GAP tool but haven't done any detailed diagnosis with it. I'm happy to take suggestions on what counters and readings are useful.

Regards,
Tote

Tote, i'll touch on what i know of the above and something that you might not have considered.

The effectiveness of a radiator is primarily dictated by the temperature variance between the ambient air and coolant temp. Larger the temp variance more effective the radiator is at transferring heat (same applies with intercoolers). On hot days, the radiator is not as effective, simple as that. Fitting a larger radiator, especially thicker radiator, does not necessarily improve effectiveness. Coolant at the front of the radiator gets exposed to the coolest ambient air, as air passes across the fins, it heats up reducing the heat transfer effectiveness. Thus the coolant at the back of the radiator might not be transferring heat or much heat. Contrary to the rationale my little brain can comprehend, the prevailing wisdom is speeding up coolant flow improves heat transfer efficiency. It sort of makes sense if you view it in the context that the coolant heats the ambient air and longer there is exposure, the hotter the air until effectiveness of heat transfer is diminished significantly.

AC in the Puma is a very simple set up (researched it for the LS and have pawed over the schematics). There is a trinary switch on the side of the blower motor. When you turn on the AC on the dash, it sends a +ve to the trinary switch. The trinary switch sends a +ve and -ve to the ECU. I haven't worked out what signal does what. The ECU sends a -ve 86 trigger signal to the AC compr and AC fan relays. As far as i can tell from the schematic, ECU does nothing but provide a conduit for the signals. If the AC turns off, its because the trinary high pressure switch was exceeded and cut the signal to the ECU. The ECU can control the AC fan separate to the AC and you will hear the AC fan kick in when engine is overheating independent of AC. I assume the ECU is responding to other input signals for that to happen. If your AC is turning off on hot days and we know its controlled by the trinary switch, possibly your AC fan has blown a fuse or something has gone amiss in that wiring network. Test it by turning on AC and if fan on the condenser does not turn on, bingo. One problem solved.

Or possibly two problems. If your AC was causing the fan belt to slip, could be a worn bearing in the AC or as above, the compr was competing with high pressures and for a better word, stalling under the higher pressure on the output side of the AC. The trinary is after the condenser and dryer so should have been cooled and pressure reduced to within range. If the symptom rectified turning the AC off, i'd put money on the high pressure as the cause which points to inadequate condensing. A bad bearing should be present whether the clutch is engaged or not.

As an aside, i had a sticky injector and would cause intermittent spikes in temp. I ignored it for too long and burned a hole in a piston. The first time it happened was on a long steep climb in the Blue Mountains. After that it would happen at any time.

Why the torque management kicks in, is beyond me. I suspect its related to the a temp input. The 2.2 only has coolant temp sensor. the 2.4 has a head temp and coolant temp. I'm struggling with the same problem with retardation of fuelling. But mine happens in any weather and any temp. Mine does it when i'm under full load and trying to accelerate. Ie an inclined on ramp to hwy or any hill. Once it falls into the retard state, only coming off the gas will release it. There are occasions i feel the torque management kick in, retard fuel, is released and kicks in almost immediately. You can feel the surging as it retards, releases and retards again. I suspect my intake &/or MAF may contribute to the problem but i've not done any experiments other than i can trip the vacuum gauge even with a new filter. I run a Nugget Air box and hosing from a Safari snorkel. Been living with the problem for years and none the wiser. FWIW, the Puma filter has a larger filter surface area than a 79 series & GU patrol. falls short of a 200 series filter. its limitation is in the pipe work not the filter itself. I've decided to go LS and be done with the Puma engine.

I'd be interested if the AC is the or contributing to the problem. Would love to be right and equally love to learn.