Bluest wrote:

I'm currently sat by a pool in Spain, beer in hamd, having driven down from the UK. Just.pindering this issue that has plagued Pumas since time immemorial. There is nothing new here...

Coming down over the Midi Pyrennees there are some very long Autoroute inclines. It was 34C ish ambient. If I sat at 100 km/h in top gear up some those very long climbs, the power would die. It would recovery eventually if I shifted down, lost speed and eased the throttle. But not before nearly being rear ended by a truck I'd just passed on one occasion! I've had worse problems when we were in the Pyrenees in 40c plus a few years ago.

Given the number of such motorway inclines in that neck of the woods, it was possible to try some mitigation strategies. It seems shifting down to 5th and dropping to 90 km/h is good for most situations, but it did recur once on a long steep grade. 4th 80-85 seems to solve the problem at those temps at least, but that's not pleasant in a Puma, which don't seem to enjoy revving.

On reflection it seems to me that relying on our Puma's ample torque puts too much heat into the coolant than the ECU thinks is safe. Has anyone properly solved this issue? There are fan spacers, alternative thermostats, bigger intercoolers and radiators.

It would be nice to have a solution that would allow at least 5th to be maintained at 100km/h if stating in 6th is too much to ask.

custom90 wrote:

That does sound like a faulty VCV to be honest as that is what happens with that, at least mine did but never puts up a DTC as that isn’t part of the system.

Beyond that, an Intercooler upgrade especially if any tune is present.
Fresh coolant also can knock a few Degrees off coolant and engine temps.

You really shouldn’t be losing power in 6th unless heavily laden or towing heavy, regardless of ambient temp.
Turbo actuator light lube, keeping clean MAF and MAP sensors and clean filters, fuel, oil etc all are good but a failing or aged VCV knock’s off top end power for sure.

I also just run regular diesel, but wherever possible I always run Millers Diesel additive and have now for about 60k miles. This is just what I do, but I think it keeps the turbo cleaner internally and the injectors.

Does anything here seem to ring any bells that might be any use?

I’ve tried an aftermarket supposedly “OEM” air filter before too, and when swapped back to Genuine could find how restrictive that was.
That’s why I stick to Genuine service parts, not cheap but you can get problems from other parts which is defeating the point of servicing anyway.

Zed wrote:

Bluest wrote:

I'm currently sat by a pool in Spain, beer in hamd, having driven down from the UK. Just.pindering this issue that has plagued Pumas since time immemorial. There is nothing new here...

Coming down over the Midi Pyrennees there are some very long Autoroute inclines. It was 34C ish ambient. If I sat at 100 km/h in top gear up some those very long climbs, the power would die. It would recovery eventually if I shifted down, lost speed and eased the throttle. But not before nearly being rear ended by a truck I'd just passed on one occasion! I've had worse problems when we were in the Pyrenees in 40c plus a few years ago.

Given the number of such motorway inclines in that neck of the woods, it was possible to try some mitigation strategies. It seems shifting down to 5th and dropping to 90 km/h is good for most situations, but it did recur once on a long steep grade. 4th 80-85 seems to solve the problem at those temps at least, but that's not pleasant in a Puma, which don't seem to enjoy revving.

On reflection it seems to me that relying on our Puma's ample torque puts too much heat into the coolant than the ECU thinks is safe. Has anyone properly solved this issue? There are fan spacers, alternative thermostats, bigger intercoolers and radiators.

It would be nice to have a solution that would allow at least 5th to be maintained at 100km/h if stating in 6th is too much to ask.

Are you sure it’s overheating due to ambient temperature? I wonder if you are cruising in a too a high gear and labouring the engine. At what revs do you cruise and when do you change up?
Also do you have an OBD gauge to accurately live monitor temps, revs etc?

Bluest wrote:

Zed wrote:

Bluest wrote:

I'm currently sat by a pool in Spain, beer in hamd, having driven down from the UK. Just.pindering this issue that has plagued Pumas since time immemorial. There is nothing new here...

Coming down over the Midi Pyrennees there are some very long Autoroute inclines. It was 34C ish ambient. If I sat at 100 km/h in top gear up some those very long climbs, the power would die. It would recovery eventually if I shifted down, lost speed and eased the throttle. But not before nearly being rear ended by a truck I'd just passed on one occasion! I've had worse problems when we were in the Pyrenees in 40c plus a few years ago.

Given the number of such motorway inclines in that neck of the woods, it was possible to try some mitigation strategies. It seems shifting down to 5th and dropping to 90 km/h is good for most situations, but it did recur once on a long steep grade. 4th 80-85 seems to solve the problem at those temps at least, but that's not pleasant in a Puma, which don't seem to enjoy revving.

On reflection it seems to me that relying on our Puma's ample torque puts too much heat into the coolant than the ECU thinks is safe. Has anyone properly solved this issue? There are fan spacers, alternative thermostats, bigger intercoolers and radiators.

It would be nice to have a solution that would allow at least 5th to be maintained at 100km/h if stating in 6th is too much to ask.

Are you sure it’s overheating due to ambient temperature? I wonder if you are cruising in a too a high gear and labouring the engine. At what revs do you cruise and when do you change up?
Also do you have an OBD gauge to accurately live monitor temps, revs etc?

No live data, although I think my Nanocom can do it.

The issue occurs when cruising at 60-65 in sixth, long inclines, high ambient temps. No towing, but quite heavily loaded. It has never occured in the UK for me.

Jerry wrote:

Can I ask - why is it bad to go into 6th under 70mph? I change up at about 56 - should I change my ways? Thanks (Maybe I have misunderstood).