Re: Greetings from Spain!
Posted: Sun Sep 17, 2017 4:14 pm
Hi Denis, and welcome!
Our's is a 2.5 too (Malaga region) and driving exactly the same sort of roads yours does.
What you describe with the temperature gauge sounds perfectly normal, and what you should expect from a 2.5...
Gentle driving: gauge shows a little under 90C
Push a bit: 100C
Push hard: 110C
Pushed extremely hard (steep hills and towing), gauge might show 110-115C, but coolant will not boil, as it is pressurised, and the fans will operate at high speed. At these very high temperatures, the engine electronics will reduce the air conditioning, and finally reduce fuelling, to prevent severe over-heating. Very clever stuff!
For normal driving, if you switch on the AC, the cooling fans will immediately operate at slow speed, and - despite some extra heat produced by the AC 'radiator' at the front - it will actually help keep the engine temperature down on steep hills: a bit of "extra manual cooling", if you like.
Coolant level:
Handbooks and some documents suggest that the coolant level should be maintained a couple of cm above the top of the vertical level marker inside the coolant header (expansion) tank. I have tried this, but find that coolant is ejected (via the overflow pipe next to the expansion cap) when the engine gets hot. When it cools, the level will settle about 2cm below the top of the level marker. On ours, it will stay at this level for months on end. Try it.
Bleeding:
On the 2.5, it is important (as John says) to bleed the cooling system properly whenever the coolant is drained or replaced.
Procedure is as follows:
- While engine still cold, fit a "header bottle" (1-litre will do) into the neck of the header tank... I found an old bit of large radiator hose makes a snug fit inside the header tank neck, and blocks off the drain hole in its side.
- fill the cooling system through the bottle, so that it becomes half full.
- open each of the four bleed screws in turn, to allow any trapped air to escape:
(a) top right corner of radiator (plastic thumb screw)
(b) hose leaving the water-cooled intercooler (tyre-type screw-on cap)
(c) small hose bend to the right of the header tank (knurled and slotted plastic screw - don't over-tighten)
(d) heater feed pipe (horizontal steel pipe between engine top cover and bulkhead/firewall - brass socket-head screw sticking upwards - loosen only until it dribbles, do not remove or lose!
- When initial air is gone (keep the header bottle half full), start the engine, and allow to run until it reaches working temperature, and the fans have cut in (slow speed) at least twice. This may take 30++ minutes, as the diesel uses tiny quantities of fuel.
- During the warm-up, air will bubble up into the header bottle. Keep it half full, and encourage the air to find its way out by frequently squeezing the large radiator top hose.
- Speed up the engine to 2000rpm now and again, to encourage additional bubbles out.
- Open up the four bleed screws in turn, to release and air still trapped.
- When no more air emerges (bleed screws and header bottle), allow the engine to cool completely with the header bottle still in place and half full. The level in the bottle will drop as it cools.
- When cold, gently ease up the header bottle and its tubing: unwanted coolant will drain away through the small neck drain tube.
- Remove some coolant from the header tank to bring it down to the correct level.
A bit of a job, but worth it to ensure there are no air pockets left in the system, especially the head.
Hope helpful.
For coolant, I'd recommend Peugeot-Citroen's own "Pro" Coolant, made and available in Spain over their parts counters. It's very high quality and not expensive. Use neat; do not dilute.
Our's is a 2.5 too (Malaga region) and driving exactly the same sort of roads yours does.
What you describe with the temperature gauge sounds perfectly normal, and what you should expect from a 2.5...
Gentle driving: gauge shows a little under 90C
Push a bit: 100C
Push hard: 110C
Pushed extremely hard (steep hills and towing), gauge might show 110-115C, but coolant will not boil, as it is pressurised, and the fans will operate at high speed. At these very high temperatures, the engine electronics will reduce the air conditioning, and finally reduce fuelling, to prevent severe over-heating. Very clever stuff!
For normal driving, if you switch on the AC, the cooling fans will immediately operate at slow speed, and - despite some extra heat produced by the AC 'radiator' at the front - it will actually help keep the engine temperature down on steep hills: a bit of "extra manual cooling", if you like.
Coolant level:
Handbooks and some documents suggest that the coolant level should be maintained a couple of cm above the top of the vertical level marker inside the coolant header (expansion) tank. I have tried this, but find that coolant is ejected (via the overflow pipe next to the expansion cap) when the engine gets hot. When it cools, the level will settle about 2cm below the top of the level marker. On ours, it will stay at this level for months on end. Try it.
Bleeding:
On the 2.5, it is important (as John says) to bleed the cooling system properly whenever the coolant is drained or replaced.
Procedure is as follows:
- While engine still cold, fit a "header bottle" (1-litre will do) into the neck of the header tank... I found an old bit of large radiator hose makes a snug fit inside the header tank neck, and blocks off the drain hole in its side.
- fill the cooling system through the bottle, so that it becomes half full.
- open each of the four bleed screws in turn, to allow any trapped air to escape:
(a) top right corner of radiator (plastic thumb screw)
(b) hose leaving the water-cooled intercooler (tyre-type screw-on cap)
(c) small hose bend to the right of the header tank (knurled and slotted plastic screw - don't over-tighten)
(d) heater feed pipe (horizontal steel pipe between engine top cover and bulkhead/firewall - brass socket-head screw sticking upwards - loosen only until it dribbles, do not remove or lose!
- When initial air is gone (keep the header bottle half full), start the engine, and allow to run until it reaches working temperature, and the fans have cut in (slow speed) at least twice. This may take 30++ minutes, as the diesel uses tiny quantities of fuel.
- During the warm-up, air will bubble up into the header bottle. Keep it half full, and encourage the air to find its way out by frequently squeezing the large radiator top hose.
- Speed up the engine to 2000rpm now and again, to encourage additional bubbles out.
- Open up the four bleed screws in turn, to release and air still trapped.
- When no more air emerges (bleed screws and header bottle), allow the engine to cool completely with the header bottle still in place and half full. The level in the bottle will drop as it cools.
- When cold, gently ease up the header bottle and its tubing: unwanted coolant will drain away through the small neck drain tube.
- Remove some coolant from the header tank to bring it down to the correct level.
A bit of a job, but worth it to ensure there are no air pockets left in the system, especially the head.
Hope helpful.
For coolant, I'd recommend Peugeot-Citroen's own "Pro" Coolant, made and available in Spain over their parts counters. It's very high quality and not expensive. Use neat; do not dilute.
