407 hdi 2.7 coolant temperature range

[407]

Hi

Ive just replaced the cooling pipe on my 2.7 Hdi with a new one 1351KT that came with a 2 pin temperature sensor ( 1338.E5 or 3L8A-12A648-AA stamped on it (also a Ford part it seems). I've bleed the system, its got antifreeze / antiboil coolant and heater on hot seems to be okay.

However, when running the car the temp reading via my Car Scanner Pro an app on the ODB port is between 94 and 97 degrees C, which seems a bit high (its winter here in Australia) and higher than the old one (based on where the temp guage needle sits. The temp guage now is also just over the middle marker (90 C) but nowhere near the 100 C marker.

On my petrol ES9 v6 407 the temp reading (sme app) is a more reasonable 74 (highway) to 90 degrees C (stopped in traffic) and way left of the 90 C middle marker

Is there a specification for what the 2.7 Hdi temp range should be ?

es9 tempguage

Could the new sensor be reading higher than the old one ?

regards

[407]

Seems the general consensus on google is

Optimal engine temperature is around 190 F to 220 degrees Fahrenheit (or 87 to 105 C). Most cars don't provide numerical temperature readings but show a hot-cold scale with a needle that sits around the middle.

I guess mine is around in the middle so perfect

[PaulC5]

I have found that thermostats are about 90°C starting to open and you can check this by feeling the radiator top hose when it starts to get warm. At the same time see what the gauge and code reader show. The engine fan will typically start at 96°C on a low speed and if a 2 speed will increase its speed a few degrees higher. It looks as if your temperatures are about right at 94 to 97°C and considering your winter temperatures may be similar to UK summer ones, they are comparable to what I would expect from our cars. If your car does not get to 90°C and the radiator top hose is getting warm before then, it suggests the thermostat needs replacing since it may be open all the time or opening too early which can result in poor fuel economy.

I would look into replacing the thermostat on the petrol car since it looks to be the faulty one and not the diesel.

[407]

So, having seen the temp on the HDI 2.7 go up to 111 C on a 25 C degree on the highway and the fan running at high speed all the time, I figured I better investigate some more before the pipes burst and I was stranded somewhere.

I also had a bit of a drizzle of coolant on the engine mount coming from the main thermostat rubbr hose fitting.

At first I suspected it just might be the DPF trying to ignite a cycle, but it just keep running hot.

Then I look at the radiator being blocked but water came out okay when it was flushed. I had also measured the temps on the pipes to and from the radiator and they seemed to be okay (eg 75-80 in and 45-50 out) so the radiator was doing its cooling job okay

Anyways, I pulled the thermostat out and despite it being on stove in hot water for along time (at least 100 C) it would not open. A spare new one worked fine so its going in but for the next bit.

However, in pulling the thermostat out, I discovered the 90 degree Norma fitting was perishing, hence the coolant leak (and now disabled car yet again). It looked fine until I touched it, and then it crumbled.

It seems Peugot engineers build an expensive car theory (albeit 16 years old now) is why use one rubber bent pipe to fit on a flange when you can use 5 plastic fittings that perish over time instead. Not like the old VW bettles / fastback what weer all metal and made to last (or until they rusted out).

See pics

Any idea what Peugeot part number on this would be (seems like a industry standard part) - numbers suggest its a Norma-RSS NQPS3 NW28 but google can't find it

cheers

[407]

Seems the whole hose and fittings part number is 1343.HK

The female flange fitting seems to have been replaced with a new part NORMAQUICK PS3 Quick Connector 90° NW26 - 32,4 mm which is silimar but not the quite same (see bits in yellow) .

[Rp0thejester]

If your looking for part numbers you need to post in the parts thread so GiveMeaBreak can see it

[407]

So I changed the thermostat and decided I would try a fix for the Norma connector whilst waiting for the new one (a few weeks away as no stock in OZ) and otherwise the car was disabled.

I found a plastic pipe that fitted loosely inside and used JB Weld to seal it inside plus a bit more on the outside to replace the broken bits.

Car now runs okay - no leaks so far and temp is sitting between 90 and 95 C plus fan is not runing at high speed anymore so seems it was the thermostat after all.