Couple of theories on the diesel cool running problem?

[T-Cut]

I'd say you have an unusually cool running example of the M47R. You've done everything most people do to get warmer, but it's not helping much.

If it doesn't have one, fit a full undertray and blank off the front grill during the cold weather. Don't use the sircon system.

TC
Sorry symultanous posts.

[FrenchMike]

You ask the question "is the temperature sender faulty?"

I would say ,easy to check with the OBD

Start from cold and check the ambient temp ,then follow the increase.

It' simply a negative coefficient variable resistor

[clf]

Originally Posted by FrenchMike

You ask the question "is the temperature sender faulty?"

I would say ,easy to check with the OBD

Start from cold and check the ambient temp ,then follow the increase.

It' simply a negative coefficient variable resistor

It rises, the readings I have obtained are from the obd. I am wondering if it is under reading, as the temps are pretty consistent, but read approx 10 degrees less than I think they should be. ( DG normal running, cruising at any speed, once operating temp should have been reached, the obd reads 75.)

[clf]

Originally Posted by T-Cut

I'd say you have an unusually cool running example of the M47R. You've done everything most people do to get warmer, but it's not helping much.

If it doesn't have one, fit a full undertray and blank off the front grill during the cold weather. Don't use the sircon system.

TC
Sorry symultanous posts.

I do have the full under tray and don't use air con much. I tried blocking part of the grill 2 summers ago, it raised the temp by around 3 or 4 degrees

[T-Cut]

Interesting poblem.
If you don't use the internal heater, try clamping one of the hoses to stop/reduce flow through the bypass loop.

TC

[clf]

How big of a job would it be to replace the sender? I am guessing it is an air intake off job. If it is , I will replace it later in the year when I have more time .

I am guessing this question hasn't arisen before? Unless someone does it in the next couple of months, I will try it anyway. If nothing else it will eliminate it. I'll order a new sender tonight.

[clf]

Originally Posted by T-Cut

Interesting poblem.
If you don't use the internal heater, try clamping one of the hoses to stop/reduce flow through the bypass loop.

TC

Where would the bypass hose be? I can't visualise it in my head and by the time i get home it is too dark, cold or wet to work at it

[FrenchMike]

Originally Posted by clf

It rises, the readings I have obtained are from the obd. I am wondering if it is under reading, as the temps are pretty consistent, but read approx 10 degrees less than I think they should be. ( DG normal running, cruising at any speed, once operating temp should have been reached, the obd reads 75.)

an offset of 10 degrees less means some extra resistor.

my chart says:

0 deg=4584 ohms
10 " =4364 "
20"=4016"
50=2750"
60"=2267"
70"=1862"
80"=1490"

Mike

[Avulon]

Mine has also always been a few degrees lower than expected even with the renault 5 stat in place - so definitely one thing to check the connections at the temp sender then.

[T-Cut]

I'd say the chances are the sensor is OK. Engines that 'seem' to be running too cool usually are.

TC