temperature question

I have a 300tdi from a 94 disco. As the car lived in the middle east the bonnet has been raised slightly on it's hinges creating a gap of around 1 inch between the wing and the bonnet to help cool the engine. The Air-con radiator is also under the car to help with cooling.

All this means that car sits at cold for a good long while when beginning a journey, before very slowly getting to 72-74 C. The weird thing is now with the winter, it's happy to drop down to 60 again if the car stops in traffic.

Should I be worried? It seems like it never gets hot enough.

I have checked the thermo and it's 88. Should I take the fan off? Muffle the grill? Or be happy that it's cool rather than hot?

Personally I'd be happy it was staying cool !

Don't colder engines return better fuel efficiency?

doriz said:

Don't colder engines return better fuel efficiency?

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If this is good fuel economy then I'd hate to see bad.

doriz said:

Don't colder engines return better fuel efficiency?

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No. You want cool dense air coming in with the fuel, but the engine needs to get hot enough to thin the oil (reducing friction) and combust the fuel fully. The thermostat is there to help the engine warm up as quickly as possible.

NiallRussell said:

I have a 300tdi from a 94 disco. As the car lived in the middle east the bonnet has been raised slightly on it's hinges creating a gap of around 1 inch between the wing and the bonnet to help cool the engine. The Air-con radiator is also under the car to help with cooling.

All this means that car sits at cold for a good long while when beginning a journey, before very slowly getting to 72-74 C. The weird thing is now with the winter, it's happy to drop down to 60 again if the car stops in traffic.

Should I be worried? It seems like it never gets hot enough.

I have checked the thermo and it's 88. Should I take the fan off? Muffle the grill? Or be happy that it's cool rather than hot?

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I'd drop the bonnet, sounds like it's over cooled. It should get up to operating temperature within a few miles.

hmmm... dropping the bonnet isn't that easy. I would have done it years ago if I could. The upright part of the hinges seem to have been lengthened and welded. I will take off the fan or block the grill

Sounds to me like it's just the thermostat has been removed or is siezed open, though my guess would be it's been removed, seeing as it was in the middle east.

NiallRussell said:

I have a 300tdi from a 94 disco. As the car lived in the middle east the bonnet has been raised slightly on it's hinges creating a gap of around 1 inch between the wing and the bonnet to help cool the engine. The Air-con radiator is also under the car to help with cooling.

All this means that car sits at cold for a good long while when beginning a journey, before very slowly getting to 72-74 C. The weird thing is now with the winter, it's happy to drop down to 60 again if the car stops in traffic.

Should I be worried? It seems like it never gets hot enough.

I have checked the thermo and it's 88. Should I take the fan off? Muffle the grill? Or be happy that it's cool rather than hot?

Click to expand...

I don't know what sort of a temperature gauge you have on yours. I have a standard one on my 200 tdi and the needle sits about one third of the way up and just sits there. Mine also takes ages to warm up. I have posted several threads on here to try and see if there was a way of improving warm up. There doesn't seem to be. I have tried removing the fan completely. Fitting a Kenlow electric fan, Rad muffs, Linoleum over the rad. several new thermostats including a 88 degree one, New Rad, New heater matrix, stripped and cleaned out the heater etc, and it never made the slightest difference. I also insulated and sound proofed under the bonnet. It just keeps chugging along. The heaters in mine are crap. I have fitted a 300 w ceramic electric heat which helps and bought myself a warm coat, hat and gloves. I have now given up trying to get more heat out of it and improving warm up time. To give you some idea, in the dead of winter mine will sit at cold on the temp gauge for about ten miles before the engine reaches temperature. Several folk on here have concurred 200/300 tdi's just run cold. One or two sadistic ba-ta--ds said there's was as warm as toast. I came to the conclusion they must just eat cold toast.

That makes me feel a little better. The ten miles to warm up sounds about right.

ProcrastinatorFraser said:

Sounds to me like it's just the thermostat has been removed or is siezed open, though my guess would be it's been removed, seeing as it was in the middle east.

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I had the thermo out and put it in a little pan of water, but I will check it again, as it was about a year ago.

NiallRussell said:

That makes me feel a little better. The ten miles to warm up sounds about right.



I had the thermo out and put it in a little pan of water, but I will check it again, as it was about a year ago.

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Yeah, that would be a good place to start, i don't really know what else it could be!

Also check what temp the thermostat opens at, I have tried 4 different stats now (2 genuine and 2 bearmach) all 88 and all were opening between 83-92c except for one that opened on 88c on the money.

NiallRussell said:

That makes me feel a little better. The ten miles to warm up sounds about right

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Sounds very similar to mine mate.

a big gain is to be had by sealing as many drafts as possible, adjusting the heater to the best it can be and insulating the landy as best as possible.
I have done all the above to mine and the difference is vast

My 300Tdi was the same up until about six weeks ago when I took the stat out to check. Stuck open. Put a new one in and the temp gauge now gets to about a third of the scale in about a mile and a half. It took 10 miles at 55-60 on dual carriageway to even start moving before that.
It still takes about five miles before any significant heat comes through the heater though. Having said that, it starts demisting the screen very quickly. Even when still on the drive.

Check your vehicle has not been fitted with an up rated rad given its history,compare yours with a known standard one.
During cold weather I cover the lower half of radiator with a piece of correx [ sale sign board ] tight against the rad.
So called rad muffs no good the air just goes around behind them.

Al2O3 said:

My 300Tdi was the same up until about six weeks ago when I took the stat out to check. Stuck open. Put a new one in and the temp gauge now gets to about a third of the scale in about a mile and a half. It took 10 miles at 55-60 on dual carriageway to even start moving before that.
It still takes about five miles before any significant heat comes through the heater though. Having said that, it starts demisting the screen very quickly. Even when still on the drive.

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Your lucky getting some significant heat coming through. On the plus side on mine it's so cold the windows don't mist up.

mikescuba said:

Your lucky getting some significant heat coming through.

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Yes, I know. It's now ok for demisting pretty quickly, takes about 8 miles for decent heat to come through. Even on very cold mornings.