300td temp gauge reading hotter

ONE LIFE LIVE IT. D90 said:

Thanks James. Even with the long trip ive got on sunday? I spose the stat will only remain open wont it

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yes a good system runs best and should run as long as you need at 88-90 ish

jamesmartin said:

yes a good system runs best and should run as long as you need at 88-90 ish

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Okay mate thankyou. Well ive ordered a new sender should be coming friday. If that fails, i spose its a new rad.
Should i cancel my journey then on sunday with it how it is?

no , take some water with you if you fel there could be coolant loss but your test the other night indicated engine wasnt too hot

jamesmartin said:

no , take some water with you if you fel there could be coolant loss but your test the other night indicated engine wasnt too hot

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Thanks very much James for all your help. Much appreciated. Thats relieved me.

ONE LIFE LIVE IT. D90 said:

Thanks very much James for all your help. Much appreciated. Thats relieved me.

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let us know how you get on take a few readings with your infra red gun as you go

jamesmartin said:

let us know how you get on take a few readings with your infra red gun as you go

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Had to make a 30 mile round trip tonight, country roads and some of which higher speeds. I thought i would use the land rover.

For about 15 miles, the gauge didnt budge on the slower lane driving, averaging 30-40mph. The temp gauge didnt budge, half way constantly. Once i reached high speed roads, the temp gauge increased to 3/4 and stuck there permanantly, it didnt budge over it. Anyway, got out after i waited for it to the temp to increase and it didnt. Probed it and all seemed fine. On return home, averaged 50 mph for 10 miles, again with gauge reading 3/4, got home and temp gunned under the bonnet. Results as follows:
Header tank 66
Stat housing 73
3 positions between glow plugs 75-80
3 core plugs under turbo 85-90
Both heater pipes 60ish including rail across rocker cover
Back of water pump 78
Both top and bottom hose 65ish

This sounds good to me what do you guys think? Faulty temp gauge then?

seems ok to me

as above, temps seem fine.

is this an orig 300tdi defender btw? so you have the proper sender and matched gauge?

also with ign on and you turn on dash lights, fan blower, the gauge doesn't rise does it?

trax said:

as above, temps seem fine.

is this an orig 300tdi defender btw? so you have the proper sender and matched gauge?

also with ign on and you turn on dash lights, fan blower, the gauge doesn't rise does it?

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I beleive its the original engine trax yeah. Im sure i checked the engine number some time ago and confirmed it.

And i havent tested that mate, so turn on driving lights is that? I have tried whether the gauge rose with lights on or off. And it didnt alter, i havent tried it with the blower though

ONE LIFE LIVE IT. D90 said:

I beleive its the original engine trax yeah. Im sure i checked the engine number some time ago and confirmed it.

And i havent tested that mate, so turn on driving lights is that? I have tried whether the gauge rose with lights on or off. And it didnt alter, i havent tried it with the blower though

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when i had an earth fault the dash lights and deffo blower on full made it rise as the current was going via the gauges. probably not that and just a bad sender.. but can't harm to check

Hi all

Sorry to dig this old thread back up again. But I'm still struggling to find the problem.

I've tried 2 new OEM senders and tried earthing the original LR gauge to the original earthing point on the bulkhead, as well as the gauges own earth.

Absolutely no luck at all the gauge rose to just before the red and stuck there solid again.

So I ripped the old gauge out very frustrated. And ordered a new vdo vision range gauge, a long with a sender to match.....

Anyway, I fitted them today, used the existing wiring and just changed the terminals for the back of the gauge where I needed to.

I took the land rover out for a run for 20 mins and once the vehicle had been doing 60mph for 10 mins the gauge hit 105 degrees Celsius.
I thought right, at least I finally know it's time for a new radiator. Got home and My mind was ticking away for a few hours and I decided to take the land rover out again, to see if it would keep getting hotter and hotter.
This time i was out for about 30-40 mins on fast country roads with an average speed of about 50mph. Just before I hit the dual carriageway the gauge shifted right up to 120, the max for my vdo gauge.

I pulled over, switched off the engine but left the side lights and ignition on. I then noticed that the gauge dropped once the headlights were turned off, it dropped from 120 to about 105 (still power to the gauge). I then flicked my hazard lights on, and with every click/flash of the hazard lights, the gauge would jump up a chunk, right until it was at its max reading for the gauge. Turn the hazards off and it would return to 105.
I then thought, how does it read when the lights are off.... And it seemed to be reading fairly normal.

What I find really annoying is that this didn't happen with the original land rover gauge because I was told to check with lights on and off.

I've cleaned up the main battery earth, but will do it again I think.

Can anyone help me here please of what to look for next? It's driving me insane and I feel a garage isn't going to solve It any better than I am without some serious time and money going into it.

Sorry for the long winded post guys, I'm just sick of it.

Many thanks

Here's a video I took that may help people understand what I mean

http://m.youtube.com/watch?v=UzPT8RUXVc0

sounds like a bad earth.

if you have checked the bulkhead earth, then go stick a wire from the gauge directly to the neg battery pole and see if that cures it.

if so, then put that wire to the bulkhead dash earth and see if that still works or use a multi and check resistance, and continuity.

could be a bad connection to the battery or corroded/ad internals of the dash earth wire.

trax said:

sounds like a bad earth.

if you have checked the bulkhead earth, then go stick a wire from the gauge directly to the neg battery pole and see if that cures it.

if so, then put that wire to the bulkhead dash earth and see if that still works or use a multi and check resistance, and continuity.

could be a bad connection to the battery or corroded/ad internals of the dash earth wire.

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Thanks trax, I'll try that mate.

I'm still not convinced my 300tdi has an engine earth, no body seems to know where to find them from the engine. Reason I mention that is because i beleive the sender earth's through the engine

engine should be earthed amply through the main earth cable on the transmission, temp sender does earth through the engine and a poor earth should give a lower temp reading, alternators can fail so as voltage produced is higher than should be ,which gives higher gauge readings and brighter lights

jamesmartin said:

engine should be earthed amply through the main earth cable on the transmission, temp sender does earth through the engine and a poor earth should give a lower temp reading, alternators can fail so as voltage produced is higher than should be ,which gives higher gauge readings and brighter lights

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Thank you James. I'll also drop my multimeter on the battery and see what's happening when the engine is running.
Should I be looking for around 13 volts on tick over?

It seems like an earth fault to me, because each click of the hazards, was very similar to disconnecting the sender wire and putting it straight to the engine block and the gauge moves furthest it can to the hot. It seemed very similar

ONE LIFE LIVE IT. D90 said:

Thank you James. I'll also drop my multimeter on the battery and see what's happening when the engine is running.
Should I be looking for around 13 volts on tick over?

It seems like an earth fault to me, because each click of the hazards, was very similar to disconnecting the sender wire and putting it straight to the engine block and the gauge moves furthest it can to the hot. It seemed very similar

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oh, it sounds a bit of a mess.

firstly, get a jump lead and stick it from your bat neg to the engine block. does everything now work?

i think you need to give your wiring a quick check over.

first, follow the neg batt wire. it should go to chassis rail and then gearbox/transfer.

you should also have one from the engine, iirc nearside to the chassis rail. all bolt points should be clean and crud free. grease/paint whatever em after you've cleaned them up.

if you are missing any then go buy 3 straps and do above.

oh and for the alt and bat, you are looking for around 12.4v ish standing, 14.4v ish running. your alt light on the dash should also work.

trax said:

oh, it sounds a bit of a mess.

firstly, get a jump lead and stick it from your bat neg to the engine block. does everything now work?

i think you need to give your wiring a quick check over.

first, follow the neg batt wire. it should go to chassis rail and then gearbox/transfer.

you should also have one from the engine, iirc nearside to the chassis rail. all bolt points should be clean and crud free. grease/paint whatever em after you've cleaned them up.

if you are missing any then go buy 3 straps and do above.

oh and for the alt and bat, you are looking for around 12.4v ish standing, 14.4v ish running. your alt light on the dash should also work.

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Cheers Trax. I've had a look at the main battery negative that runs to the gearbox, I've cleaned up the post on the gearbox however I looked at the (p clamp) part that earth's the cable to the chassis and what a state that's in. Hardly seems to be holding the cable, and the cable looks quite corroded.

I'm going to exactly what you say and take it from there

ONE LIFE LIVE IT. D90 said:

Cheers Trax. I've had a look at the main battery negative that runs to the gearbox, I've cleaned up the post on the gearbox however I looked at the (p clamp) part that earth's the cable to the chassis and what a state that's in. Hardly seems to be holding the cable, and the cable looks quite corroded.

I'm going to exactly what you say and take it from there

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yeah i really don't like that p clamp.

i run a cable from the bat neg to a chassis bolt, and another from the same bolt to the gearbox.

then another strap at the front from then engine to chassis.

cover it all in silicon grease or thin layer of paint to help prevent corrosion.

trax said:

yeah i really don't like that p clamp.

i run a cable from the bat neg to a chassis bolt, and another from the same bolt to the gearbox.

then another strap at the front from then engine to chassis.

cover it all in silicon grease or thin layer of paint to help prevent corrosion.

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I'll do exactly the same. Where is your engine earth ran from and to mate? Because I'm pretty sure I haven't got a engine earth, and I'd like to fit one. I don't spose you have an pictures do you?