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Hi,

Noticed the last couple of times I've been out and driven on motorways etc the my engine temp drops the faster I go....and it’s not that fast :D. As soon as I hit 60+ the temp gauge drops from half to 1/4 or if not below gradually. If I slow to 55 or drop behind a vehicle temp restores its self to 1/4.

Should I be concerned :confused:?

Merry Christmas
 

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Hi,

needs a new thermostat. you might find it doesn't even have one!
I fitted a new one when I got it, don't why I did, but did.

What would happen if I kept flooring it till the engine got temp got cold?

or is it getting cold?

I do need to refit the belly pan but not sure if this is the problem?

Merry Christmas
 

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Might be a faulty stat but they do get colder on faster driving this time of year because the water is moving faster around the engine and the radiator has colder air blowing through it.
 

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dont know if you still can, but they used to do winter and summer stats, dont know if it because iz old school but we did used to block half the rads off on some cars in winter cos they just didnt get warm, could also be cos its :eek: cold, belly pan might help and also stop n salt from eating your electrical conections,
dont know how to work out wind chill factor but i ant seen any dogs with there heads stuck out of windows for a while now*<:)>LOL:
 

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I know its cold, not sure the extra 5 mph I do makes a difference in wind temp.

Could it have to much coolant?

Sorry, I haven't mentionted that its a 2.5 petrol AAF auto 1993 K Reg.

Any way, I'm going to fit the belly pan on today, if I can find me gloves as we got some snow in Dorset last night and wana go and see how the velle handles H:

Merry Christmas.
 

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Does anyone like riddles? Been meaning to post this for a while. This problem sounds familiar. If you find a solution let me know.
My wife's '97 1.4 Polo does the same, but worse- now it's cold it won't even get up to temp.
It is potentially serious. Check you're oil filler cap. The Polo was showing that the oil was emulsifying badly, and obviously can't protect the engine as it should.

The car had this problem when I bought it last year. I thought it probably didn't have a thermostat. It did, but I fitted a new one in case the old one was sticking open. It didn't make any difference.

I blocked up about a third of the radiator with cardboard and that did the job, as we were coming into spring.

Now I've had to block the radiator up completely, and it's running just how it should. Perhaps the fan comes on a touch early if you've been sat in traffic, but (at least in this cold weather) it's not staying on longer than usual. When it the weather warms up I'll take some cardboard out.

I feel like offering a prize for anyone who can come up with the right cause of this problem. :confused:
There will be a booby prize to the first person to write 'old Land Rover' though LOL:

Cheers all, Happy Christmas,
Pete
 

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Mate, My 2.5 TDI does exactly the same thing. Would give anyone multiple beers if they can find the cause.
Thermostat Changed
Header Cap Changed
Temp sender changed x2

Bottom rad hose never gets warm even after driving for miles.

Heater varies in temperature with Temp gauge so I believe the temp gauge.

10 pounds beer tokens to the man (or woman) who can come up with an explanation.:ILU:

If anyone says thermostat they hav'nt read the post properly.T:
 

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Mine taskes a while to get up to temp, no sign of emmulsify, and on long journeys fast on motorways ist really keeps cool, I too have the belly pan removed. Manye the belly pan is the missing link?

If i sit in traffic, then it starts to climb up, and in the summer the fans will kick in. but in winter it rarely gets up to 1/4 way. But i don;t do a lot of sitting in traffic...
 

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10 pounds beer tokens to the man (or woman) who can come up with an explanation.:ILU:

If anyone says thermostat they hav'nt read the post properly.T:
I,d bet its the thermostat.

Seriously though we all know deep down the real cause, if you smoke its because youre a smoker. Ask a doctor everything is because youre a smoker. For everyone else its because of global warming.
Just for the record mine has been doing the same thing over the recent cold spell. Slow driving round the town heats up well but above 50 on motorways and temp starts to drop to about 1/4 on temp gauge. Im guessing this is where the thermostat closes again til the temp rises icy coolant in the radiator gets to block drops temp again closing the thermostat and just continues like that. But thats just a professional guessI:
 

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Cheers for the help.T:

Problem is, when I first got the van it came to temp quickely and ran fine.
Even through last years cold snap in Febuary it had been great: strait to 90 and sat there till the cows came home.

Then I drove it to Ireland and back in the summer and since then it has been running cold, unless I really give it some beans. I can drive 20 miles and it won't come off the stop, and the heater is luke warm. Get on the motorway at 75 and it climbs slowly to 90 and sits there, until a 50 limit and it drops back to a quarter.

All the time the temp of the heaters matches the temp of the van.

Someone suggested water pump not pumping effectively but it has never overheated.:confused:
 

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5 mph makes a small difference in air temperature but it could be enough to push your antifreeze to the limit, and the longer you're at this speed then things will slowly get worse if your antifreeze is on it's limit. Top up slightly to say the max, see if it makes any difference, it's the cheapest solution if it works. Of course don't use waterT:

Remember if it's -5 deg C outside like it has been in some of the warmer parts of the UK this/last week then the air hitting your radiator is -18 at 70mph.

If it's -16 outside and your hitting 70mph then it's -35 hitting your radiator.

This would also work the same for Summer but the other way around, it also acts as a coolant you see.

Could be that, could be an air lock in your radiator, can van rads be bled for air, not sure?
 

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Beer Still up for grabs for any takers?I:
your thermstat is stuck open and your auxilary water pump (electric bottom of rad) is possibly not functioning properly, or stuck on.

change the thermostate (get one from vw) check the aux pump runs, (apply power 12v, to the connector) if you hear it ticking, then measure its current load when the engine is started from cold (it should not run untill the engine is upto temp)

check the thermal switch which is located on the front top right of the engine (cooling pipes coming in and out of it) 5 quid!!! measure voltage at the pump connector when engine is warm (run stationary for 20 mins) to test pump comes on and off.

mine did the same, and replacing the thermosat and thermal switch, after testing the pump was ok, fixed it.

however prior to doing all this, i checked the vains open and close on the back of the rad, they maybe stuck open. or if it had a over heating problem in the past jamed open. these open and close with rad temp. letting more or less air through the rad.

its also common if the aux pump does not run, to take out the thermosat as it causes the engine to run hot. this will give exactly the same symptoms as stated, i.e running really cold. as will a knackered thermosat.

if you change the thermostat and it then runs hot, its likely the aux water pump is not running at all. :)

expect a bear :)
 

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Cheers for the post.

Some cracking advice.

Is the themal switch a 2 pin blue situated about the main temp sensor.

I have a sneaky suspition that could be the culprit. If it was faulty would that make the aux pump run overtime?

MarkT:
 
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