Outer Limits 4x4 Board

Hi guys,

I have a 93 disco who on the freeway tends to creep up to 3/4 on the temp gauge. Around local areas 60-80 it sits on half?

I have had the radiator unblocked and cleaned, and also thoroughly washed out the condenser unit in the front. Still not helping??

Any ideas? I was thinking thermostat next?

what engine????

3.5lt V8 on LPG

id check for bubbles in the header tank when its running (head gasket)

oh, that does not sound good. What kind of bubbles? Like just from the coolant getting hot?

Cause when it is running you can hear some noise coming from the header tank.

Does it make any difference than when you slow back down to 60 -80 it comes back to half?

with the radiator cap off and the engine running if the head gasket is blown compression gasses will leak into the cooling system causing bubbles
also remove the oil filler cap and see if there is a milky substance under the id (water mixed with oil)
that will tell you if it is leaking into the crankcase

Right,

thanks i will check that out, but i know that there is no milky oil under the lid. Cause I have checked that before.

The header tank does get quite warm.... but i will check for bubbles. Now, am i looking for just bubbling coolant? or am i looking for a bubbling milky coolant substance?

Thanks

just coolant but possibly could be milky ***be carefull opening hot tank***
gets even experienced mechanics some times

Hi, yeah I had a look and it seems to have a very little bit of foamy sitting at the top.

Drove it around for about 15 minutes and checked it again at it is now gone??

My mechanic reckons that it could just be from the fact that the radiator was cleaned out and the coolant could sometimes get like that.

Change your thermostat its probably stuffed.It shouldnt go past half way on your temp gauge.

I had this problem also, had the cooling system cleaned, but the problem didn't go away til the radiator was removed and rodded.
If it was not done this way then I would look at getting it done first up.
I went through all possabilities, even did the head gaskets
If you remove the radiator yourself a good rodding should only cost around $100.

Ok, I have had the radiator out and they reckon they did clean it out with some sort of rod??? is that the same as the rodding your talking about?

I also had the thermostat changed and still has not changed anything, any more options other than a head gasket ? Chemiweld?

What is the head gasket repair worth these days?

The other options are:
an air lock from when the coolant was added
stuffed viscous coupling in the fan

mine was getting warm when being worked hard towing or off roading and was in the same boat as disco 95 and spent a fortune on mine - head gaskets, rad, thermostat and everything else i could think of, still doing it
one day whilst working under the bonnet the sagging heat/sound sheild fixed on underside of bonnet was doing my head in so i ripped it off and have never had it over half way since - go figure
turns out the heat/sound shield thing was smothering the engine and when working wasn't allowing the air to flow around enough to cool it

Have you considered leaning of lpg on hwy leading to more heat production??? Rover v8's don't like being run lean. Perhaps a retune would fix it. Mechanic can do a CO (carbon monoxide) test to confirm gasket failure.

dck7aok wrote:Have you considered leaning of lpg on hwy leading to more heat production??? Rover v8's don't like being run lean. Perhaps a retune would fix it. Mechanic can do a CO (carbon monoxide) test to confirm gasket failure.

I had a sniffer on my expansion tank too, screamed its tits off, that's why I did my head gaskets. The engine still ran too hot.
It could be as easy as timing.

Viscous fan?

Snerk wrote:Viscous fan?

Yeah, that thing behind th eradiator that spins really quickly.
It runs on an oil that thickens when it gets warm.

Snerk wrote:Viscous fan?

Nope, it would run hot when travelling slow and cool down on the freeway if that was the case

Hi,

Is it really running hot or just what the gauge says? Bad earth to the gauge or sender (unlikely) will give reading hotter than it really is. Bad earths to instruments are pretty common in older cars.

DL

DL wrote:Hi,

Is it really running hot or just what the gauge says? Bad earth to the gauge or sender (unlikely) will give reading hotter than it really is. Bad earths to instruments are pretty common in older cars.

DL

More resistive connection will show as cooler temerature

Thanks for that, I thought it was the other way round.

Had an XW 302 years ago that always ran 'hot' (!/2 to 3/4 on the gauge). Tried different thermostats and even got a triple core rad made, all to no avail.

It was only when I tightened the loose earth wire to the instruments that the gauge read properly. Other weird probs were sorted by this also. Must have been something else going on......... a long time ago.

cheers, DL

Hi All,

Ok, I have had the thermostat changed, radiator cleaned out and given a good rodding!, viscous changed (Other one was cactus anyway), and still have the same issue.

Mechanic, who i trust assures me that it is not a head gasket. The needle still creeps a needle width up to 3/4 on the hwy.

Around town it shoots to half and on long steep hill climbs it gets over half! It is driving me nutz!

What next? tuning? LPG running to lean? Drive it till it blows up?

Hi,

There's a thread on aulto atm similar to this. Check your vacuum advance by sucking on the tube and seeing if the plate moves inside the distributor. Ignition could be retarded under load.

Gas guy I saw once said they run hot on gas when rich, rather than lean. (Matt may correct me.........)

cheers, DL

sickgm wrote:Hi All,

Ok, I have had the thermostat changed, radiator cleaned out and given a good rodding!, viscous changed (Other one was cactus anyway), and still have the same issue.

Mechanic, who i trust assures me that it is not a head gasket. The needle still creeps a needle width up to 3/4 on the hwy.

Around town it shoots to half and on long steep hill climbs it gets over half! It is driving me nutz!

What next? tuning? LPG running to lean? Drive it till it blows up?

How does it smell hwen it gets warm. Mine definately had a hot smell to it befor any symptoms showed.
If it doesn't smell hot then think about your sender.

Hey Guys,

My mechanic took my car for a spin and the temp gauge creeped up to 3/4.... he drove it a little longer up and down the freeway and we he got back to workshop and put his infared thermometer on it and the hottest part in the engine bay was 92 degrees.

So i assume it is my sender unit? 92 degrees sounds about normal right?