DII overheating problems

[Jock The Rock]

Hey people, I'm Jock's brother and I bought a Disco II Td5 about 4 months ago. The last couple of months it has started overheating and during that time I have had work done on it to try and fix the problem.

Most recently I had the radiator cleaned out (yesterday in fact) only a small amount of stuff was removed, before that the thermostat was repaced and the coolant header tank and cap, all the radiator hoses have been replaced. The water pump is fine as well. I had a pressure test done on it and that came back fine as well.

Maybe i should put that down in order of work done, first it overheated and i got it checked out. I knew there were a few small coolant leaks and so had hoses replaced as were going soft and the header tank replaced because of a small crack.

Still got hot when I got it back, noted change in type of coolant but system had been flushed so I thought should be alright. Got concerned it was a cracked head or head gasket so had the pressure test done which came back fine.

Mechanic suggested process of elimination of header tank cap not sealing, problem with thermostat, or blocked radiator. Have gone through that list in that order with the water pump being checked last of all. Vehicle still overheated after replacing the cap and thermostat. I wont have a chance to drive it for the next 4 days but when the mechanic said the radiator wasn't blocked in a way that could cause the problem I decided getting any info on it would be a very good idea. The mechanic is going to take it while I'm away and see if i'm missing any symptoms (out of work hours so i won't have to pay for it)

Been running water in it because it was pushing stupid amounts of coolant out. The engine monitoring system hooked up to the motor says that the normal running temperature is somewhere between 87 and 95 degrees C

The vehicle tends to overheat when the engine is running at 2500rpm (about 100km/h in 5th) this happens on flat ground. When sitting on 2100rpm (about 90km/h) is fine on the flat but will get hot going up hills. Doesn't like 2500rpm in 4th either (80km/h). Haven't driven it for long enough in any lower gears up hills or on the flat to be able to work out if there is a trend. Speed limit is 50 around town and sits on 2100 in 3rd which it only complains about (gets hot) on long steepish hills. Once the vehicle has returned to a normal temperature and I resume driving those conditions still apply so will be normal temp on flat ground at 2100rpm.

When checking vehicle over while it's cooling down the only thing noticable is where the coolant has been pushed out of the headertank overflow. Nothing from the exhaust or hoses.

So far the only other theories I have heard are the fan belt is slipping, but cant hear it doing that if it is

The vehicle has done 260,000km and ran fine for the first 2 months. It has also been chipped with as far as I can tell a medium performance chip.

Jock is the one who likes messing with motors, I know roughly how they work but am quite happy for someone else who enjoys it more to do the work :)

Any ideas about what could be wrong with it would be much appreciated. Maybe it's just female but I already thought of that :) anyway i'll be away for 3 days so wont be able look at what you come up with until saturday night.

Think that should be enough info, hopefully not to much or that that it's to badly explained :D

Cheers Nick

[Slunnie]

When you cleaned the radiator,did you clean the outside of the radiator? The pack with mud and block up. Likewise with all of the other radiators that are in the cluster, especially the transmission cooler.

[bruiser69]

Hi Nick,

One thing you might check is that all air has been purged from system. There is a plastic purge screw in top hose that you release to remove trapped air.
Be careful though as plastic screw can get brittle & shear off. If it does replace with brass screw & temp resistant Oring to seal.
The other thing that can result in overheating besides slipping drive belt, is viscous fan. These have a bad habit of not locking up when old.
To test it heat hub centre with hair dryer until you can't touch it. You should not be able to rotate blades with your hand if OK.

Good luck..B

[justinc]

I'm tipping a Head gasket leak Nick, A pressure test etc won't show it up but the only way you can get such a displacement of coolant out of the bottle under load is a combustion gas leak past the gasket fire ring...It is a 1999/ 2000 model isn't it? If so, I would suspect that the head has shifted and the plastic dowels have deformed, causing the gasket to leak pressurised gasses into the cooling system.

JC

[Panya]

Nick it may be a waste of time but the only time I had a similar problem (albeit only once) was driving the D1 up a long hot hill; at the top stopped to help some friends who had broken down and expansion tank promptly erupted. Nothing wrong with cooling system but the intercooler hose to manifold had not been refitted properly - engine was working much harder than it should have and the result was a much hotter engine; hence the overflow. I hadn't noticed much difference in performance and it was just not fully tightened after a service...:twisted: So perhaps have a look round and check that all well will other bits and pieces in the engine bay??

[feral]

I'm tipping a Head gasket leak Nick, A pressure test etc won't show it up but the only way you can get such a displacement of coolant out of the bottle under load is a combustion gas leak past the gasket fire ring...It is a 1999/ 2000 model isn't it? If so, I would suspect that the head has shifted and the plastic dowels have deformed, causing the gasket to leak pressurised gasses into the cooling system.

JC


Sorry Nick but I will go with JC on this one. I have 'been there' and no amount of looking, cleaning, rodding and checking will eliminate the problem.

You need to make the decision now as any further delay could be causing further damage to the head and you do not want to replace that as well.

[Jock The Rock]

Thanks for the replies

I think Nick is having the head taken off sometime next week

Ill keep you posted

[Bundalene]

Hi, I had exactly the same thing happen to our D2 6 months ago car getting hot, fluid pouring out of the fill bottle. The problem was a failed viscous coupling on the thermo fan. I had a spare at home - swapped it and all has been good since.

Next time the engine gets hot, try turning the fan - if it turns freely, the viscous coupling is faulty. The fan should be locked up to the pulley when hot.

Erich.

[DiscoJakes]

I would agree with the fan story.

After similar problems I sat down one day with the rave cd and happened to notice that the thermostat, that was replaced, had the y pipes swopped around. Believe me it can be done.
Have a careful look.... something simple, BUT it did solve my problem of heating when I started pushing the engine a bit harder or towing. It didn't overheat otherwise. Now all is fine again

[Blknight.aus]

check the VC but I reckon by now even if it was that your head gasket is now on the way.

[Zute]

I'm gonna vote for the head gasket. But a good way to check the thermostat is to feel each end of the radiator end tanks. if water is not flowing, the end near the battery will be cold.

[Jock The Rock]

Yep the plastic dowels busted and as a result i'm lookin for a new head as well. Big ouch from the wallet :( Can any one explain why the pressure test doesn't pick it up.
Cheers Nick

[Mundy]

Hi, I had exactly the same thing happen to our D2 6 months ago car getting hot, fluid pouring out of the fill bottle. The problem was a failed viscous coupling on the thermo fan. I had a spare at home - swapped it and all has been good since.

Next time the engine gets hot, try turning the fan - if it turns freely, the viscous coupling is faulty. The fan should be locked up to the pulley when hot.

Erich.

How hot does the fan need to be before the fan coupling starts to grip?

About a week ago I noticed that the coolant level was way down on by 2004 TD5 Disco. Topped up and checked every day since but all seems well and temp gauge seems normal. However, on reading this thread, I checked the fan after a short run which seemed to heat every thing up (coupling very hot to touch). It seemed to slip very easily. When engine runs fan seems to turn and there is air movement but perhaps not enough?

Anyone know how much a new coupling is?

Mundy

[mateusz]

mundy,

i had overheating problems in my disco one. even when the engine was hot the fan seemed to spin easily it didnt lock to pulley. I thought it should have. anyways bought a new one for about 250 dollars and you guesses it: when motor hot, fan does not lock to pulley??? its difficult to find a test procedure of the viscous fan scouring the internet. If you have problems and suspect it tie it, fix it too pulley. be carefull though. for me it was 250 dollars wasted, however i have a new component making the land rover more reliable in bush!

cheers

matt

[Mundy]

mundy,

i had overheating problems in my disco one. even when the engine was hot the fan seemed to spin easily it didnt lock to pulley. I thought it should have. anyways bought a new one for about 250 dollars and you guesses it: when motor hot, fan does not lock to pulley??? its difficult to find a test procedure of the viscous fan scouring the internet. If you have problems and suspect it tie it, fix it too pulley. be carefull though. for me it was 250 dollars wasted, however i have a new component making the land rover more reliable in bush!

cheers

matt

Thanks, Matt, you've confirmed my suspicions. I checked the fan when engine was hot and there seemed to be a good draft being created but the fan still seemed to slip easily when I turned off the engine. Cost of fan/coupling now $361 so don't want to buy one and find exactly same as existing unit. I've only done 74k kms so I thought it a bit premature for the viscous coupling to have failed.

Cheers
Mundy

[pohm66]

Had an issue (actually twice in 5 Ks) over the weekend with Grimmy overheating going up a long tight windy hill (8Ks).

The temp guage very quickly shot up from normal to the red and lost power. As only doing about 30-40 Kph stoped quickly and coolant pouring our from the over flow tube. Once cooled down replaced the fluids, did this twice.

Once at the top we got to our destination with flat ground. no water in the oil, no discolouration or floaties in the coolant and no need to top up any more.

A couple of odd things did happen though.... 1) had the car parked the the shade and cool for about 1.5 hrs and when started the motor the temp guage was straight up to normmal operating temp. 2) on another short trip the temp guage suddenly dropped from normal temp to about a 1/3 and then climbed again.

Cruised on home, one eye on the temp guage, and happily sat on 100kph for over an hour.

From this thread thinking of checking the viscous coupling first... any other thoughts????

Cheers....

[mike 90 RR]

Had an issue (actually twice in 5 Ks) over the weekend with Grimmy overheating going up a long tight windy hill (8Ks).

The temp guage very quickly shot up from normal to the red and lost power. As only doing about 30-40 Kph ..... coolant pouring our from the over flow tube.


... Check the viscos .... Rod the radiator .... are the first things to do

[pohm66]

Whats "Rod the radiator"? mike

[mike 90 RR]

Whats "Rod the radiator"? mike

Rod the radiator means .....

Remove radiator from engine bay
Take it to your local radiator repair center
They take the top / side tank off to expose the internal cores of the radiator
Metal flakes from your engine block, gets jammed in these cores and blocks the passage which = overheating on laboured motors, or highway use + ect

They get a rod (about the size of your motor oil dipstick) and shove it down the cores to push the flake blockages out

They put the tank back on ... Refit to engine bay .... ask them "how blocked was it?" .... as this will give you a indication of how much did it contribute to overheating problems ;)



How old is your radiator & how often do you service it? ...

Mike

:)

[pohm66]

Thanks for the explaination Mike:)

Would say its the original so 10 year old now and last coolant change about 30,000 ago.

Don't know when last flushed though......<_<????

Paul

[mike 90 RR]

.....and last coolant change about 30,000 ago.


All I can say is :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek:


Hope the above is "explanation enough"


Your coolant is NOT protecting the motor and has most probably turned ACIDIC :( .... Change & flush it now :mad: ... Your suppose to do it every year (depends on brand)


Mike

:(

[Psimpson7]

coolant change isn't supposedly required that frequently with the new OAT long lifes that should be in the TD5.

30000KM should be fine. (i am reading it as the rad is original, but the coolant has been in for 30k km)

I also dont think you can get the TD5 rads rodded due to the construcion of them.

Rgds
Peter.

[mike 90 RR]

coolant change isn't supposedly required that frequently with the new OAT long lifes that should be in the TD5.

I stand corrected ... If he has the OAT's ;)

[pohm66]

Yep.... gotta have the OATS......

Was looking to do a flush soon anyways....the over heating has just brought it forward in the schedule.

Thanks for the input guys :BigThumb: