2003 Discovery, Getting too hot.

[getlost4x4]

Quick question: 2003 Disco (94K miles) keeps getting hotter than it should. Hasn't overheated yet. I've been able to get stopped and cooled down before if exploded.

It looks to have a new radiator (but as I flushed it last night, lots of crap came out), i just put a new thermostat in it, the coolant reservoir cap is new, the viscous fan is working.

I'm going to go get the exhaust gas testing kit now to test for a blown headgasket.

What else could I check? The only other possibilities seem to be a clogged radiator (internally) or bad water pump.

The engine sounds and runs great otherwise.

Any ideas?

 

[DiscoDavis]

did you burp the air out of the coolant loop?

 

[howirolla]

did you burp the air out of the coolant loop?

this

mine did that a couple times recently, I burped the system and it hasn't done it since.

 

[99Discovery]

Burp out the coolant loop as suggested. You will know you need to do this if you hear what sounds like a "waterfall" behind the dash. Scary as heck, mine did it the 3rd day I owned it....but quickly burping it will silence Old Faithful.

Which thermostat did you put in? It is imperative to put in the TD5 180 degree thermostat to get that motor back to decent and manageable temps. I'm assuming you are using an ultraguage or OBD2 reader to view them in real time, because as you know (but some reading may not), when the gage creeps up you are already above 220F which puts you in the dangerous zone for head gasket issues.

There is a 3rd party 180 degree T-stat which is cheaper but hit and miss. Testing on landroverforums.com shows that this T-stat can be excellent to actually a 190F T-stat. The quality control isn't as good.

I didn't risk it and bought the TD5 Land Rover part. It was only $50 and an easy swap. Hooked up the ultragage and went from 220F under a light load to 188F. I think my old one was stuck. Now I sometimes hit 194F under normal driving and only 200F on hot days when the engine is soaked with heat (from off-roading/highway) and I slow down and the mechanical fan can't keep up.

Good luck!

 

[ColoDisco]

Have you pressure tested for leaks?

 

[Victory_Overland]

Quick question: 2003 Disco (94K miles) keeps getting hotter than it should. Hasn't overheated yet. I've been able to get stopped and cooled down before if exploded.

It looks to have a new radiator (but as I flushed it last night, lots of crap came out), i just put a new thermostat in it, the coolant reservoir cap is new, the viscous fan is working.

I'm going to go get the exhaust gas testing kit now to test for a blown headgasket.

What else could I check? The only other possibilities seem to be a clogged radiator (internally) or bad water pump.

The engine sounds and runs great otherwise.

Any ideas?

When you say "Lots of crap came out" what exactly do you mean? Are you the original owner and if not, could be someone did a half ***** radiator repair with internal stop leak. Same could be for someone who put an engine oil additive and if you do have head gasket problems, that could be your problem too. Does the radiator look to have any puncture areas? The fan is running all the time or according to temperature and thermostat? I second the LR thermostats as I've been through 2 aftermarkets on my LR3 and when I went back to the LR one, all was fixed.

 

[getlost4x4]

Ok. Did the exhaust gas test. It passed.

Pulled the water pump because I noticed it was leaking out of the weep hole.

The flushed the radiator. I noticed some crap coming out. Like stop leak product. I also flushed the engine out.


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[getlost4x4]

The previous owner must have done some half a**ed repair on it. I've only had it about a week


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[KyleT]

Be ready to replace the radiator, heater core and all the hoses if a good flush doesn't get all the junk out. Stop leak clogs these things up dirty style.


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[getlost4x4]

Yes. I know. At least the heater core seems to work well.


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[Victory_Overland]

I know this is a pain in the booty, but if it was my problem to fix I would put an LR thermostat in. While I am doing the thermostat, I would perform another fluid change since you have already re-pressurized the system from your last maintenance job you may have loosened some more of the stuff up. When you drain it, if you can do it from the bottom of the radiator hose attachment you will get a look at what is coming out. That stuff ruins water pumps so if you have more in the next drain, at that point I would do the radiator, lines, etc...

If you are seeing this material coming out of the radiator, water pump and thermostat housing, then it is surely in the engine journeys and most likely in the heater core as well. Expose as much of the system as you can for the flush so you are not just pushing it around to other areas of contention.

Sorry to hear about your luck. By no means is my suggestion mandatory, just what I would do. British Atlantic has full cooling replacement kits that come with lines, fittings, housings, etc... all in one package and depending on the condition, it might just be worth doing the whole thing.

Remember, lack of cooling could very well lead to head problems, or many other problems worse than just heads. You clearly have indicators or more than just a potential thermostat sticking if there is foreign material in the cooling system.

 

[pugslyyy]

Welcome to Land Rover ownership. Disco2 with an overheating problem, eh? Well the good news is you have plenty of company.

One of those little laser temperature probes is gold right about now - you need to figure out what's cooling and is not. If the block is okay (no evidence of head gasket failure, right?), then it's a hose or the radiator. Take a deep breath, as long as the motor as oil and water (separately) it is hard to do terminal damage. Could be hoses, could be rad core, could be pump - all these things happen and they aren't that crazy to fix, just make sure you are fixing the actual problem not shooting in the dark.

 

[ColoDisco]

I asked if you pressure tested the system for leaks as you can have a one way internal leak in the engine. Given someone may have added block sealer to your cooling system it's a good place to start and the number one place I start as a Land Rover technician. A exhaust gas tester for the cooling system will only show if it's getting into the coolant, not if the coolant is only getting into the combustion chamber. I know it sounds weird but I have run into this more than once.

A overnight pressure test will let you know if you have a slow leak down.

 

[TyScot]

Welcome to Land Rover ownership. Disco2 with an overheating problem, eh? Well the good news is you have plenty of company.

This guys not new to Land Rover's, check his RRC build thread. And I believe this isn't his first D2

When you get everything back together and burp the system again, elevate the front end, it'l help get any air out.

 

[rlynch356]

overheating is pretty common on the 3.9->4.6 engines and usually means the either the radiator is done or the head gaskets are.. I'm sure you know that if you've had them before.

do you have coolant in the oil? if so you need to do the gaskets pronto.
they seem to be a wear item