engine getting very hot. coolant eruption!

Hi
I have recently bought my first landrover. A defender 90 300tdi (1996). I was taking it on its first motorway journey the other day of 110miles. I had decided not to go above 60mph.

After 15mins of driving on the motorway the temperature gauge began to rise from the middle and quickly reached the red area. I pulled over and called the dealership.

He told me to fill the coolant with water, which i did. There is an electric fan at the front which i had running. i re-filled the coolant and started driving again. all was well for about 1/2 hour and the then the temp gauge was in red again. I pulled over let it cool down and then drove again. It wasn't long until it was in red again. when i next stopped the coolant was empty. it took about 6pints to fill. Is there a leak???

when i was filling it there was no water pouring on the floor but the areas below the coolant tank, all of the right hand wheel arch and suspension was clearly wet.

On local driving there is no problem and the tank doesn't appear to leak when parked.

Today i drove it back the same way and after 1/2 hour had to stop. i undid the coolant lid and it virtually erupted, flowing blue liquid everywhere; strange considering i'm only fillign with water?

I understand that land rovers are not really designed for motorways but surely this is not right!!

Please someone help.

Kind regards

take it back to the dealers and get them to fix it.

My 300tdi's spend most of their life on motorways and have no issues.

I agree with Barmatt but sometimes it isn't always possible to take it to the dealers so here are a few things to check for.

The eruption from the header tank doesn't sound good it's making me suspect some nastys but lets start with the basics first. Make sure the system is filled with water and there is no air in the system, you can undo the black cap at the top front of the engine to bleed it.

Now run the engine and drive it for 10-15 minutes to heat it up and get the needle to its about half way mark, go home and leave it idling, check the TOP radiator pipe, does it get hot? Eventually hot enough you cannot hold onto it?

If not then I suspect your thermostat has jammed shut, where the TOP radiator hose starts from at the engine, there is a sort of U pipe bolted to the thermostat housing with 2 10mm IIR bolts. Undo these, pull the U section off and remove the thermostat, take the rubber oring off it and refit just the oring and do it all back up. Take the thermostat and submerge it in a pan of water, boil the water, before the water boils the stat should have opened right up, if not it's fecked. Now go and drive without the stat in it on the motorway and see if it overheats now.

If it suits you better to do this than take it to the dealers you can try this and report back. A new stat will cost you £5.

thanks very much. fortunately the dealer is very good and i have spoken to him today but just wanted some other opinions too.

He reckons the seal around the coolant tank is broken and hence not cooling the water properly. and hence the leaking on the wheel arch.

he has ordered a new part for me which he says i will be able to fit but failing that to take it back to him and he will get it sorted.

will keep posted.

The seal around the coolant tank? Not convinced about this.

You should be able to run it with the header tank cap OFF, as the water should never boil, so why having this "seal" would help I do not know.

What happens if you fill the system, leave the cap OFF and run the engine, does the water level rise and pour coolant all over the place?

I had a fairly odd coolant problem last year on a 300tdi and I spend a long time looking at every part of the system including running many tests to work out what exactly was causing the problem, one of the tests included running it with no header tank cap, it did fail this test but after repairs it would run, temp up at about 90°C, without the cap on without problems whatsoever

I didn't want to say it yet, but I suspect it could be HGF between the pot and a coolant channels, in particular the ones that are not drilled in the head, just the block, so they push gas down which sits high and push all the water out of the system. I am concerned that if it was something like this, your dealer is going to do some dodgy cheap fix for you.

could easily be head gasket but check top hose hot to prove thremostat opening,check rad core all over to make sure rad is cooling effectively if only hot down side top hose enters it will need replacing otherwise you will be doing alot of head gaskets ,expansion tanks do split around seem but would seem your problem was over pressurisation from h/g or overheating ,when filling remove both bungs one on rad the other on thermostat housing and fill to overflowing ,this will overflow expansion tank too but it wont hurt excess will blow out of cap and find proper level ,cap has valve that keeps pressure in system to 15psi to increase the boiling temp,above 15psi cap releases pressure

take the opportunity to replace those plastic bungs with brass ones.

sounds a little odd the dealer has said the coolant tank isnt cooling the water as it is only for feed and expansion, i would go with the thermostat stuck or the rad partially blocked,oh and yeah put brass bleds on the plastic ones sheer off

HI
Thank you all for you useful responses. It was clear that the coolant tank was leaking so that has now been changed. No more leaks however the temperature gauge still went up right into the red after 20mins on the motorway. It was clear that the liquid in the coolant tank was not boiling (the new tank is opaque) as it was before. temp gauge stays in the middle on local journeys.

any conclusions?

Follow my instructions for checking coolant flow and stat opening as listed in my first post and you will find the problem or certainly get closer to an answer. You still haven't given us any more information than we started with really. Get more info to us as we will start to come to conclusions.

Have you run it without the stat yet?

If you do and it still overheats then if your dealer says the engine is fine then I suspect the radiator is blocked up. A good cleaning external (fins) and internal might solve this one, it might also cause it to start leaking so be aware a new rad might be needed soon.

Do the following remove rad bung and rad cap fill the rad to the max, check the level in the header tank if its on the cross mark refit the header tank cap then remove stat housing bung and fill that to the max, then test drive if still the same, remove the thermostat and do the same bleeding process, if still blowing almost certainly the head gasket as said above.
Which is just really a repeat of what everyone else has said!
To be honest if it was mine i would be having the head off asap, otherwise could get expensive.
How far away is the dealer as he should really be sorting this out as if you keep driving it he may say its your fault.


Lynall


Lynall

i think you have a blocked radiator but by now i reckon the head will be warped or cracked 300tdis dont like to get hot and by the time the gauge is in the red it's normally too late take it back to dealer tell him you think the heads cracked before your warranty runs out once you tell him the head gone it will cover you even it out of warranty time as it's happened before
all the best

I had a blocked radiator and it's a funny thing, if the wind is blowing directly at your vehicle you may get away with it and it'll 'appear' to be ok.
We took out the radiator (no mean feat as it was on a Volvo Truck!) and jet washed the thing out.
You fire water in through the back-end, not the front. The idea is that any gunge, dirt, crap etc that's buried in the radiator over time is blown out.
Which is why you blast it out through the back-side.
Once we did this it ran fine, no over-heating...
Good luck.

I had a blocked radiator and it's a funny thing, if the wind is blowing directly at your vehicle you may get away with it and it'll 'appear' to be ok.
We took out the radiator (no mean feat as it was on a Volvo Truck!) and jet washed the thing out.
You fire water in through the back-end, not the front. The idea is that any gunge, dirt, crap etc that's buried in the radiator over time is blown out.
Which is why you blast it out through the back-side.
Once we did this it ran fine, no over-heating...
Good luck.

The issue has now been solved!!!

The dealer who has been fantiactic throughout (MG Landrovers, Ashbourne, Derbyshire). Took it back off my hands and checked everything that has been suggested.

There were no mechanical faults with the car but it was found the the wrong temperature sender unit had been fitted.

I drove back with it yesterday, all fixed and even pootled at 70mph for a bit!

Thanks for all your help

Sorry to urinate on your french fries but if you had a coolant eruption the temp sender was right, the engine had a boil on which is what the temp sender said.

Take it back again and ask the dealer to explain the boil and eruption if the cooling is working A OK. He can't.

get a sniff test done on the coolant - somewhere other than the dealer - he is bull****ting!

Similar problem on a 300tdi disco, am I supposed to start another thread?

Symptoms are, pootling down M61 heater works OK, foul weather loads of spray but that's an asside.

About Milnrow on M62 I notice the heater isn't giving any heat and won't even when turned up?

Half way up the big hill the temp indicator is in the red so I pull over. Like the OP the expansion tank has vomited and the inner wing is all wet. I left it as long as I dare to cool and vented the expansion tank with more water puking out. I had some water with me so I filled up the tank then the Highways Agency showed up so I told them I was on my way.

The temp gague was still in the red and the heater didn't warm at all so I limped to J22 and parked up on the A road.

It was hot, water on the rocker cover boiled, quite well.

In the 2 hours it took for the AA to turn up the cooling engine emptied the expansion tank so I topped that up. The AA man put more water in through the radiator bleed and thermostat housing(?) bleed.
When I set off the heater worked fairly soon as the temp showed midle of the range. I managed about 10 miles to the other side of Sowerby Bridge before the heater went cold so I stopped for the AA to tow me before the temp gague went into the red again.

I'll do the thermostat test described above.

I never thought to feel the radiatior, I'll see about that too.

What can I do to test the water pump?

What else should I be looking at?

I realise the head my well be bolloxed but I want to try to cure the problem and then see what other damage has been done.

I got the thermostat out last night and tested it, it's working OK.

I did put it back together without the thermostat and ran the engine for a while but it didn't warm up so well. The temp needle never moved and the heater didn't get warm. The head was warming up and the radiator and pipe along side the rocker cover to the heater got barely aired but since the thermostat worked and the water pump was making a noise I stopped the trial early to look at the water pump.

The water pump got quieter when I put more water in the thermostat bleed point, it was full before I started it up but it took more when the engine was running. The water pump looks OK, ie there is an impeller on it, but the noise it was making makes me think I should fit a new one. I'm not convinced that the water pump is the main culprit as it wasn't noisy before, it was easy enough to hear last night.

I found a 2" lump of what seems to be putty in the middle of the rad about a ¼ of the way up. It may have some bearing but there is loads of rad clear to work the putty covers maybe 3 tubes. I'll take the rad off and flush it out, make sure there is a way through.

What does radweld look like when it's escaped from the P gasket? There is some brown ****e on the water pump housing when I got it off to change the P gasket. Also it's not smooth, I'm hoping I have found my problem. What worries me is that the only puddles on the drive are oil. If it was dripping water I should have noticed somat, it's been dry enough recently.

I'll have to watch the water and the oil like a hawk when it goes back together.