Broke down today

[cardiff_gareth]

Hi guys,
Just to add to the 'to do' list I broke down on motorway today.
I knew something wasn't right as I had no heat coming through the heaters, even when playing with the heat settings. Then the temperature gauge went up high. Stopped straight away and turned off engine to avoid cooking it. After about 5 mins, started back up and off I went but only got a bit further down the M4 until she went into 'hot' territory so stopped again. Left it about 10 mins then restarted and went to limp into services as they were about 2 mins away from my location. As I get into services heat resumed and temperature came back down again  
Do you think dodgy thermostat or air lock in the system  
What would be your course of action. Disco is used daily so can't have it laid up on drive  
If an air lock can it be bled and what is the best way to do this  

DOHHHHHHHHHHHHHHHHHHHHHH

[Range Rover Blues]

Quite possibly an air lock but you need to be sure.

So start by checking if it's used any water, low coolant could itself cause an airlock.

[cardiff_gareth]

it was ok as I topped it up about 3 weeks ago as low. I just plonked the pre mixed coolent into the header tank. Will re-check tomorrow. If its low is there a way to bleed the system ?

[Range Rover Blues]

If it's a V8 then depending on year there will be a brass plug on the pipes at the top of the negine.  Fill it here to avoid air locks (see, even Rover knew this would happen).

On a TDi I'm not as sure.

What I like to do is fill it right up whilst cold, then run the engine and as it warms up water will be forced out, so I open each fillerplug just a little to let the air out.

I also find that fresh water can sometimes produce air from no-where, so I use boiled water in the header tank, the boiling forces the air out.

[stageonesimmo]

If its a 300 TDi.  When its properly cold - first thing in the morning.  To check the coolant leave the expansion tank cap on and undo the filler plug on the top of the thermostat housing - it SHOULD be full, if its not fill it till it is - don't worry about the level it will stay put as long as you leave the lid on.  Then with the plug back in, check and remember the level - if its too low top it up a bit and remember where it was (I use the seam of the expansion tank as a gauge as I cant for the life of me see the daft 'X' shaped thing in the tank) then drive it as normal and see what happens......

[Range Rover Blues]

On mine the x thing is level with the seam anyway, it's becasue of how it's moulded.

I had to chuckle once, a 'mobile mechanic' once told me that the circular tube throught he centre of the tank was a good way to tell if it's full, you touch the bottom of it, if it's hot then there's water, if not then it's running dry.

Usefull?

But recently another 'mobile mechanic', IIRC the one with the flashing lights, told me they put that 'kiss throug' into the tank for exactly that reason.

My big hairy butt, it's there to stop the tank blowing up like a football.

[cardiff_gareth]

Well short of time this morning so I undid the header tank cap, heard a trickling noise and then a hiss as it de-pressured. When looking in couldn't see any water so filled her up slowly. She took exactly 2 litres of water. Whilst there I gave all the hoses a good squeeze and checked the oil level and under the oil cap for white scum but nothing so at least thats one thing I can rule out.
In work now and no overheat on the way in, not sure if paranoia but it seemed to run a bit better / quieter and heaters worked very well, too well   :lol:  :lol:

Do I check the bleed plug on the thermostat or leave it as not to rock the apple cart :?:

[Lyndsey731]

You need to ask yourself why it needed topping up again when you only did it three weeks ago and why it was still pressurised after being left overnight?
James on here had the same problem, fine driving around town but would overheat on the motorway, his was the head gasket.

Gav

[cardiff_gareth]

That was my concern, that the head had gone but I get no smoke from driving, oil is black not creamy and also there is no scum under the oil filler cap. Can the head go without these symptoms  :?:

[Lyndsey731]

James's ran sweet as a nut and the oil was fine, no white at all and no smoke. Run the engine with expansion cap off, be careful obviously and see if your getting any small bubbles coming up, thats a pretty good sign that all is not well. With James's because the crack was between the chamber and the cooling ducts in the block if you revved the engine with the cap off it was like a fountain inside the tank as the gases were over pressurising the system.

Gav

[Wireless]

Get underneath and check that the core plugs aren't leaking.

Had a similar journey recently, with no heating and a rapidly variable water temperature level, turned out to be a core plug with a pin hole perforation, rusted through from inside out.

Unusual because the coolant has always been within specification, so we removed a second plug alongside it and found that to be perfect.

Land Rover must have had some parts delivered to it which didn't meet specification, but you can't tell from visual examination, and as mines getting on for 11 years old, Land Rover would just say 'tough'  :(

[Lyndsey731]

Gareth, what engine do you have there mate?

Gav

[cardiff_gareth]

Its a 300TDI.

Whats a core plug and where would I find them :?:

I know it had a hell of an oil leak but it slowing now, it was really over filled when I bought it but the oil level is now fine. It was leaking or pumping out the oil from I think from the crank breather by the rocker cover but it may be blocked as it has congealed oil there. Who ever had it before me I think has done work on the engine as it has many new parts on it and also the bendable oil pipe that goes into the breather that normally sits at the rear of the engine is resting on the rocker cover :?:
Will check water level again when I finish work but that'll be at about half 4.
I do the same drive every day so its not like it was out of the ordinary for it and never had a problem, just yesterday :?:

[chris.hunt22]

Mine did exactly the same, check your front carpets for being wet under the mats, if so heater matrix i'm afraid :shock:

[cardiff_gareth]

Mine did exactly the same, check your front carpets for being wet under the mats, if so heater matrix i'm afraid :shock:

Front carpets have been a bit wet but I put it down to a front sunroof leak, whats the best way to check, put rubber mats down :?:

How big a job is the heater matrix to replace then :?:

[Thrasher]

*NIGHTMARE* ;-)

Sniff carpets - if it smells of anti-freeze - it's a leak, if it smells of wet dog, it's rain.

[cardiff_gareth]

I defeniatley smells of a long hired dog  :lol:

[DiscoCWK]

Hi Gareth,

My Disco 300TDi used to overheat under load - motorway driving in particular.

The first thing I had done was have the whole system flushed and it ran ok for a small while.

Then it began again. The problem was that the system would get pressurised under load and push water out through the expansion cap - the water pump on the 300tdi is at the top of the engine and it doesn't take much of a drop in water level to stop circulation and then overheat. I did a huge amount of research on the internet and that led me to believe that the headgasket was gone. It is possible on a 300 tdi for the headgasket to blow between a cylinder and the water jacket the pressure is high enough to prevent water getting into a cylinder and create steam and as no break exists between the oilways and the water then there are no milky deposits.

Anyway, I had the Head gasket done and it's now fine - You need to be aware that the heads can only be skimmed a small amount, but you can get thicker headgasket (they are marked by small holes - 1 being the thinnest and 3 being the thickest) You can compensate for the skimming by using a thicker gasket. I would also recommend getting the head pressure tested and checked for hardness (If they go soft they will keep warping)

I hope your problem is not the head gasket, but your problem sounds identical to mine.

[cardiff_gareth]

how much does it cost then if the head has gone  :?:

[DiscoCWK]

I would budget for around £650 from your local trusty mechanic.  

[DiscoCWK]

Well this thread has turned out to be the kiss of death!

I came home from work with the intention of giving the disco a run out tonight as wednesday is pub night!

I noticed that the ground under the disco was wet. I started her up and coolant was dripping off the underside of the gearbox and the exhaust. I took the soundproofing off the engine and the connections from the top hoses to the bulkhead are sound and completely dry. I then notice water is dripping from the soundproofing on the bulkhead to the exhaust and I assume that this is dripping onto the gearbox aswell  :(

It looks like it's the heater matrix  :x (can it be changed without taking the dash out?????)

I had a feel round the back of the engine and it seems dry, so I cant see it being a core plug. If anyone has experienced the same let me know  :?:

[cardiff_gareth]

You trying to make me feel better :lol:  :lol:

Well I went to the Disco after work and checked the coolent level, this hadn't dropped so I left the header tank cap off and started it. Ran it for about 5 mins and no bubbles appeared. Drove home, no worries.
Does that mean i'm in the safe or not.

Having looked further it appears that it has a new radiator, new thermostat housing and what looks like a new gasket on the water pump :?:

[DiscoCWK]

Not trying to make you feel better!

Try revving it with the expansion cap off and see if the surface of the water is disturbed by a jet like affect.

Anyway saw the chap (has his own MOT/Service/Repair garage) who fixes the major things on my disco (like the headgasket) in the pub tonight and hes confident he can sort it for me next week without removing the dash!

Maybe not the heart-ache I was expecting!

[cardiff_gareth]

Well, did my best with a torch but started engine with the header tank cap off and ran for a few minutes, then revved the engine but not to hard as it was cold still but nothing in turns of bubbles or jet effects, just a cool pattern that the vibrations made on the surface  8)
What else can I try to see if head is gone or do you think it may be something else. Should I be leaving the engine to heat up more before revving or is there no difference to this, just get worried running with no cap on for too long :lol:
Hard to do the test with the engine oil filler cap off as tensioner is chirping like a flock of 1 billion budgies  :oops:

I heard a rumour off a guy in Cardiff that the heater matrix can be changed without removing the dash  

[J13 MUD]

I had exactly the same problem with my 300TDI recently, tried everything, it would be fine for a while then overheat again. The RAC guy was certain it was just an air lock but alas no. I took the head off and found the problem to be a pin hole in the gasket by number 4 cylinder, changed gasget and all cylinder head bolts and problem cured.

Just one slight correction on a previous post, skiming the head makes no difference to the gasket thickness, the thickness required is dependent on the protrusion of the piston above the block, whatever gasket it has on when you remove the head should be replaced by the same, just check the number of holes on the edge of the gasket, they can be seen before removing the head just behind the fuel pump.

[Lyndsey731]

Gareth, I hope it was nothing more than an air lock as it has settled down, being the suspicious type though it looks to me like someone has tried everything to fix an overheating problem and not suceeded, hope i'm wrong mate.

Gav

[chris.hunt22]

Just to see if its the matrix....it's a bit sick but touch the wet bit of your carpet, if it tastes sweet its antifreeze, might not nessecarily be the matrix itself but you know its getting in the car somehow, mine started losing about a litre a week (about 50 miles or so), I kept topping it up then noticed the carpets were sodden, was getting worried when I could see steam rising around my steering column, I have blanked the pipes off for now until I have the time to do it

[cardiff_gareth]

Gareth, I hope it was nothing more than an air lock as it has settled down, being the suspicious type though it looks to me like someone has tried everything to fix an overheating problem and not suceeded, hope i'm wrong mate.

Gav

I know what you mean, it's had a lot of work done to the engine and all to do with the cooling system, saying that it does have a new vacuum pump as well. I located the previous owners address last night so going to pay him a visit later today to say 'hi, remember this'  :lol:
Might get to the bottom of the riddle.
It's weird its running fine now and coolent level is still ok.

Just to see if its the matrix....it's a bit sick but touch the wet bit of your carpet, if it tastes sweet its antifreeze, might not nessecarily be the matrix itself but you know its getting in the car somehow, mine started losing about a litre a week (about 50 miles or so), I kept topping it up then noticed the carpets were sodden, was getting worried when I could see steam rising around my steering column, I have blanked the pipes off for now until I have the time to do it

I'll lick my carpets tonight  :lol:  :lol:

Just hope that it was a random air lock and nothing more serious, i'd prefer a dodgy heater matrix to a new head gasket :?

[cardiff_gareth]

well I decided to check the log book for the previous owner and pay them a visit to find out why all the engine work. Turned up there and the guy was like 'I recognise that :shock: '
Got chatting to him and it appears that he bought it for his building business, to cart stuff around too and fro. The guy said he has spend near on £2000 on getting the engine rebuild. He overheated it and warped the head so its had a new cylinder head, new head gasket, new pistons + rings, new radiator, new thermostat and new cambelt. All done 6k miles ago. Spending all that money on it I can't see it being the head gasket :?:  if so, he got ripped off :!:

I checked the water level again today and its not budged, tried the bubble test on the expansion tank and that came back with no bubbles, even with light revving. Did it yesterday as well but did it again for my own peice of mind.

Best thing about it is that he still has the FSH for it so I'm picking it up 2moro or Satuday, sweet  \:D/  \:D/  \:D/  \:D/

Oh and fitted the new colways today, 245/70R16's. Looks good and handles much better, cornering was weird as I nearly went up the curb as I now need to steer more  :lol: