How defeated are we!! Bleeding air from Rad

My mates 300TDi N reg. Has been over heating so I thought it's got to be an airlock somewhere.
Broke down "we had to stop 5 times to bleed the excese off"
Tonight he topped her up with 3 Ltrs of water, blead it from the Brass nut on the thermostat and the header tank lid shut.
Pushed air from the two main water pipes to the rad and replaced all the caps.

Sealed tight,, right!!

Turned her over for 2-3 mins and water started to pi$$ out of the header cap "well that means over pressure of the system" good job the cap works, but is there still loads of air in there.

We have put at least 5-6 litres in since saturday, so it must be doing the same thing and coming out of the cap and i don't think it's got to the HG stage yet. "I HOPE"

I'm just thinking that there is a massive amount of air in there we just can't get too.
Were about to replace the water pump with a genuine one £40 as when his Alt went he replaced it with one from 4X4 direct and had his brother in law fit it.

Well when it came to replace the knackered water pump and tensioner we had trouble getting the belt on, so we scratched or heads.. bought a bigger belt and was better.

I realised the pulley on the Alt was bigger by 12mm I think so hence the new water pump soon.

Would knackered bearing in the water pump reduce the water flow and let the water build upto steam and push the water out the header tank and reduce the effientcey of the system

Any Ideas..

Sounds similar to mine a year ago - proved to be the cylinder head gasket! Head skimmed and replaced and never looked back.

So you think it could be the gases coming from the head. it's a newish engine as he killed the other one.
Tensioner went on the belt and the water pump didn't move. kept driving and bam siezed engine and £1700 later he doesn't want to hear this.....

Oh dear someone else tell him please!!!!!!

Have you checked the rad, especially the oil cooler part, thoroughly?

I had a problem with mine, Local stealers [1] did a head, didn't work, did a head+ skim etc etc still didn't fix it, they said it looks like a new engine .. took the rad cover off so I could have a look and all the back was blown through ... no cooling fins on the rear at all, so the oil just kept getting hotter and hotter and (I think) boiling the water before it could be pushed through the system, giving very similar pressurisation of the system, symptoms.

Last ditch, I know, but might be worth it!!

[1] Got all my money back off them except labour to fit a new rad that I had sourced ... they hadn't even checked the rad ...

now that was lucky, bloody lucky Paul
I know the rads a bit dirty so will need to check like you said. would make sense, you just have to be lodgical with these bloody things eh
But it does sound like an airlock. after we broke down and took the pressure off and lots of gurrgling she would either get hot straight away or sit nice for a few miles then rocket up and we would stop.

Do it again and would be ok.
We'll just have to see

Ta all

heggars said:

But it does sound like an airlock. after we broke down and took the pressure off and lots of gurrgling she would either get hot straight away or sit nice for a few miles then rocket up and we would stop.
Do it again and would be ok.

Click to expand...

That's exactly how we got home, towing a caravan, from Bridlington ... stop, wait for it to cool, fill with water, start again and it'd either blow straight away or it'd last a few miles, didn't seem any rhyme or reason to it.

The worst part is that the 300tdi is usually such a bloody good reliable workhorse! Mine had done 155k when it happened - my son visited and borrowed it - yeah, you can guess he got 100k down the road AND!!!!!! He still feels bad about it! Good excuse to do the timing belt and fit new pulleys though. Pauls right though - check the simple things first before committing!

I feel sorry for him.
Were just about to replace the water pump for a second time, hes on his 3rd Alt belt, one his second Alternator, Second engine, and about 60 litres of water.... nightmare.

Cheers for the "My mates a dumb sh*t and don't know what he's doing routine" Heggars. The Disco in question is mine lads. Its been problematic since the engine change (Heat seized on the A1 - tensioner went, thought the Alt had died cos only the bat light came on, so kept going to try to get closer to home before stopping),

This afternoon I have ordered a new water pump (as Heggars said), thermostat (in case thats sticking), air return pipe (its looking a bit ropey) and a coolant temp sensor (cos the old one has broken away from the metal thread so you can just lift it out). All for under £80, I reckon its worth doing just for peace of mind more than anything else. I'll try to check the rad tomorrow if I can get out of work for a bit.

One thing I did notice this evening is after the water p*ssed out of the header tank. I left the lid on the header, released the pressure by taking off the brass bolt on the thermostat, then I took off the plastic bolt out of the top of the rad. THE RAD WAS STILL FULL!!! It looks like its just gathering air in the top of the system.

Any more ideas anyone? HELP.

If your in it for the long haul with the disco, Nev, then you'll get a lot of enjoyment out of it and all the f***ing about will still be less dosh than depreciation on a new one! I curse mine on occassions but I still get loads of pleasure from it in return.

I had a very similar problem recently... Changed the stat, water pump and cleaned through all the hoses (and on the recommendation of nickh75 I cleared the blockage in the tiny pipe that goes from the stat housing to the header tank) and to no avail. Took the head off and the gasket had blown and the head was warped. All good now (touch wood) although I always have one eye on the temp gauge!

I hadn't been under a bonnet for nearly twenty years and found it not too difficult a job and very rewarding. In all it took me about 3 hours to take it off (including two trips up to a mate to borrow the sockets that were missing from my tin) and the same to get it back on. The Haynes manual was useful but google it and there are some really useful step by step guides on line with advice that's missing form the book.

My new motto, it's not yours until you've got Landy Juice up to your elbows!

Good luck and HAVE FUN!

Further developments!!!!

Spoke to a mate of mine who is a bit of a whizz with cars. He got me to make sure all the water levels were correct, with no airlocks etc, then take the header tank cap off and start the engine. He reckoned that if the head gasket has blown then the water should start bubbling up in there. Well, guess what, it didn't bubble, it came gushing out!!!!

So looks like a new head gasket guys. Heggars has already spotted a good step by step guide (with piccys) to help us. The only thing that concerns me is having a warped head. Is there a good way to tell if it has warped and needs skimming?

I'm gonna fit the other new parts I have mentioned previousley at the same time, so we'll see how we get on.

You can easily fool yourself into thinking it isn't warped but for what it costs and once you've got it stripped, may as well make a proper job and get the head pofessionally checked and skimmed if required - you can then sleep at night!

Or if you've got a really good straight edge, turn the head upside down (after taking off the valve cap things and storing them carefully in order) and lay the edge all over the place with a light behind. You can use a feeler guage to see how much it's warped. If it's overheated a couple of times it'd be a stoopid man who'd put money on it not being warped.

I paid £40 to get mine skimmed and they turned it round the same day.

I'd recommend a genuine Landy head gasket and head gasket set, the head gasket is multi layer and metal. Very shiny. And new head bolts.

Good luck!

Spoke to a company that does skimming today and he said he could do it for £20 - great. One problem though, he said if it has hardened steel inserts, they need to come out before he can skim and he would grind them seperately. I need to do that if it does. Does anyone know if disco 300tdi heads have them? If so how do you get them out?

the only thing i have removed is the injectors heater plugs and the locator rings but they normaly stay in the block

You'll be pleased to know I have stripped the head without too many hiccups, took me 4 and a half hours though - it was my first time!!! The head is at the machinists and i'm picking it up in the morning. There were no hardened rings in it, so once the injectors and glow plugs were out it was ready to go.

Heggars is coming round tomorrow to give me a hand putting it all back together, so we might be a bit quicker. Hopefully my luck holds when we are refitting it!

The head is now back together after a few hiccups. Just need to fish off in the morning and get her running. Here's hoping

Why you got fish on it? You bin in the river?

feels like it. my hands were so cold today, even with gloves on. the front bolt that holds the rocker on decided to strip the tread out of the cyl head. not good, but we but two nuts on a tightened it until it bit into the head.

Just wondering if the one of the 5 bolts/nuts that hold the rocker on was lose, would it **** it up in anyway.
There is no movement on the cams though....
Just got to change the water pump, a few water pipes and put the air intake pipes on, fill with water and oil...

Should work out