300tdi overheating and not de-pressurising.

[redneck.woman91]

Hey everyone,
does anybody have a suggestion as to what could be causing my 300tdi defender to majorly overheat? And also why sometimes it doesnt actually overheat but it just wont release the pressure from the radiator and tubes, even hours after the utes been turned off?

We had to replace the head gasket because it blew around 6 weeks ago (not causing any other issues except for a funny noise and crappy fuel economy), and up until the last week everything has been fine. Then Dad noticed it wasnt de-pressurising after i turned the ute off, but there was no sign of overheating or sluggishness.

On Wednesday she overheated BIG TIME. I noticed a burning smell for a minute, and while I was trying to figure out where that was coming from, the temperature gauge shot off to the end of the red.
After pulling it up, opening the bonnet and waiting 15 minutes for the grumbling, gurgling and steam to stop, I undid the top coolant reservoir and noticed it was now bone dry when it had been full when I left home, and the head and my radiator tubes were all boiling hot.

When Dad came to rescue me off the side of the highway 4 hours later we filled it up with water, and managed to get it another 10km before it started to overheat, so we pulled up again. Dad checked everything, my coolant was barely lukewarm but my head and tubes were boiling. We figured we would disconnect the thermostat (a trick we learnt with another overheating 300tdi) and limp it home. What do you know, the thermostat wasnt opening. Once we pulled it out, we got it home and the head, tubes, and coolant were lukewarm/almost cold. We figured that the thermostat therefore must have been the problem, so we got a new thermostat and after putting it in Dad drove it everywhere today. It was running a bit hotter than usual (at normal operating temperature it was on halfway on the temp. gauge where before it would have been at a quarter.) and 3 times jumped up to the end of the white line, but then very quickly went back to halfway. We thought that was a bit odd, but other than that everything was working fine, and coolant was luke warm at all times.

The bloody thing overheated big time again this afternoon, dumping coolant on the road and hitting the edge of the red on the temp. gauge. We disconnected the thermostat and got about 1km down the road before it overheated again, then we had no issues to get it back home.
Can anybody please explain what the hell is going on? Because if this keeps going i will have to sell it :(

[GuyG]

What sort of condition is the radiator in? Has it been rodded recently?

[roverrescue]

Me be thinking your still getting combustion gasses and water jacket sharing the love. Your symptoms all sound very head gasketty!

-Was the head level / skimmed before replacing gasket?

-Was the deck level and clean before fitting?

-What gasket did you use in the replacement?

S

[redneck.woman91]

Hi there :)
Radiator is around 18 months old if that, and pretty clean. Theres a few bugs and a bit of mud on it but nothing substantial. And yes its been rodded :) Checking the radiator was actually the first thing we did when we pulled it off the road to do the new head gasket lol.

Yes the head and deck were both level and clean when Dad put the new gasket in, he was very careful about making sure there was no damage done to it as he thought maybe after 15 years and a stuffed head gasket, my head could have been wrecked.
We got 1 of these new German metal gaskets from a 4wd parts supplier in Newcastle, and we were both a little concerned about that lately as we have been told that could cause an issue?

[Blknight.aus]

sounds like the head to me but it could also be the waterpump impeller failed or the VC not transmitting drive to the fan.

leave the filler plug off of the thermostat housing and start it up.

if theres no coolant flow its the pump

if the fan spins on for more than a second after shut down its the VC

if as soon as you start it up its blows coolant out the filler its the head.


Thats not exhaustive but a very quick indication for worst case scenario for all 3 items.

[justinc]

Regarding those metal shim gaskets, i never use them unless on a newly machined block surface, I have had 2 leak in the past and after switching BACK to composite gaskets (Elring genuine type) I have never had another issue. I won't use them now.

I think that your symptoms best describe another head gasket leak. At least they are easy to remove/ refit.

JC

[redneck.woman91]

So it could be that gasket??
We have used one of them at least once on our old Discovery, and we believe they were used another 2 times on the same vehicle with different mechanics, becasue they are cheaper and easier supposedly..... the whole time the Disco had the same issues as my ute and in the end Dad gave up and sld it for scrap after the gasket blew again after 3 months.
I dont want to lose my little ute, so I hope the head isnt damaged :(

[Blknight.aus]

for the metal shim gasket to work properly you need the deck and the head face to be perfect AND to have the correct surface finish, the elring gasket kits are a lot more forgiving.

IF it was me, my next step would be to pull the pump pressure flush the radiator replace the P gaskets and have the head crack and pressure tested. IF the deck and the head are ok Id then be putting it all back together. At this stage if its a gasket mating problem its likely you can save the head if you get on it promptly.

[redneck.woman91]

The P gaskets were replaced 1500km or so ago when Dad remembered to haha. Will do with the radiator, I think its OK but Id rather be sure.
Around here we have nowhere to send the head to :(

[Blknight.aus]

given that....

how goods your workshop gear, I can probably talk you through how to build a pressure test jig for doing a cooling system pressure check while the heads off.

your going to need some 3-5mm flat plate
something to weld some angle iron onto the back of it
some decent angle iron
something to drill some holes in it with
some 5-10mm rubber sheeting
fittings to seal up the head and apply pressure to it
something to heat the head up to 80 degrees with (the kitchen oven or a bbq oven works well)

if you dont have a decent engineering straight edge (and no, I dont mean a steel rule) you can improvise it withe a lot of patients, some feeler gauges and a laser pointer.

[Bauke]

do me a favour check that the little hose from the thermostat to the water tank isnt blocked at the little plastic y peice

[redneck.woman91]

Hmmmm... Havent checked that, yet I will have a look tonight... Could that also be causing this?

[Blknight.aus]

it can if its preventing the cooling system from purging correctly.

without the purge line letting the head bleed correctly you can wind up with hot spots in the head that then flash boil the coolant as it circulates....

[justinc]

...the air has to get there in the first place...I think the head gasket is leaking.

:(

JC

[redneck.woman91]

i think yuo may be right there, it seems very head gasketty. Hopefully the gaskets all thats stuffed and i didnt damage the head or my little rover will be stripped for parts nd Ill have to get one of those other crappier makes of vehicle lol

[redneck.woman91]

i think you may be right there, it seems very head gasketty. Hopefully the gaskets all thats stuffed and i didnt damage the head or my little rover will be stripped for parts nd Ill have to get one of those other crappier makes of vehicle lol

[Blknight.aus]

orrrrr, you could just get another head and bolt that on....

[redneck.woman91]

That is sadly an expense I cant afford... darn landrover's sent me broke haha. Any money I made offf the parts would go towards a car and even then probably wouldnt have enough.

[Blknight.aus]

get a fleabay one...

I wouldnt trust it for hard usage but for normal soccer mom stuff it'd do.

[redneck.woman91]

lol she doesnt just get the soccer mum crap when my parents drive, she's also a BNS ute, our farm runabout and a mean 4wd whenever I get the chance to pack up and head off... usually has to travel around 500km trips at a minimum once a week to do the shopping as we live a long way from anywhere...
am not sure a fleabay one would withstand it. How much would I be looking at for a decent one if Dad and i put it in?

[wrinklearthur]

lol she doesnt just get the soccer mum crap when my parents drive, she's also a BNS ute, our farm runabout and a mean 4wd whenever I get the chance to pack up and head off... usually has to travel around 500km trips at a minimum once a week to do the shopping as we live a long way from anywhere...


am not sure a fleabay one would withstand it. How much would I be looking at for a decent one if Dad and i put it in?

Hi RNW91

Send an enquiry to Turner Engineering in the UK.

Cheers Arthur

[Blknight.aus]

I'll have to price one out from MR automotive...

the fleabay ones are a bit hit and miss but you can get a good one...

turner engineering in the uk does them at around $700

Land Rover TD5 cylinder head LDF500170, LDF500160, 300TDI cylinder head, 2.0TCie Freelander cylinder head LDF107830L, 2.5 & 2.5TD new short engine assembly and cylinder head, STC 803, LDF109390L 1.8 Freelander petrol cylinder head, crankshafts 300TDI (http://turner-engineering.co.uk/html/specialoffers.html)

Cylinder Head Assy for Land Rover Discovery 1 300Tdi - LDF500180 - 1994 (http://www.land-rover-parts-shop.com/en/ui/products.php'model=Discovery%201&engine=300Tdi&cattext=Engine&subcattext=Cylinder%20Head&group=Cylinder%20Head%20Assy&year=1994)

[redneck.woman91]

Thank you for finding those for me :)
Dad is nto keen on putting more cash (other than gaskets, studs, etc this time) into the 300tdi motor. His original plan while he owned my ute was to eventually swap it over to V8 on gas, but entirely on gas with bigger tanks so it didnt matter what V8 we put into it. He wasnt sure how he was going to go about this, but would anyone here have an idea? Becasue if Im already going to have to get a loan out to buy a new vehicle, Id rather punch the money into putting a new engine into the Defender and getting my 300tdi woes over with. Dad thought it would be around 4 or 5 thousand just for the gas system, but then we have to sort out the engine.
Does anyonehave any suggestions about this and is it a worthwhile plan?

[isuzutoo-eh]

Seeing as you don't live in Peat's Ridge anymore, is LPG easily available on your usual coupla hundred km treks?
Get your head checked before spending too much, it may be okay and its only a gasket needed.

[JohnF]

Hi I overheated my 300TDI, and did no damage. do not expect the worst until you have the head off.

http://www.aulro.com/afvb/technical-chatter/131931-overheated-300tdi-plus-question-plug.html#post1510172

[redneck.woman91]

Just looked at the head, it isnt warped :) actually theres no damage at all to the bloody engine..... it still starts and runs fine. We are going to put a new Elring gasket on, and hope that solves the issue for now. We are also replacing the head bolts as Dad thinks they are a bit shot now, the heads only been off once before but the bolts are a bit shoddy.

And we can still get LPG at our local servo (45km away), but if its not working we have to go another 150km to get it lol.

I would like to look into doing the V8/LPG idea, and then if the ute runs fine after we have put the new gasket on then I will keep the V8 idea on the books as a in the future idea.

[redneck.woman91]

W have been told that for everything to work correctly this time around, we need to get the head machined... im sure that wont be cheap... bloody landrover is sending me into the poorhouse lol but its worth it if she works how she should again.

[justinc]

A good machine shop should be able to reface it for less than $150, and that should be returned to you in a clean ready to bolt on condition.

Always blow out all the ports and galleries yourself though, just in case:(

They are a fantastic simple engine, I wouldn't swap it out for a V8 petrol engine, especially on gas.

Diesels rock.

JC:D

[Blknight.aus]

the last time I did a total rebuild (at cash mates rates not beer rates) for a tdi300 with the owner doing the runaround and organising the parts he was instructed to buy he got change from $3k for a complete rebuilt engine using his old engine and replacing pistons, rods, bearings, head (complete), pumps, (not the IP)mounts and reworking the radiator.

he then decided to fork out for a new clutch assembly which ment he had to get a new flywheel, the old one cracked during refacing.

if the bottom ends ok you can replace the head for less than $1k.

[redneck.woman91]

So far so good.... we had a retired mechanic come out last night and have a look and as far as he can tell, no damage has been done. His idea was that the head bolts have stretched too much and that may be a cause of the overheating and issues. He thinks the heads been off more than the once Dad and I knew about while we have owned it in 15 years, Dad was second owner and the first guy had it for a year and a half.

[Blknight.aus]

a ready to drop in head (complete + assembled with valves, springs, rockers, supplied with headgasket and bolts) will cost you about $1800 from MR Automotive.

the head gasket is something like $60 and the bolt kit is about $80

[redneck.woman91]

Cool well in the event that i need it, thats where I will be going to :) Thank you for searching that out for me

[Hally]

Just another thought.

My tdi300 used to do this and then it also happend to me when I dropped the 4.6L V8 into it. The expansion tank gets old and the cap no longer hold pressure so it would slowly over time leak water which made me think I had done a head gasket until one day I was Accelerating and noticed a bit of coolant came out from underneath the bonnet and the temp gauge went straight up, I pulled over as quickly as I could turned it off and checked the expansion tank it was bone dry. Got it towed home asked a million questions on here and spoke to MR about it and they said this is a common problem with the old black expansion tanks so I bought a new one off them and havernt looked back. my tank was about 9years old when this happened.

Good luck hope it doesnt work out too expensive.

[redneck.woman91]

That is something I thought may have been the issue.... How much was your new Tank? I think that will be my next task lol I dont want to take any chances