[The ''Tropical'' Modification]

Nigelw...Yes something new for me as well but totally sense...

For us in the tropical southern hemisphere with ambient temps seldom below 10ᵒ C we need more flow through the cores.

The ambient can get as high as 48ᵒ C

[The ''Tropical'' Modification]

With all the advice and brain storming of why my Disco 300 TDi would overheat I came across a very sensible mod.

That is to close the by-pass hole in the radiator. (The so called tropical mod)

If the plastic (should be brass) bleeding plug on top of the radiator is removed and looking down there is a +/- 20 mm hole which will allow water to run straight through.

Surely with the older radiator like mine it will be the case due to silting up of the cores.

Water always takes the easy route !

That means there will be minimum cooling of water and not to mention oil...?

The intercooler next to that will also be affected...?

Ok all good and well but how do I close that hole through a 25 mm hole ????

I am 500 Km from the closest Engineering or Radiator works...

Is there a way to do it myself....Will prattley steel glue last ?????

I might be able to screw something in there...from the top !!

[Introduction of myself and my overheating Disco 300 TDi 1997]

admittedly mines a 200 and run 1.2/1.3bar real boost for 6+mnths and fine so far.

i would probably put money on it that the missing dowel would be the cause of the head gasket failures as with out them head will 'float' about. i would use a composite gasket rather than mls and deffo 3 hole use.

personally i would worry about the warped head, its very minor. ive used sealant on headgassket on a very warped block (4d56) with composite HG with success.

Landy-N....Thank you for advice..I believe the missing dowel played a huge part in my misery...

I want to believe the boost is not the cause although lots of friends (Maybe bit jealous) states that a 300 TDi can do max 0.8 boost without damaging something...

It ran for over a year and 48 000 km on 1.2 boost and then I had a radiator hose rubbed threw by the alternator pulley and my problems started....

Thinking of it...that is the first time and I needed to change the head because the injector was seized and could not be removed...That is were my Dowels has gone..!!!!

[Introduction of myself and my overheating Disco 300 TDi 1997]

you will need the 3hole gasket for sure.

also 2 dowels

I assume you follow up the sequence for mounting the head bold precisely?

be sure the small water hose that runs from thermostat housing to the 3 way plastic thingy and from that to the expansion tank is not blocked, if so, the air can't escape from thermostat housing and thermostat will get stuck resulting in overheating.

been there done that.

and 1.2 turbo pressure is a bid on the limit, would do 1.1.

Disco....Thank you....Yes.. definitely needs the dowels...

Yes the torque sequence was strictly followed .. although I did not do a re-Torque on 2000 km ???

Bought new expansion tank and installed copper three way splitter because the plastic one broke on me the first time the gasket blown...New cooling system pipes installed January

I also thought to bring it down to 1.0 or max 1.1.

[300TDI Head gasket]

In my post Disco overheating Boydie gave some very valuable answers....

[Introduction of myself and my overheating Disco 300 TDi 1997]

OK...armed with my pics and will try to upload..

I have found the head to be seriously warped seriously taking the gap on the straight edge steel ruler.

The pitting from the unused water ports is serious and do not know if there is anything else that can be done except stitching...

[Introduction of myself and my overheating Disco 300 TDi 1997]

Landy Novice....Thanks for reply I will take some pics today

No 1 mistake there is only 1 dowel present but the block isn't warped.

Boydie....You have answered a lot of my questions.

I understand the 1, 2 and 3 hole better now and agree 100%

The three triangular water ports caused serious pitting of the head and definitely 1 of the reasons.

The current head is warped and I am considering a new head (If Budget allows)

The "evolution" head ? is that the so called 2.8 head ?...I can not find a lot of info on this.

(Especially in my 3 world)

Thanks for warning against steel/copper gasket I was already quoting one of these.

Did you close the ports on the block ?....Interesting....!

Is there no channels in the head to open the ports on the head and might get more cooling in the head !!!!!

Can the 1.2 bar boost contribute to head gasket failure ????

Once again Thank you for very usable information....

Let us see if I can be 5th time lucky !

[Introduction of myself and my overheating Disco 300 TDi 1997]

Hi all

Thank you for allowing me on this very informative forum.

I know there is a lot of threads on 300 TDi's overheating and a lot of good advice given.

But after following all the advice, recoring radiator, replacing water pumps, fan and even fitting another recon head and still blow head gasgets...ouch !!!

This is my fourth head gasget in 3 years (2nd this year)

(2 notch gasget) and every time skimmed and pressure tested (new head bolts)

New expansion tank and hoses.

New thermostat working and fitted correctly.

I have installed the VTDi turbo and boost up to 1.2 bar, EGT monitor (Madman) never exceeds 720 deg.

(With the VTDi turbo can drive 120 km/h in 5th gear normal up and down hill roads.)

I do not abuse the truck on off road tracks but use as a holiday and weekend vehicle.

Came back from Inhambane Mozambique and blown gasget at Xai-Xai.

It has 320 000 km on the clock

Things not done on cooling system...Not blocked radiator bypass.

Not removed Aircon Radiator in front of radiator..

Any advice will be appreciated...I Love my Disco...