Thread: Buying Disco 1 with Blown Headgasket 300tdi

Originally Posted by dearot

Hi,

I am thinking of buying Disco 1 with Blown Headgasket 300tdi. How do I check whether the head is warp/seized? How much approx to fix blown head gasket on 300tdi? Thanks.

You will only know if the head is warped once its removed, cleaned and a straight ran across it at various angles.
If the head passes a hardness test, get it skimmed and fit new gasket with new bolts, if you can do the work yourself then about $250 in parts inc head skim but generally you will need to get the other cooling system components checked and or replaced if you want longevity out of the motor.
so budget for around $400-500 or double + for a shop to do it.

A blown head gasket in a Tdi300 is usually the symptom of another problem. ie. failed P gasket, leaky or blocked radiator or failed viscous coupling which has led to serious overheating though you can be 'lucky' and have a head gasket that has just rotted away around some of its 'holes'. Often a failed head gasket is accompanied by a warped or cracked cylinder head, you're not really going to know until the head is removed. If the seller tells you that it's definitely a crook gasket and the head is OK he is either an idiot or a liar and I'd be very careful of buying from him.

To help gauge the degree of damage the circumstances surrounding the failure need to be known.

ie. scenario 1. ........................... Owner started engine and noticed overheating or water escaping under pressure and turned it off. This is the ideal 'blown head gasket' scenario, chances are the head is OK as the engine hasn't been cooked. The problem here is that the owner may know this so is telling 'porkies' about the circumstances .

scenario 2. ............................... As above but the owner (whose other car is a beat up VR Commodore) decided to remove the thermostat (or replace it with a non bypass Holden type) to help resolve the issue as he is Gods gift to mechanicing. Unfortunately the engine is now ruined as there has been nothing to regulate the coolant flow in the head and it is now stuffed .

scenario 3. ............................... As in scenario 1 but the owner has driven it home 20 Km from the beach in summer, refilling the coolant along the way also ensuring that the cylinder head is possibly ruined .


So 'buyer beware'.

The cost of repairing the initial problem as well as the head problem and whatever other items need fixing for roadworthy make even scenario 1 a potentially expensive exercise.

IMO, to make this a worthwhile exercise considering the financial risk and work required the Disco would need to be in otherwise mint condition and come with a years subscription to AULRO (or Playboy) , whichever takes your fancy and be very, very cheap (a couple of hundred max.)

Deano

Just be aware , Sometimes it's not as easy as just the head and gasket, we have had a couple customers with blocks that were not true, and after fitting new heads and gaskets blew them straight after, some times running a straight edge over block is not accurate.

Thanks guys.

Another thing I need to ask is there a different between 300tdi in discovery auto and discovery manual?

Originally Posted by dearot

Thanks guys.

Another thing I need to ask is there a different between 300tdi in discovery auto and discovery manual?

Engine is the same.

Originally Posted by loanrangie

Engine is the same.

No ecu or electronic controlling the engine on disco auto?

Originally Posted by dearot

No ecu or electronic controlling the engine on disco auto?

Nope.

Originally Posted by pop058

Nope.

I read on internet most of Discovery 300tdi automatic used Electronic Diesel Control (EDC). It says most so not all. How do I check this? Thanks.