300TDi Head Gasket Question

[RichardAllen]

After loosing coolant (forgot to do up a hose clip up doh!) and overheating I now have a whistling radiator cap. The coolant system seems to pressurise as soon as the enigne starts up. Then the radiator cap starts a low whistle until I turn the enignine off when it continues for a few seconds, then stops. The system is still pressurised though. Even when starting from cold it pressurises straight away. Once the engine warms up, a whisp of steam come from the cap,and after a while coolant definitely seems to be lost. Temperature gauge goes hot sometimes, then cools down then gets hot again, likewise very variable results from the heater.

Can this be anything other that a head gasket - (I have done not a compression test yet) ?

[TD5 power]

hi

you could try bleeding any air out but i wouldn't hold out much hope, could also try putting a pressure gauge in the cooling system to see if it goes above 1 bar to eliminate a fault with the tank cap not sealing. But it does sound very much like a head gasket failure.

matt

[Les Henson]

If there was air in the system - it wouldn't pressurise until the water/air started to get hot enough to expand. I would say head gasket/head warped (get it crack tested at the same time).

Les.

[Les Brock]

Warped head most like.....guess how I know

[RichardAllen]

Head very bent. New one ordered from Turners.

Attached to the back of the head is a small P clip for the oil breather pipe which also supports a large white barrel shaped electrical connector, one wire in, one wire out, it's difficult to trace these wires, so anyone know what this connector is ?

[simonb]

Head very bent. New one ordered from Turners.

Attached to the back of the head is a small P clip for the oil breather pipe which also supports a large white barrel shaped electrical connector, one wire in, one wire out, it's difficult to trace these wires, so anyone know what this connector is ?

IIRC its a white/red coded cable which is the starter solenoid feed cable.

[western]

Found thses in my LR RAVE info electrical section 300Tdi

[Mo Murphy]

RAVE, Ralph ? Have you put the books away and joined us in the 21st century ?

Mo

[western]

RAVE, Ralph ? Have you put the books away and joined us in the 21st century ?

Mo

still got my paper books too

[RichardAllen]

Thanks guys, that connector looks like just the job.

Another question on replacing the head - how clean should the block be, before I put the new head on. I have removed all the old head gasket and given the top face a good hand rub down with a fairly fine scotchbrite pad + WD40, and it is smooth to touch all over, but you can still see staining.

Do I need to keep going and get all the stains out, or is smooth to the touch good enough ?

[western]

nope, that's clean enough, just give it a final wipe with a clean non-fluffy cloth before placing the head gasket on the block face.

[Les Henson]

Non-fluffy? Lint-free in fact. The staining can't be removed without a deck skim, which is generally not needed. A deck skim is usually only required if water pitting in the metal might cause premature gasket failure/re lining. Make sure the head gasket is properly located, the head bolt threads are clean and clear, the bolts themselves are clean (if you're using the old ones). No threadlock, no gasket sealant - gasket to bare metal both sides. Follow the torque tightening/angle sequence religiously, and definitely don't give the bolts that 'liitle bit extra-just to be safe'. The procedure for replacing the head is pretty basic and simple. No sweat - take your time and concentrate - doing all those 18-bolts up will wear you out, so do the head and take a break before doing the rest.

Les.