Fixing P-Gasket leads to bigger drama's?

[ShaunDefender]

Hi Guys,

Im new to both the forum and Land Rovers,

My Defender 300Tdi has been leaking coolant for some time from the P-gasket area,

So yesterday I gave it some love, P-gasket, Water Pump, new header tank, full set of hoses, drive belts and tensioner and flushed the radiator.

Drove it last night to check for leaks all good. Drove it to work this morning and from job to job maybe 50 km's high and low speed driving all good.

Tonight driving home powering along at 100 the temp gauge went from normal straight to the red, I pulled up, coolant level all good, no leaks anywhere but a lot of pressure in the header tank.

After ringing my wife and asking her to bring the snatch strap, got it home did a few checks thermostat ok, water pump pushing coolant, viscous coupling all good, however did notice air pockets/bubbling into header tank.

Further to this removed bung from radiator and its bubbling also,

To me this seems like a Head gasket/head problem, could it have been possible that the head gasket has been leaking all along but the leaking P-gasket was allowing the pressure to release?

Any thoughts on this would be great?


On a positive note, with every little problem the defender presents, I get to know it a little better?????

Thanks

[camel_landy]

You may well be correct but do a couple of other basic checks first:

* Properly bleed the system and make sure you're not just shifting air pockets around.
* Get an external (laser) thermometer to just make sure the temp gauge is correct.

Assuming they're all good, looks like your 'P' gasket might have been a sympton of HG failure. FWIW - A HG change is actually fairly simple on the TDi.

M

[Toxic_Avenger]

Erratic high temp symptoms can be a sign of a poorly bled cooling system.
Not sure about your motor, but it helps to 'burp' it by filling the system the getting the thermostat to open followed by getting the bleed point higher than the cooling galleries in the head.

You can get Head gasket testing kits which can analyze the bubbles in your coolant for traces of exhaust gas.
Hopefully it just wasn't bled properly.

[ShaunDefender]

Thanks Guys,

As far as testing the temp gauge, she was definitely hot,

I will try to re-bleed the cooling system and see what happens,

Is it best to bleed at the top of the heater hoses?

Thanks

[Blknight.aus]

make sure your purge valve is operating correctly and try the coke bottle method first.

http://www.aulro.com/afvb/projects-tutorials/126121-coke-bottle-cooling-system-fill.html

[bee utey]

As Dave says, make sure the bleed hose to the plastic tee piece thingy is flowing freely. There's a restrictor jet in the branch from the top of the thermostat housing that is well known to block up. It acts as a jet pump to remove bubbles from the top of the radiator and carrying then to the header tank. Half the ones I meet have blocked up. When working they get rid of the need to do fancy bleeding as they self bleed quite happily.

[PAT303]

Just get rid of it and fit a simple T piece,I did that years ago and no issue bleeding it since. Pat

[lardy]

Sounds like air in the system possibly, did you allow the air out by running the engine whilst adding the rest of the coolant?

[Blknight.aus]

Just get rid of it and fit a simple T piece,I did that years ago and no issue bleeding it since. Pat

make sure you install the T piece the right way, it will cause issues if you put it in with the single leg pointing to the thermostat housing. Ideally if you can get one you want the type that is a straight through with a piece drilled and tapped to the center. These seem to encourage the radiator drawing process the most.

The best thing I've ever seen done was someone a lot more paranoid than me fitted 2 check valves before the t piece so that nothing could flow back into the radiator or the thermostat housing.

[ShaunDefender]

Hi Guys

I Tried, and tried again to bleed the system including using the coke bottle method,

In the end frustration and the need for the vehicle to up and going and reliable, I pulled the head to find the gasket showing some signs of leakage.

I couldn't find any cracks in the head itself, but with no means of having it tested with-in a 250km radius of where I am Ive ordered a new "Performance" head from turners along with bolts and gaskets.

It was the best way for me to know that everything thing was as it should be.

Also, when doing the P-Gasket i replaced the bleed hose set with a new genuine item that only appeared to fit one way, it did check it by blowing through and air flows freely from both the thermostat end and the radiator end through to the expansion tank, Is this as it should be?

Thanks for all the advice

[Jode]

Also, when doing the P-Gasket i replaced the bleed hose set with a new genuine item that only appeared to fit one way, it did check it by blowing through and air flows freely from both the thermostat end and the radiator end through to the expansion tank, Is this as it should be?

Thanks for all the advice
It should fit only one way, as the hose from the thermostat housing has a big kink in it that the other two which run from the valve affair to the rad top / expansion tank don't.