Head Gasket Replacement

[frogeye]

Hi,

 

I am shortly to undertake a head gasket replacement on my T-reg 2.3l auto galaxy 99k miles. The symptoms are a massive pressurization of the coolant system, the thermostat housing has split, bottom radiator hose was blown off it's fitting. I've looked at the spark plugs and they are all dry.

 

Since the initial incident, which comprised an engine shutdown following a 5 mile journey with the bottom radiator being blown off, total loss of all coolant, I have refilled the coolant but whilst the engine turns over it doesn't fire. There is some beeping from the instrument panal (I must remember to nip out and count the beeps next time) and a petrol smell whilst trying.

 

Anyway I have resigned myself to undertake a head gasket replacement (with the assistance of a competent friend), and wonder if there are any other jobs / components that I should be replacing when doing this. I am currently intending the following:

 

Head gasket replacement

New thermostat

New thermostat housing

Replace water pump (have suspicion that this maybe the root cause of the gasket failure)

Replace aux belt

Oil filter

Oil change

Coolant fill

 

I was not intending on changing timing chain or tensioner, but would welcome any tips, warnings or whatever the forum cares to respond with.

 

Thanks in advance,

 

Frogeye

[sparky Paul]

Your list of replacements seems sensible to me, I can't think of anything else. As for the timing chain and tensioner, you can have a look at the condition of these when the head is off and make a decision. If you have had HGF, there is also the possibility of lambda sensor and/or cat damage, I had to replace both on the last head gasket I did, but you can cross that bridge if/when you come to it.

 

I'm a bit surprised you can't get the engine to fire, especially if the plugs are dry after attempting to start from cold. Even if the gasket has gone between cylinders, you usually see some sort of attempt to fire up... You are obviously getting fuel through, but is there any spark? I'm not sure about the beeping from the dash, but it must be trying to tell you something... someone else might be able to help you with this, but I suspect you might have to get to the bottom of it.

 

Have you done a cylinder compression test to confirm HGF? You don't mention of any sign of oil/water mixing, or fumes/bubbles in the header tank, that would be my starting point before whipping the head off. Also consider a cooling system pressure test with the plugs out.

 

Some other possible causes of over-pressure could be defective thermostat or pump, a blockage somewhere, or even frozen coolant, given the recent weather.

 

 

Good luck with it!

Edited January 23, 2010 by sparky Paul