New cyl head fitted but

[splasher]

I have just fitted a new head to my 2.4 efi and while I was cranking the engine over to bleed diesel through I noticed the top hose was getting hard. I removed the pressure cap and it had pressurised the system. Is this normal or have I a cracked block? although I think if it had a crack I would of seen it when I cleaned it to fit the new gasket. Any Ideas welcome.

[Bogus]

Could be the system is full of air. Crank it with the rad cap off, if it runs, run it with the cap off for a while, you have to get all the air out of the system. Set all heaters to hot as well so that your circulating the whole system. Even after it warms up and stat is open, keep stopping it, and topping up the rad as required till youe sure all the air is out.

I,ll assume that the head torqueing was done correctly, that new TTY ( stretch) bolts were used for putting the head back. It is most likely to be air and you have to get it all out.

Did you also check that the block was flat/level ?

Bogus

[coolsv650]

I have just fitted a new head to my 2.4 efi and while I was cranking the engine over to bleed diesel through I noticed the top hose was getting hard. I removed the pressure cap and it had pressurised the system. Is this normal or have I a cracked block? although I think if it had a crack I would of seen it when I cleaned it to fit the new gasket. Any Ideas welcome.

You would not always see a crack in the block, that said the blocks seem pritty bullet proof (excuse the spelling fingers do not seem to be working properly).

Another method of bleeding the system is to fill the system then leave it with the rad cap off overnight, it works better if the front of the engine is higher than the back, the air then bleeds out to the highest point and you can just top it up again.

You might need to slacken the injector pipes to get it to bleed if it is being difficult. I have ended up doing that in the past. (slacken them, turn over the engine until fuel starts to spurt out then tighten them)

[splasher]

Thanks for all your ideas. I have got her going now but she heats up very quickly, so I removed the thermostat. I still have the problem of keeping coolant in her (with or without the stat). Starting her up from cold she gets rid of a litre of water in less than a minute. I have removed the radiator and back flushed it and flushed the heater and pipe work. I will try raising the front and leaving her over night with cap off but before I do I will drain the system so I can measure the amount of water I put in. Does any one know what the coolant capacity is. Cheers

[sledge]

here this should help

http://www.toyotasurf.asn.au/techsite/24lt.htm

[splasher]

Thanks for the quick reply Sledge. 9 ltres then, I' give it ago tomorrow. Cheers

[splasher]

Progress report, well drained her down blew heaters out with compressed air. Filled it with just over 8ltres of water. Still the top hose went hard in no time. I Made up an adaptor out of an old glow plug and and schnider valve and replaced the glow plugs with it one at a time and posistioning each piston on tdc as I went. I Blew the combustion champers up with compressed air (100 psi)and found 1 and 2 cylinders were pressurising the cooling system. I will now have to remove the head to see what is going on. I will let you know what I find. Cheers

[WARRIOR72]

if its 1&2 pressurising the system i'd suspect either a warped or cracked block (fairly uncommon) or something wrong with the gasket/head or torque procedures? i was lucky? when my head cracked( ) i could plainly see no.4 had cracked between the valves and across the injector base through to the water jacket,so much so that it fell out when the head was removed!!
where did you get the head / gasket from and what procedure did you use for torquing the head down? new bolts used? did you make sure no water/oil etc was down the head bolt holes because if it was it would lead to a false torque/angle setting due to hydraulic action? good luck!!

[splasher]

Well I removed the new head today and found that the gasket has evidence of blowing between cylinders and into the water ways. I have checked and double checked for cracks in the head and block and found none. On checking the bolts I found that they are too long and bottom in the threaded holes before the head is fully tight. Although they are the same length as the old bolts. I feel that if I fitted a washer of 3mm thickness under the heads of the torx bolts it would cure the problem. I shall get a new head gasket tomorrow and a new set of bolts and try again. Oh Warrior head bolts and gasket from ebay and followed manual to the letter. I am not sure about you being lucky though!

[splasher]

And finaly fitted another new Head gasket today and new bolts munufactured by Payen. Torqued them down to 58 ft lb then 90 deg then on doing another 90 BANG went the first one pulled the thread right out of the block. So I set the torque wrench to 95 ft lb and tightened the rest, which was equal to 45 deg or 1/8 of a turn. (I put washers on the bolts this time to make sure the gasket was compressed). Anyway so far so good NO MORE PRESSURE build up in the cooling system and no more over heating. I just have to figure out a crafty way to repair stripped thread in block.
On conclusion I reckon the majority of head problems are the bolts stretching and then bottoming in the block before the gasket is compessed properly. The head cracking is most likely caused by the above because over time it blows your water out. Whats your view?

[drunkmonkeyboy]

interesting theory, if its true then by including changing these bolts with your regular services could reduce the change of the nasty happening. so who will dash our hopes that this could help???

[Vagrant No2]

On nearly all heads and head gaskets I have replaced over the years , I have always checked thread depths and bolt lengths before fitting the head . I also make sure no excess of oil/dirt is in thread hole as oil can cause a hydaulic lock and also shear the bolts as bolt is tightened down, aswell as letting oil onto face of the gasket as it seeks out the thread hole .

[Antshiel]

My mechanic said exactly the same about cheap stertch bolts bottoming out before fully torqued up. (he's a Surf owner too) and when replacing his head ground 1mm off each bolt. He also told me that under no cicumstances would this technique be used on customers cars as the correct bolts (dealer) should always be used. He just happened to have some spurious ones lying around so used them on his surf.

[WARRIOR72]

were the payen head bolts the same length as your other new ones? im not a big lover of putting washers under head bolts unless there meant to be there cos again this can lead to the washers squashing and giving another false torque reading.i nearly had two hernias tightening mine up on the second 90degrees!! i dont know what to suggest on the stripped thread on the block unless you can get a tap in there somehow or get it helicoiled if possible,but id sort it soon as as it would be the weakest link in your armour so to say!! them heads sure are heavy lifting them on your own onto the block so not to damage the new gasket lol good luck mate