[droverdave]

Afternoon all,

Talkin about a standard g13a

So my cooling system is being pressurised like crazy and im getting ovheating issues and i think losing coolant slowly.

When i say pressurised cooling system, im talking radiator hoses get twice as big due to pressure. its not normal coolant system pressure, and i can tell its air in there as its like a balloon.

It seems to be a gradual process, drives alright for ~30mins, but then it starts warming up.

My current theroy is i have a blown gasket between a cylinder and a water gallery, on the compression stroke it pumps air into the coolant system, and on the intake stroke it pulls in coolant and sends it out the exhaust.

Before i pull off the head tonight, is there any thing i could be missing to do with coolant bleeding of this engine that i am unaware of?

Perhaps maybe i have gotten an airpocket somewhere and that is what is pressurising my system. (and my loss of coolant is unexplained...)

My coolant bleeding is quite simple, fill it up, turn heater on full hot, start engine with cap off, let it heat up, keep adding water as needed, give the radiator hoses a few good squeezes to get any air out, maybe a few stabs of throttle to try burp out water, put cap on and happy motoring.

Theres nothing else for a G13a? (ive worked on cars with bleed screws, but nothing i can find talks about this)

And i have replaced everything that touches coolant in this engine in the last 2000kms (new radiator, water pump, radiator cap, thermostat, radiator hoses). and i have a normal fan and oem fan shroud.

I have also replaced the headgasket as well ~3000km ago, but yer, it appears to have blown again (poor quality aftermarket gasket is my theory here, as ive replaced many headgaskets, never had one fail so quick).

I had happy motoring for ~1500km after i did the head gasket last time, so this drama has developed recently....

ok go!

[atari4x4]

park the thing up hill, heater on & fashion up something like this with a 2l coke bottle to raise the highest point of the cooling system even higher, just needs to be a snug fit in the filler neck rather than butchering a radiator cap.



Mr Steak_Kinfe also suggests removing the bleed nipple jigglier thingo from the thermostat to assist in bleeding.

[charlie]

Is there coolant in the oil

[atari4x4]

+1 to that ^^^

did you get the head machined & the block checked for flatness?

[JrZook]

Did you re-torque the headgasket after you installed it and put it through a few heat cycles?

[droverdave]

hi all thanks for your replys.

charlie: nope. all good and proper.

atarai: yer i had the head reconditioned when i had it off, few new valves, valve stem seals, valve grind and a flatten (~$400)

jrzook: nope i didnt, the instructions on the gasket didnt say to do it, and i asked the machinist and he said it wasnt needed. im starting to think its a good idea.

Didnt get to it tonight (new shock absorbers in wifes car instead...). repco have a headgasket on the shelf, gonna pick it up tomorrow and then swap it over tomorrow.

so i filled up the water just before i left work today, drove around 20km home, reasonably traffic, but flowing.

got home to this..

I think im going to get a new radiator hose, these that i got from 4wd products are just too soft rubber.

[atari4x4]

mono-torque head gaskets bring the suck IMO

[JrZook]

droverdave wrote:

jrzook: nope i didnt, the instructions on the gasket didnt say to do it, and i asked the machinist and he said it wasnt needed. im starting to think its a good idea.

I have seen this many times on these G engines. I re-torque once its done a 100ks or so, no more issues. You would be surprised how loose those bolts can actually be after a few heat cycles!

[droverdave]

yer i think i will do it this time, serves as a good time to give the tappets another go as well at the same time.

What are your thoughts on the head bolts? should they be replaced?

I don't belive they are the "torque to yield" type.

[JrZook]

I've never replaced a set before (on 4 different engines)

[droverdave]

yer i even reused some torque to yield once went good for a few yrs, but the next owner blew the headgasket:P

[fordem]

If you can get a hose to swell like that without the radiator cap relieving the pressure, you either have a faulty cap (remove it and squeeze it between finger & thumb, you should be able to depress the spring) or the hoses are on their way out.

I'm not saying that you don't have a gasket problem, but rather, you may also have a hose problem.

[droverdave]

Yes i have been very skeptical of these hoses and cap.

I bought these, on a bit of a whim, as i needed some hoses cheap to get me on the road.

http://www.ebay.com.au/itm/Radiator-Hos ... 35ab56b8e9

They feel ok when cold, but hot, they feel very soft. i think ill pick up something else tomorrow, see what repco has to offer. the other two hoses do simliar, not as pronounced though.

unfortunately the OEM hoses were very cracked and i had to cut them off the radiator they had been there for that long, but i can tell they are much better quality rubber.

The cap is from those guys as well, but seems to be ok (can depress the spring). but ive not seen it release any pressure....(little bottle stays the same level always?)

I would have thought the cap should relieve as well. no idea what its rated to, but far out theres some pressure in that hose when it gets hot. like you cant squeeze it.

[droverdave]

ok so i have some results.

Whipped the head off on saturday, and first thing i noticed was that the head bolts did not seem to be that tight. Certainly wasnt the 70nm that i did them up to. so reckon this was the issue.

We actually considered just torquing them down without removing head, but figured i had a new gasket so best to just change it.

Pulled the headgasket off, and we couldnt find any major faults in it, we reckoned we could see a bit of black on the head itself where the gases were getting into the cooling system but nothing major. certainly no "blow out" of the gasket, so theory being the slightly loose bolts just letting some gases across the gasket.

So cleaned up the head and block with a razor blade, slapped new headgasket on, torqued it up and took it for a spin.

Also bought some gates radiator hoses which are much better than the garbage i got from that ebay link, and gates werent that much more cash either.

So i did about 70-80km on Saturday, no worries at all, no pressurising, held temperature very well (better than i have seen it ever to be honest, so perhaps its been leaking for a while).

Whipped the rocker cover off yesty morning and got the torque wrench onto them, found 2 of the bolts took a few degrees of rotation to get it up to torque, but most of them were fine.

Will give them another torque this weekend i think, just to make sure.

Ended up getting a headgasket at repco, "payen" brand i think, gasket didnt look the best...but only thing availble.

3hrs to change a headgasket at a cost of $22, not to bad we thought!

So if your going to change the gasket, it seems its definately worth while checking headbolt torque soon after you install.