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over pressurising cooling system causing over heaten........

Posted: Sat Sep 04, 2004 6:45 pm
by MUSS
ok i still have the problem of my overflow bottle overflowin and loosen alot of coolent have been to my mechanic and he did a CO2 test for emissions causing pressure build up in the coolin system...and the test came back negativer so no cracked head or leekin head gasket.....have changed the coolant recovery cap a number of times now (3 :roll: ) so i changed it again... and yesterday i noticed the little spring on the front of my viscus fan had been broken for a while so i bought another viscus hub and topped it up with oil and put it on..have noticed im gettin alot better air flow now then i was gettin before but that is bout all :cry: ...what i dont understand is that the thermostat is workin great.... but i the cooling sytem is still gettin overpressurised ...the only thing i can do is one of two things...one replace the thermostat or two...remove it all together and see what happens...... please let me know what ya recon cos i dont have to many more ideas :? :?

Posted: Sat Sep 04, 2004 6:57 pm
by Shadow
you could have really bad airlocks in the system

since air expands much more per volume than water, the system will reach nominal pressure but displace way more water...

you could try removing a heater hose from the highest point on the engine, and keep filling the radiator etc up.

i havent heard of the 3B getting major airlocks, but since i got a new radiator on my 2H it is MUCH harder to fill the system, and if i completely drain the system i now must remove a heater hose to get rid of airlocks.

You could also have a leak in your turbo (if the turbo is coiled by water and oil), maybe high pressure from turbo is getting past a seal which wouldnt normally leak and into the coolant some how...

Posted: Sat Sep 04, 2004 7:39 pm
by MUSS
Shadow wrote:you could have really bad airlocks in the system

since air expands much more per volume than water, the system will reach nominal pressure but displace way more water...

you could try removing a heater hose from the highest point on the engine, and keep filling the radiator etc up.

i havent heard of the 3B getting major airlocks, but since i got a new radiator on my 2H it is MUCH harder to fill the system, and if i completely drain the system i now must remove a heater hose to get rid of airlocks.

You could also have a leak in your turbo (if the turbo is coiled by water and oil), maybe high pressure from turbo is getting past a seal which wouldnt normally leak and into the coolant some how...


the turbo is only oile cooled and have no oil contamination in the coolant at all i will try and get rid of the air lock by removen a heater hose see what happens... i have filled the raidiator back up before by just it filler neck om the motor and had no problems but i am keen to try and look at any possibilities thanks shadow :cool:

Posted: Sat Sep 04, 2004 8:02 pm
by dumbdunce
yeah give the air lock theory a try, I had bad air lock problems with the bundera and when I got all the air out of the system it worked a lot better - never great and it always ended up pressurising again sooner or later.

you CAN NOT run a 3B without a thermostat, the thermostat is a bypass type and without it some of the coolant will continue to bypass the radiator and may end up with some overheating.


did you get your air compressor sorted out?

cheers

Brian

Posted: Sat Sep 04, 2004 8:08 pm
by MUSS
dumbdunce wrote:yeah give the air lock theory a try, I had bad air lock problems with the bundera and when I got all the air out of the system it worked a lot better - never great and it always ended up pressurising again sooner or later.

you CAN NOT run a 3B without a thermostat, the thermostat is a bypass type and without it some of the coolant will continue to bypass the radiator and may end up with some overheating.


did you get your air compressor sorted out?

cheers

Brian


hmmmm what bout runnin a custom set up water pump to get better flo?

not yet gotta find the time :cry:

Posted: Sun Sep 05, 2004 10:28 am
by madnavi
Muss

I have ran my 3B without a thermostat and it ran fine not that this is the way to go.

I have also had trouble with an airlock but it was pretty big so it started over heating just with normal suburban driving so I dont know if this would be ykour problem

Posted: Sun Sep 05, 2004 11:24 am
by MUSS
madnavi wrote:Muss

I have ran my 3B without a thermostat and it ran fine not that this is the way to go.

I have also had trouble with an airlock but it was pretty big so it started over heating just with normal suburban driving so I dont know if this would be your problem


hmmm narh its just slowly fills the the overflow bottle sometmies even the next day the heater hose is still tight from the pressure in the system other days its just normal.........

Posted: Sun Sep 05, 2004 8:53 pm
by quick60
might be a dumb question, but did you run the engine with the heater on full to purge out the air from there ??

Posted: Sun Sep 05, 2004 9:34 pm
by MUSS
yeah actually i did run the heater to use it as a secondary raidiator...didnt realise it wood purge out the air tho....so if i had run the heater for a while like 3 hours..i shoodnt have air in the system? :?

Posted: Sun Sep 05, 2004 10:32 pm
by Shadow
MUSS wrote:yeah actually i did run the heater to use it as a secondary raidiator...didnt realise it wood purge out the air tho....so if i had run the heater for a while like 3 hours..i shoodnt have air in the system? :?


it will purge the air from the heater core

essentially pushing the air from your heater to the rest of the system and hopewfully out through the overflow.

Posted: Wed Sep 08, 2004 8:42 pm
by MUSS
OK replaced the thermostat and tested the old one....it was jammed and farked so hopin that was the problem :D thanks for everybodys input and help :armsup:

Posted: Sat Sep 11, 2004 6:01 pm
by MUSS
ok thort i had fixed the bloody problem... but funny that its still doin it andi got no farkin idea wtf is goin on....................hmmmmm stumped good and proper :twisted: :twisted:

water??

Posted: Wed Sep 21, 2005 4:53 pm
by toy73
i got a 3b. had a cracked head & it threw water every were if i ran it with no radiator cap. now it seems to never be full, i have to add about 300ml every time i take off the rad cap. I dare not touch the rad cap when its hot as it is under heaps of pressure. Is your rad cap on the thermostat housing?

Posted: Wed Sep 21, 2005 9:06 pm
by plowy
snap on sell a cooling system filler that stops you from getting airlocks ,
as it sucks the air out of the cooling system and then you fill the system all with one tool
it maybe a long shot but find a mech who's got one or even a rad shop and get them to give it ago on your rig , then you can rule out the air lock problem

Posted: Wed Sep 21, 2005 9:21 pm
by plowy
snap on sell a cooling system filler that stops you from getting airlocks ,
as it sucks the air out of the cooling system and then you fill the system all with one tool
it maybe a long shot but find a mech who's got one or even a rad shop and get them to give it ago on your rig , then you can rule out the air lock problem

Posted: Wed Sep 21, 2005 10:04 pm
by patrol man
to be the bearer of bad news, it will be a head gasket or cracked head for sure. there not that hard to do,.hears a diagnoses tip, get it hot, remove the glow plugs, fit a compression tester tool in this hole with air compressed air hooked up, (first setting the cylinder on dtc) with radiator cap remove, and oil cap, watch the radiator bubble,or over flow,then move to the next cylinder. ps don't stand to close, as a bad leak with blow hot coolant everywhere. this is a good way to check the ring as well,as it will leak past these to.

Posted: Thu Sep 22, 2005 8:47 am
by carts
I have similar issues with my 2h, although mine doesnt happen all the time. The car never over heats, although, when i am working it hard, it blows excessive coolant out the over flow.

I have gone through the same motions as you....replaced and cleaned everything. I have come to the conclusion that when i am working it hard, the waterflow through the head is not sufficient enough to stop instantaneous spot boiling in the head. Over all, coolant temps are ok, but hot spots cause pockets of boiling water, hence water being forced out the over flow. I only get this problem working the engine hard on stockton beach, or a good hard freeway run. Other than that, i dont use a drop of coolant and the levels always remain the same. I am running aftermarket turbo and a fair bit of boost for a 2h, so its no surprise that i am pushing it past the old 2h's cooling efficiency.

I suppose you could try a cooling system flush just incase there is crap blocking the water channels in your head, leading to poor water circulation. Other than that, i suppose you could install a higher venting pressure radiator cap. Increasing the relief pressure in the cooling system will raise the boiling point of the liquid in the system, thus reducing the likely hood of getting spot boiling.

Perhaps you are running to higher boost levels and overfuelling?

Posted: Thu Sep 22, 2005 10:27 am
by bj42turbo
MUSS wrote:OK replaced the thermostat and tested the old one....it was jammed and farked so hopin that was the problem :D thanks for everybodys input and help :armsup:
Hmm this thread has me thinking as my 3b seems to be running a bit hot at the moment (although not sure how acurate) the gauge is) Muss the thermostat you bought is it genuine or something else and are they expensive.


BJ


p.s I am thinking of buying an aftermarket Guage a good brand not the super cheap one bought a few weeks ago what temp should it be running on.