Radiator top hose hard even when engine is cold

[Great_White_316]

Hi shifus...I badly need some help here...i own a e46 325ci year 2001... 6months back i had an issue when every month i get the coolant light appearing every once a month and I will have to top up atleast a 1 litre of water in it....so to get it fix my i brought it to my mechanic and he said there is small leak on the radiator and your can weld it or change the radiator...so i decided to get a brand new radiator Behr brand and installed it as I didn;t want to mess around with the cooling system...

2 weeks later, again I have the coolant light appearing and when I pop my hood I see coolant stain around my radiator cap...so i believe there is still water coming off the radiator...I decided to change the radiator cap coz it was a little worn out...after changing it the same day the coolant light appeared...I brought it back to mechanic and ask him wtf again the prob is there....he does presure test and he says there is hairline crack on the expansion tank...changed to brand new original one for 300 bucks and drove back thinking the problem is solved.

But now...here's the current problem...after the changing the expansion tank I left the car untouched for 2 days...and the 3rd day i decided to check if the water level has gone down and the prob is solved.....without starting the car i popped the hood and open the cap...then cap just flew off with big sum of water shooting out like fountain....thank god the engine was cold and the water was cold as well....first time this has happen to me....

i take it back to the mechanic...he is 30 years experience working with AB bmw specialist(Yau in Jalan Ipoh)...the 50 year old man says i ithcy finger wanna go open the radiator cap when there was no any error light or no need to open the cap...then he did the bleeding for me and said u dont have to open the cap unless your car over heat or coolant light comes out...noisy old man thats very normal with him.....

Im driving the car for a week and the car runs perfectly fine...but when i try to squeeze the top radiotor hose in the morning its hard life a rock...so i believe there is still presure stuck in there....

what could be the issue shifus??? im praying hard its not a gasket issue....i have check for oil stain mix with the coolant or wat...the water seems to be clear....engine runs perfectly fine...temperature is normal...can someone recommend me to a bmw radiator specialist who can do the compression test or sniffing test???i realy need some reliable ppl ....please help....

 

[tweiboon]

Your thermostat still ok ? Cooling system only has water pump, tbermostat, radiator and expansion tank. Since you changed radiator and expansion tank so is only need to check thermostat. If water pump is out your car is on towing already.

 

[Vincent Hor]

Don't think it could be a thermostat problem but no harm replacing it if you haven't had it replaced. However I am of the opinion that you have an early head gasket problem. Excessive pressure at expansion tank when engine is cold usually points to a bad head gasket.

 

[Great_White_316]

Hi Vincent and tweiboon....hmmmm...havent checked the t-stat yet...but i changed it 2 years back....car still runs fine....tommorow im taking it to another bmw workshop in batu caves...hopefully they find the actual problem....if gasket gone any rough estimation for the cost of the bomb???any recommendation where i can find a good mechanic for a reasonable price to find the actual prob and get my car back to how it was...

 

[crusher]

I learnt something from this thread. Never open radiator cap unless you have reason to

 

[jarance]

The cooling system should not be pressurised when the engine is cold.

It will be pressurised when the engine is HOT.

The only possible reason for the pressure to built up is there is leak from the combustion camber to leak into the coolant chamber.

As mentioned earlier, it could be due to head gasket failure or crack engine head or crack water channel.

Most likely the cause is head gasket failure as there is no sign of oil in the radiator.

This problem arises due to previous overheating and cold water is added to the radiator before the engine cooled down causing the cylinder head to warp.

Open the radiator cap and try to smell for unusual odor.

 

[Great_White_316]

Jarance - any recommended workshop where worth giving it a try to confirm the issue???

 

[jarance]

I dont usually recommend any workshop.

but here are a list of workshops used by other people. Try below.

http://www.bmwclubmalaysia.com/newforums/index.php?/topic/237-list-of-good-workshops/

http://www.bmwclubmalaysia.com/newforums/index.php?/topic/5175-list-of-recomended-workshops/

 

[jarance]

Try reading this.

Extract from below link
Lastly, during the combustion process the high pressures in the cylinder can push exhaust gases past the head gasket into the engine cooling system. The exhaust gases will be trapped in the cooling system and will be circulated through your engine and into the radiator. During normal operation your engine’s cooling system remains under pressure, so never remove the radiator cap while the engine is operating or still warm. If your vehicle has a coolant overflow tank you can check that for the presence of bubbles. To be certain you can purchase a test kit from your local auto parts store that will chemically check your engine coolant for the presence of exhaust gases.



http://www.gobluedevil.com/blog/what-are-the-symptoms-of-a-blown-head-gasket/