Symptons on a blown head gasket...

[kam-325i]

What are the signs of a blown head gasket, as i am having problem with overheating STILL !!!!!

[smithy318i]

HUGE Plumes of steam from the exhaust
Yellow Cream on the inside of the oil filler cap

[herman]

Overheating and coffee coloured creamy gunge on oil cap, ok for a while then she blows and Ԛ£500

[kam-325i]

HUGE Plumes of steam from the exhaust
Yellow Cream on the inside of the oil filler cap

Thats just it, i dont have any of these symptons, no steam, no mayo, no loss of water. Its really doing my head in........

[panesar_e30]

could be a dodgy thermo.

[kam-325i]

could be a dodgy thermo.

I have tested it, i put the kettle on, boiled the water, put the thermo into a mug, and poured the just boiled water over the thermo, and it opened ok.

The water coming out of the rad is getting cooled, could it be that the thermo is just not opening up enough ?

[BrAdZ]

Try replacing the blue temp sender.

Have you replaced the viscus coupling? have you checked if its working?

How does it overheat?

[panesar_e30]

strange!

[kam-325i]

try the blue temp sender im guessing its a 6pot?

I thought the blue one was for the ECU. I know the brown one is for the temp gauge on the dash, as i disconeccted the wire and ground it, the temp gauge went to red.

Yes it is a 6 pot

[Dan318-is]

try running your car with the heating on an see if it overheats

mine only overheats if i leave heating off, so i therefor have to drive everywhere with it on

heater matrix pipes iv been told is the cause of this

have you checked your rad for cold spots?

[Ant]

Make sure the small bore hose from the rad to expansion tank is not blocked, this can and will cause blown headgasket symptons

pull the hose off both end and blow through it, obv should have no obstructions

If the H/G has failed, you car should be loosing coolant, if thats not the case then its a problem with circulation or pressurisation

keep us all posted dude

[kam-325i]

It gets hot wheter the heater in on full whack or not.

The small hose from the top of the rad to the expansion tank has been checked, no blockages there, but i did find a blockage in the small tube that connects to the hose that goes to the TB from just under the thermo housing, this has been cleared, but no difference.

The only indication i have that is is getting hot is the gauge, ill change the temp sensor (brown one) and see if that might be the problem. there is a vast difference in temp's between the water entering the rad and it leaving, the top hose is hot, cant hold hand on it for very long, bottom hose out of rad is a hell of a lot cooler.

The only other thing i can think off is a shagged water pump.

[JOSEMI]

I would say maybe air in the cooling system and stopping the water from flowing freely in the system

[kam-325i]

I would say maybe air in the cooling system and stopping the water from flowing freely in the system

I have bled the system loads of times with no differance.

[JOSEMI]

It used to happen to me as well, its quite disturbing as nothing 'seems' to be wrong apart from the fact that your car decides just to overheat and give you a bad time.
There are some clues above on how to sort it: check the heater matrix behind the middle console for signs of leaks, obviously you have bled the system a few times so discard this for now (until the system works ok), and the thermostat. Patience, loads of water in the boot just in case and lots of time with the heater on even on a sunny day help relieve the overheating, and check that the needle does not get near the read zone of the 'thermometer'.
For what I read it seems like your car is not operating the cooling system in time or properly and this is causing you problems ?

[koos]

Take a hose off and run the engine, if water doesnt pump out then the water pump is poked like you say. Check that the thermostat is in the right way round(not sure on beemers if it can be put in wrong). If both are okay then the rad might be blocked(unlikely), take both the top and bottom hose off and stick a hose pipe in the top and check if anything comes out.

Lastly check that the rad is not blocked in front, grass etc. If you still think its the gasket, check if its pushing compression into the expansion tank.
HTH

[kam-325i]

If you still think its the gasket, check if its pushing compression into the expansion tank.
HTH

If it is pushing compression into the cooloing system, would'nt that result in water loss, thru the system being over pressurised and water being expelled thru the expansion tank overflow ?

[koos]

sometimes it only push's small bubbles into the cooling system, just check it with the cap off.

[kam-325i]

sometimes it only push's small bubbles into the cooling system, just check it with the cap off.

What should i be looking for ?

[koos]

When its idling, take the cap off the expansion tank and check if there are bubbles coming up trough the coolant, if so then the gasket is gone. You can buy a tool from most tool places that you stick over the filler of the tank and if there is compression in the system it changes the colour of the liquid in the tool.
HTH

[kam-325i]

I know what you mean, i was at MoseleyMotorsport and saw Nigel using somthing like a big syringe on the expansion tank tank on a M5 looking for a duff head gasket, i think i will ask him nicely if he can quickly test mine......

[MikeF]

Hi, Just reading your problem with your car overheating I once had the same symtoms on my 325i for days and i found it to be an airlock in the heater matrix. I undid the top hose to the heater (Bulkhead) with a running hose pipe (from the tap) into the expansion tank and blew a huge amount of air out and then water came through. I know you might of already tried it or I'm not trying to teach you to suck eggs but its a suggestion!!
Mike.

[kam-325i]

Hi, Just reading your problem with your car overheating I once had the same symtoms on my 325i for days and i found it to be an airlock in the heater matrix. I undid the top hose to the heater (Bulkhead) with a running hose pipe (from the tap) into the expansion tank and blew a huge amount of air out and then water came through. I know you might of already tried it or I'm not trying to teach you to suck eggs but its a suggestion!!
Mike.

Sounds like a good idea to me, i will try it, as it was the hose from the engine block to the heater that went last..........

[Brianmoooore]

My experience of airlocks in the heater pipe is that the temp gauge goes off the clock within a few minutes of starting the engine. Very common to have airlocks here if the block has been partially or fully drained.
Another check for a blown headgasket pressurising the cooling system is to put a exhaust gas tester probe into the air at the top of the coolant tank. If the gasket is gone, then it will detect exhaust gasses.

[TOURINGDADDY]

from what ur saying ur going by the temp gauge but does it wet it self when it gets hot or does the gauge just go up if this is the case the try doing the nut up on the back of the clocks. could b that simple

[kam-325i]

I undid the top hose to the heater (Bulkhead) with a running hose pipe (from the tap) into the expansion tank and blew a huge amount of air out and then water came through. Mike.

Well i gave it go last night, took of top heater hose, clamped, a started to pump water thru system for a good 20 mins, the where a load of air bubbles coming out of it for the first 5-10 mins.

Buts it looks like to cured my porblem !!!!!!!! normaly on the way to work, the temp gauge makes it way up to 3/4, as there is a nice long uphill section, and this normally gets the temps rising, but this morning, it hardly made it to 1/2, and that is stuck behind a tractor for 6 miles !!!

[oze30]

So if you have white smoke, but no mayo.. but the smoke is intermittent, WTF does that mean??? I don't think there's coolant loss, but will top up and check when the sun's out ( or rather hiding) Not looking forward to replacing the head gasket as i just bought the tourer for Ԛ£500! Insurance Ԛ£500 and tax Ԛ£97 for 6mths.

As we aussies say.. Buggar!

[m-dtech]

im thinking possibly a waterpump problem ???

[oze30]

could you explain further? Is that hard to replace?

[m-dtech]

not really that difficult, the fans on the water pump could be fecked and its not flowing fast enough at idle.

think they are bout Ԛ£30

and you can do your belts at the same time

[oze30]

it happens under throttle too. Im still confused how a busted waterpump would give off white smoke?

[oze30]

DOH!

Just realised you were talking about the overheating!!!