E36 328 coolant woes AGAIN.....
Discussion
Right as per my previous post, before i changed the thermostat housing the car was using a small amount of water. Now its been changed out, its using a fair amount. Probably topping up once a week.
Car is running perfectly, no froth / discolouring or mayo and temp needle is Rock solid in the middle.
Last week i could hear hissing from the rad cap, so changed the rad cap and the bleed screw.
Over the weekend the coolant dropped again (with use) and yesterday i put probably 300ml in it to bring it back to normal. I didnt use the car yesterday, went to use it this morning and the coolant message is on the BC. Coolant level looked fine, no puddles under the car so i drove it work. Light goes off when your driving but second i stopped the light came back on. Level again looks ok, probably 3-4 inches from the top and 2" above the cold level.
I checked the bleed screw and only water coming out of there.
Not sure if it was water from the bleed that has spilled but it looked like the low level coolant switch was damp. (im guessing thats the one below the small pipe on the bottom of the header tank??)
The Thermostat housing seems to be sealed properly and no leaks from there or from the rad pipes that i removed to change it. Is it worth getting new rad hoses? i heard the top one is prone to breaking down.
Do i have 2 problems?? a leak and a switch and do you think they could be related? I.e. the switch breaking down. had it before on my golf where an oil pressure switch broke down and leaked everywhere.
Car is running perfectly, no froth / discolouring or mayo and temp needle is Rock solid in the middle.
Last week i could hear hissing from the rad cap, so changed the rad cap and the bleed screw.
Over the weekend the coolant dropped again (with use) and yesterday i put probably 300ml in it to bring it back to normal. I didnt use the car yesterday, went to use it this morning and the coolant message is on the BC. Coolant level looked fine, no puddles under the car so i drove it work. Light goes off when your driving but second i stopped the light came back on. Level again looks ok, probably 3-4 inches from the top and 2" above the cold level.
I checked the bleed screw and only water coming out of there.
Not sure if it was water from the bleed that has spilled but it looked like the low level coolant switch was damp. (im guessing thats the one below the small pipe on the bottom of the header tank??)
The Thermostat housing seems to be sealed properly and no leaks from there or from the rad pipes that i removed to change it. Is it worth getting new rad hoses? i heard the top one is prone to breaking down.
Do i have 2 problems?? a leak and a switch and do you think they could be related? I.e. the switch breaking down. had it before on my golf where an oil pressure switch broke down and leaked everywhere.
Mine was doing a very similar thing to what you describe.
It started out very small but over time it got worse, once it got worse however I could see where it was coming from.
It was coming from the bottom of the expansion tank which is removable from the radiator. The rubber seal must have broken down or something. A new seal and it stopped the leak. It was hard to find out where the leak was coming from as water finds its way everywhere.
It started out very small but over time it got worse, once it got worse however I could see where it was coming from.
It was coming from the bottom of the expansion tank which is removable from the radiator. The rubber seal must have broken down or something. A new seal and it stopped the leak. It was hard to find out where the leak was coming from as water finds its way everywhere.
i cleaned and dried it all off this morning, cant see any more water. Going to wait until it cools down to see if i've lost any water today.
Only thing i've been thinking is if my coolant message is saying low (after i've filled it back up like this morning), would this indicate that the leak is getting the connector for the low level sensor wet and shorting out the connections, giving me the erroneous messages.
Only other thing was that when i got home and turned the car off the rad cap was hissing like a good'un. I would imagine this is normal as the pressure has to drop off somewhere.
I'm sure its still not a major leak, but its very disconcerting when i planned a 120 trip this evening and the car was saying its low coolant message!
As far as bleeding, i probably didnt bleed it amazingly, i just topped it up, then the car overheated and i read how to do it properly. If i open the bleed screw i get pure water out now.
As for the components, i've only had the car 2 1/2 months and the only things i've replaced are the rap cap and bleed screw. (and the thermostat housing and thermostat)
Speaking of which, the new termostat was marginally higher temp than the old one. 95 as opposed to 92 i think. Car still runs perfect rock solid temp though, no overheating issues even on hot days in traffic.
Only thing i've been thinking is if my coolant message is saying low (after i've filled it back up like this morning), would this indicate that the leak is getting the connector for the low level sensor wet and shorting out the connections, giving me the erroneous messages.
Only other thing was that when i got home and turned the car off the rad cap was hissing like a good'un. I would imagine this is normal as the pressure has to drop off somewhere.
I'm sure its still not a major leak, but its very disconcerting when i planned a 120 trip this evening and the car was saying its low coolant message!
As far as bleeding, i probably didnt bleed it amazingly, i just topped it up, then the car overheated and i read how to do it properly. If i open the bleed screw i get pure water out now.
As for the components, i've only had the car 2 1/2 months and the only things i've replaced are the rap cap and bleed screw. (and the thermostat housing and thermostat)
Speaking of which, the new termostat was marginally higher temp than the old one. 95 as opposed to 92 i think. Car still runs perfect rock solid temp though, no overheating issues even on hot days in traffic.
Edited by S3_Graham on Tuesday 27th July 18:44
S3_Graham said:
Only other thing was that when i got home and turned the car off the rad cap was hissing like a good'un.
Sounds to me like you have the early signs of a leaky head gasket.Try this:
Before you start the car in the morning, open the rad cap to release any pressure.
Then, reseal the rad cap tightly, start the engine and run for 5 - 10 seconds and turn it off.
Release the rad cap, and listen for any (excessive) pressure release.
There may be a very feint 'psshhh' but that's all it should be - very, very slight.
If you have a pronounced 'psshh' then that suggests that the cooling system is being pressurised excessively from cold - which means that the head gasket is probably leaking...
I've had head gaskets go, with only the tiniest sign of oil in the coolant. So don't think that just because there is no mayo / sludge, that the HG is ok.
Edited by TonyRPH on Tuesday 27th July 22:05
drove the same route this morning to work, got there and popped the bonnet. Not a sausage from the rad cap. totally silent.
Thats the annoying thing, its so random! It seems to be fine, then one day it just drops! If i wasnt getting pure water from the bleed screw i'd think it was an air bubble trapped.
Thats the annoying thing, its so random! It seems to be fine, then one day it just drops! If i wasnt getting pure water from the bleed screw i'd think it was an air bubble trapped.
S3_Graham said:
drove the same route this morning to work, got there and popped the bonnet. Not a sausage from the rad cap. totally silent.
Thats the annoying thing, its so random! It seems to be fine, then one day it just drops! If i wasnt getting pure water from the bleed screw i'd think it was an air bubble trapped.
When Bleeding the system did you have the heater controls set to maximum? as an air lock willThats the annoying thing, its so random! It seems to be fine, then one day it just drops! If i wasnt getting pure water from the bleed screw i'd think it was an air bubble trapped.
live in a heater matrix if it's not set that way whilst you're bleeding it.
Edited by tdm34ds on Wednesday 28th July 10:58
Edited by tdm34ds on Wednesday 28th July 11:07
surely i need to get it hot to get some pressure into the system to force the air out though??
bearing in mind i have already re-filled the system, your saying that if i go to the car now (cold, ignition on, temp hot) and take off the bleed screw and pour some water into the header tank it should spill out of the bleed screw?
What difference does the hot on the temp thing make if the car isnt actually hot? is it to do with the position of valves or anything?
ETA: if i change to a lower thermostat would that theoretically drop the pressure and may cause the the leak to stop?? How do you get a lower thermostat? surely you just ask for the correct one and you should get it?
bearing in mind i have already re-filled the system, your saying that if i go to the car now (cold, ignition on, temp hot) and take off the bleed screw and pour some water into the header tank it should spill out of the bleed screw?
What difference does the hot on the temp thing make if the car isnt actually hot? is it to do with the position of valves or anything?
ETA: if i change to a lower thermostat would that theoretically drop the pressure and may cause the the leak to stop?? How do you get a lower thermostat? surely you just ask for the correct one and you should get it?
Edited by S3_Graham on Wednesday 28th July 14:45
S3_Graham said:
surely i need to get it hot to get some pressure into the system to force the air out though??
No, that's the job of the water pump. However, the thermostat does need to be open for best results (which means an engine at running temperature). As others have pointed out, the heater valves should also be open. If you have electronic climate control, simply turn it up to max. temperature - if you have dual climate, be sure to turn both up. Also be sure to turn the center vent to maximum heat as well.It's also a good idea to raise the front of the car. This is a well known tip for bleeding BMW's (E34/E36 +others).
Have you read my testing tip above? You seem to be floundering around, instead of paying attention to the advice offered here.
S3_Graham said:
ETA: if i change to a lower thermostat would that theoretically drop the pressure and may cause the the leak to stop?? How do you get a lower thermostat? surely you just ask for the correct one and you should get it?
No. The thermostat is there to regulate the engine temperature, it should have no effect on the system pressure (unless you change it for some radically different temperature).The cooling system is moderately pressurised to raise the boiling point of the water.
IIRC, this is controlled by the temperature and the bleed pressure of the radiator cap. But under normal operating conditions, no pressure should ever be bled off by the cap. The cap will usually bleed off excess pressure when the system boils - and when the system boils, that usually indicates some kind of fault....
Higher pressures raise the boiling point.
Lower pressures reduce it.
Anti freeze also raises the boiling point.
Edited by TonyRPH on Wednesday 28th July 15:42
TonyRPH said:
Have you read my testing tip above? You seem to be floundering around, instead of paying attention to the advice offered here.
I am listening and its appreciated, but while im at work i dont have a chance to try any of the things mentioned late last night or during the day.... ETA: Right,
Did you 5-10 sec running thing, not even a tiny hiss from the cap. I then ran the car for 15mins to get it to normal running temp with full hot selected on both controls. Centre wheel set to full hot with the blower on full blast. Got it hot then drove it up a slight slope and opened the bleed screw. Mostly water came out, no great hisses (however the car was running) but did seem to go in almost waves, like i open it and some comes out then the flow decreases then i open it a bit more and it surges out and then goes to more of a slower steady flow.
Now i've left it to cool down and i'll check the level and report back. Going home from work in an hour or so.
Edited by S3_Graham on Wednesday 28th July 18:17
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