e30 (325) BLEEDING COOLING SYSTEM... URGENT

[richeg33]

Hi there i have a 325 sitting on the drive which had a leaking rad... i have fitted a new 1 takes 10 mins but have been trying to bleed the cooling system all day with no success, the radiator isnt blocked and i have checked the thermostat with boiling water and thats fine but everytime it looks like all the bubbles are out of the bleed hole i open it 5 mins later to double check and all i get is steam please help i have bled hundreds of systems in my time and this is the only 1 that i havent sorted within half an hour... any help will be most appreciated thanks, rich

[maxfield]

M20's can be a bitch to bleed.

I driller a small (2mm) hole in my thermostat to help things.

Also jacking the car up so the expansion bottle is the highest point on the cooling system can help.

[richeg33]

thanks il try gettin the expansion tank at highest point in the system now i have already drilled a small hole at the top of the thermostat from previous advice i will let you no how i get on because this is becoming a right bitch lol thanks

[richeg33]

looked better than before while bleeding used hose (on slow) to keep pressure in expansion tank up and left bleed open for 5 minutes once coolant started coming through there was little or no bubbles what so ever with this method left running everything seems fine so open bleed again to make sure no more bubbles and all i get is steam? confused.com any ideas maxfield?

[sunnyr83]

Allow the bleedscrew mate, theres a better way, without drilling which involves running the car with the heating on full and leaving the water tank cap off. Do a search on this topic been covered a fair few times.

[kombikat]

I have always found that uncoupling the far end of highest hose on the thermostat housing, filling it with water and then recoupling it works

[richeg33]

tried everything now and still no joy over the past few days, my brothers a mechanic still no joy and just when you think its done its pisses out the water cap anyone local to slough who could help me ? many thanks

[richeg33]

bump

[richeg33]

could it be a water pump issue ???

[mrLEE30]

Does the radiator and hoses to/from the rad get hot?
Do you get hot air from the heater?
What does the temp guage do?

Either running it dry has killed your water pump(due to first leak) or worse you have damaged the head gasket.

[Hayden0]

I had the exact same problem as you the first time I did mine, the car was facing down hill the first time. The second time I had it on perfect level ground took the bleed screw right out and kept filling the expansion tank to the neck with water once it started flowing out the bleed screw I tightened it up then ran the engine and topped up with about 1/4 litre if that and it's been spot on since? No extra bleed been required. Hope you have success

[Tom_Maverick]

sounds like the headgasket.. if you take the lid off the expansion tank when the car is running is it bubbly? put your hand over the top and feel for pressure, (watch out as it'll be hot!) I did my waterpump a couple of weeks back and had none of these symptoms!

[Tay]

you need to do this from cold, the way that i've always bleed them is but getting a big funnel and pushing it into the tank and filling it up with the bleed screw out and keep pouring until the water jets out of the bleed hole then close the bleeder and put the cap back on, then run the car till hot checking the hoses and heater, once the heat is there turn it of alow to cool down to cold then check the water level, sometimes it helps to give the car a drive and the fluctuation of revs and movement often clears any airlocks!

[richeg33]

HI GUYS PANIC OVER thanks for all your help it boiled down to the new rad being crap it held water and pressure fine and it got to the stage where we couldnt think of anything else other than take the rad and put the old one back in with the leak, when we took the brand new one out my brother covered one pipe and blew into the other and the top left bleed pipe which leads back to the expasion bottle was blocked !!! so it was traping air it the system the whole time, luckily the engine seems ok. headache over thanks for all your help

[Tay]

glad to hear!!!!