Overheating 318is - Please help ??

Fri Nov 03, 2006 9:02 am

My 318is is overheating when stuck in traffic, the needle goes right up in
the red and I have to pull over to let it cool down. The car has had a new radiator so I dont think it is this - I have also noticed that the heating inside the car does not get hot at all (which is a pain now its getting cold) -
Im guessing these are linked, but as I have all the mechanical knowledge of a dead cat im not sure.

Just need a few Ideas to tell to the old man so he can take a look around.

PLEASE HELP !!!!!

Tom

Fri Nov 03, 2006 9:09 am

hi tom

had the same problem with mine a month back. ended up buyin and fittin a new radiator. it is a new radiator that you bought and not a second hand one is it? also see if you can take ur cra down to a garage and get the radiator pressure tested. also check all ur pipes and like usual check u got a good mix of antifreeze in there. dunno wot else could possibly work but i done all of those with mine and its no longer overheatin in traffic (touchwood!)

Fri Nov 03, 2006 9:19 am

If you've fitted a new rad, then it's (hopefully) not that.

Sounds like the thermostat has packed up. While you're doing that you might as well replace the waterpump too. If you have the rad out, it makes things easier to get to when doing this... I had to do this one mine as I had the same symptoms.

Fri Nov 03, 2006 9:28 am

A couple of things that might help..

1: Remove thermostat completly and see if this helps.
2: If rad replaced recently, make sure you haven't got an air lock.
3: Make sure your coolant level doesn't drop over night (might have a leak)
4: Is rad fan working ok?
5: Agree with Geeman, might as well replace water pump to be on the safe side as overheating can cause all kinds of problems..!!

Fri Nov 03, 2006 9:32 am

Stealth wrote:2: If rad replaced recently, make sure you haven't got an air lock.

That was my first thought.

Fri Nov 03, 2006 9:33 am

I had a coolant change in my E46 and an air lock developed about a week later.. need to make sure the system is fully bled, this is the first check as it's the cheapest...

Fri Nov 03, 2006 9:34 am

Thanks for your advice, I will ask the old man to check these things.

Would an airlock mean no heat in the cabin ?

Fri Nov 03, 2006 9:37 am

Yep, as the water needs to flow through the heater matrix, if it's locked somewhere, it won't produce heat..

Fri Nov 03, 2006 9:39 am

Cheers for your help - much appreciated

Fri Nov 03, 2006 9:41 am

Welcome, this is what the Zone is for..!!! here to help each other out

Fri Nov 03, 2006 10:57 am

1: Remove thermostat completly and see if this helps.
2: If rad replaced recently, make sure you haven't got an air lock.

My immediate thoughts too..

Fri Nov 03, 2006 11:10 am

Cheers Pal318is - two of us in Bedford then - Like those rims mate

Fri Nov 03, 2006 2:34 pm

I had the same on my is. The rad was removed to do some engine work, and I noticed after that the car didnt get warm inside, and then boiled over in traffic. (Whilst the engine work was being done a new thermostat and water pump was fitted.)

I had a major air lock that took ages to bleed out. With the engine running, put the heater on full on hot, and give the water pipes a good squeezing. Also use the bleed screw on top of the rad.

Mine after about 15 mins it made an almighty 'burp'

, and empitied the rad into the system

.

Just keep bleeding and squeezing till it wont take any more water.

The air lock on yours will most probably be in the heater matrix in the car. As soon as mine 'burped' instant warm air in the car, and no more overheating!

Fri Nov 03, 2006 3:06 pm

Just got off the phone to my dad - he has bled the radiator and tested the car - heat in the cabin and no overheating from the engine

Touch wood no more problems

Thanks to everyone for their help on this one

Fri Nov 03, 2006 3:31 pm

Good to hear you got it working with out having to spend any cash..!!! and at least you hopefully won't do any more damage..!!

Fri Dec 29, 2006 11:49 pm

Hi all, just to tag onto this post, I have just fitted a replacement m40 engine in my e30 318i. The temperature gauge now isn't working (tacho died so perhaps the gauge itself is just on it's way out) so that doesn't help, but I think there is something perhaps wrong with my cooling system.

After a reasonable idle/journey period, the top hose of the rad gets hot, and the rad right next to it gets hot. The heater blows hot no problems, but the bottom hose of the rad still feels cold, as does the rad itself.

Since I don't have a temperature gauge now, to tell me otherwise, would it be possible that the thermostat is dead? This engine is of reasonably unknown condition so could I just remove the thermostat all together? This would surely prevent coolant flow through the radiator from passenger to drivers side, which would explain cold rad and bottom hose? Or is it just me being paranoid and actually all is fine?

Please reply ASAP as I want it sorted tonight really!! Thanks

Sat Dec 30, 2006 12:07 am

MJG sounds like you need a new water pump.

Sat Dec 30, 2006 12:09 am

But the heater blows hot, and it squirts water out? How can I test this?

Sat Dec 30, 2006 8:06 pm

I had the same kinda thing with my E46, all hot apart from the bottom hose, ended up being the thermostat, it also caused it to be a right pain to bleed any air out of, so changed thermostat and away we go..

So try a new or even take out the thermostat and see what happens...

hope this helps..

Sat Dec 30, 2006 8:26 pm

tommoh3000 wrote:My 318is is overheating when stuck in traffic, the needle goes right up in
the red and I have to pull over to let it cool down. The car has had a new radiator so I dont think it is this - I have also noticed that the heating inside the car does not get hot at all (which is a pain now its getting cold) -
Im guessing these are linked, but as I have all the mechanical knowledge of a dead cat im not sure.

Just need a few Ideas to tell to the old man so he can take a look around.

PLEASE HELP !!!!!

Tom

Missed this one this morning somehow!
Definitely an airlock at the rear of the head. Driving a car in this condition is one of the best ways of cracking a cylinder head I know!
Hopefully you've got away with it this time.

Sat Dec 30, 2006 8:31 pm

FWIW, I removed the thermostat and now all pipes are hot. Think I need to change coolant temp sensor but I am more comfy that it is cooling properly.

Thanks.

Sat Dec 30, 2006 10:06 pm

Glad to be of help... at least you now now the thermostat needs replacing rather than an expensive pump etc...

Mon Jan 01, 2007 4:49 pm

Ah, pumps arent that expensive, I got 1 4 60 euro cos the bearing went on the shaft. Bt I hav another problem. Not overheating but the opposite.The car stays cold the whole time unless stuck in heavy traffic with the heater turned 2 cold. It doesnt really go past the edgeof the cold mark with normal driving. I was thinkin I need a new stat os the 1 in itcould be stuck open. Ne1 agree r hav neother ideas