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316 overheating problems - Richard331
Ok heres my boring story im hoping someone can help me.

I bought mt BMW 316icompact 1.5 years ago. When i first bought it i noticed it was running at alot higher temperature than my Corsa 1.5TD. Assumed this was normal. 2 months later car severley overheats on the motorway i pull over and let the car cooldown coming off at the next exit and driving home carefully without the car overheating. Thermostat was jammed shut so i took it out as i was told i dont really need one till winter anyway. Still didnt fix the problem, so i replaced the radiator and water pump to then find out that the gasket needed replacing.

I was told at this point it was better to get a new engine because the local garage said the engine had severe problems. So takes me a few months to replace the engine to which im all happy about again as ill soon be back on road (They disconnected the heater matrix as one of the pipes coming out of it corroded, so they by-passed it). Car passes its mot but i notice that it gets to half temp guage way pretty quick after about 3-4 miles. Continue to drive etc and then eventually after about 20miles goes into the red again. Engine is severely pressurised as before. So this time ive had the water pump replaced again, just incase when i got my engine change they didnt change the water pump and the radiator cap. Still the same problem.

The main problem now is that it doesnt seem like the water is flowing back out of the radiator into the engine. Now ive been told this can be two problems either the radiator is blocked or head gasket is gone again. Or could the heater matrix have somehting to do with it.

Any help will be appreciated as i dont fancy replacing the head to only find out that it wasnt the problem in the first place. Does anyone think the matirx would be responsible.

Thanks for reading this wall of text.


Edited by Pugugly {P} on 08/01/2008 at 18:31

316 overheating problems - thomp1983
have you made sure the cooling system has been bled of air properly? and has it had a compression test? also get a sniffer test done that would rule out h/g. do you have any of the normal h/g symptoms such as mayo like oil, regular water loss etc.

316 overheating problems - Richard331
It was took into a garage where they backbled the system. No typical signs of head gasket gone except water loss but i know thats because the radiator cap lets it out when the pressure gets too high.

Its going in for head gasket tests tommorow and if they rule that out im completley stumped.
316 overheating problems - janen
I've been having the same problem - started in Jan 08 with overheating, the local garage bled it and pressure tested. No leaks found and the thought was that there must have been an airlock. Couple of months later started overheating again - I kept checking the radiator and found it needed topping up - pretty substantially, had to keep topping it up for about 4 days running. Solved the prob - until last week. Questionwas where was all the liquid going? Mine was also really pressurised when trying to undo the radiator cap - even when from cold. Took it back to garage yesterday - when they pressure tested again, no leaks. They have also concluded it must be the head gasket and mine's going in next week. Did it turn out to be the head gasket on yours? (FYI: mine's a 96 P plate 1.6i)
316 overheating problems - Peter.N.
A leaking head gasket doesn't in itself cause overheating, its due to the pressure expelling the water and causing an air lock. The other usual cause is a furred up radiator - but you have already changed that.
316 overheating problems - JimmyMcJam
It's the head gasket. I've seen this all too many times. I had an R reg 316iSE with exactly the same symptons. 2 friends have had it and there are countless references all over the net of this problem, it is apparently due to the early gaskets not being durable over long periods of time to oil pressures or something because they were made of a silicone compostie and not just silicone.

My symptons ran over many months starting with the car overheating in a McDonalds drive-thro and blowing the inlet on the back of the engine block. Then a few weeks later it overheated whilst at traffic lights, all of a sudden just shot up. The fan never came on during any of these situations. About a month after this and asking several questions and bleeding the water system etc I changed the pump and thermostat. Again the early pumps were of a bad design and the pin holding on the finletts makes it snap the plastic. It was shattered inside my engine. After changing these two things the car ran smoothly, the fan came on and it did not overheat.... but then I drove from the South of England up to Sheffield (approx 250miles)... I checked the levels and water temp all the way. I got stuck in traffic jams for 1.5hours and nothing! the fan was kicking in and the car was not overheating, then as soon as I pulled up at my friends front door I noticed steam. My friend let the engine cool down (he's a mechanic) and opened the expansion tank, very carefully, no hissing or bubbling but boom, the cap flew a good 10ft in the air and hot collant went everywhere. This cracked the radiator which we bodged with instant gasket to get home. I then changed the radiator and when I started the car again it bubbled over and white smoke came out the exhaust... head gasket/cracked head. Tried Wondaweld but it didn't work. Ended up changing the gasket myself, which only ook about 3 nights after work, new gasket set is about £60-70 and now it runs like a dream. Sent the head off for checking and got it skimmed by a friend, normally thats about £80-100.

So in short, its a dodgy head or gasket!!!
316 overheating problems - JimmyMcJam
Change of plan, I feel like an idiot now but at the same time I think I can help.

Car ran fine just like Richard331 said at the start after the gasket change. Mine then started overheating again. I had already changed my radiator but the actual water tubes on the new one were a lot thinner and appeared to be blocked, again like Richard331 asked. I took the major option because I knew the only thing blocking it would be Wondaweld so I put Caustic Soda through it. Don't try this if you don't know what your doing! It super-heats and corrodes any blockages but you can't leave it in there for more than about 5 minutes because it WILL melt the radiator, and also make sure the radiator isn't in the car when this is done... Loads of red goo came out the radiator and water started to flow evenly, the engine again ran up to temperature fine and went smoothly, I then took it out for a drive and noticed the heat guage nudged up twice, it literally nudged then went down again so after about 10 miles I pulled over. Popped the bonett and the fan was working. I could hear a glugging/sucking noise and found out the top water hose flange (mount) had been cracked and air was leaking in the system. I let off some pressure and drove it home and ordered a new one. Arrived next day, fitted it, started the engine and it bled through but the system was still becoming pressurised. I realised the heater matrix pipes at the back were not getting warm... which means no water is flowing through them. I'm in the process of sorting it out now, I can get water to trickle through the pipes but not flow.

In short, check the radiator has no blockages, try Rad-Flush, check the heater matrix is warming up, you'd know if it wasn't because the fans won't get hot in the car, and warm the car up and listen for any gurgles anywhere. If the engine is getting pressurised still and the head isn't gone, there is a blockage or air leaking somewhere! I'm getting to the end of my tether with this car! I've spoken to BMW as well and the only advise they gave, which may also be helpfull is this:

"Bleed the radiator very slowly, topping up gradually, rock the car to try and release air pockets, get it up to temperature and as soon as the fan kicks in, seal it up, shut it off, leave it over night and repeat 3 or 4 times"

I was informed that E36 are well renowned for being a pink fluffy dicefor bleeding through and unfortunately its a case of trial and error.

Hope something here helps.

Edited by Dynamic Dave on 08/08/2008 at 10:09

316 overheating problems - JimmyMcJam
Also the E36 head gasket was redesigned because the rear cylinder, or 4 on my car was constantly overheating, they made the holes smaller around the water jackets for 1 2 and 3 so more water would flow to 4, they also changed the material so it didn't decompose.
316 overheating problems - Richard331
Hi guys just a quick reply. Found out what the problem was eventually and of course it was a mixture of the head gasket and believe it or not thermostat housing. The garage i took it to did the gasket however the car continued to overheat. The garage was really confused and had the car for a further two days. Apparently once they replaced the thermostat housing and re-bled the car it was fine. The thermostat housing was faulty and apparently drawing in air causing pressure to build up.

Its been 8 months now and ive had no more problems touch wood.

Thanks for all your advice.

Ive got another question as well. My car has no spare and im gonna buy a spacesaver for it. I currently have 18inch alloys on does it matter what size spacesaver i get?

Edited by Richard331 on 08/10/2008 at 22:20

316 overheating problems - Dude - {P}
Have been following this thread from the outset and it is always appreciated when the OP gives us all an update to the problem, which is much appreciated and very helpful.
Thank you Richard331.

As regards your spacesaver, you will need to get an 18" without question.
316 overheating problems - millan
How much did it cost? because I think mine has just done the same!!!

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