Cooling System Issues

[kod81]

Hi,

I bought my E30 318i about 18 months ago. She's been made SORN the day after purchase and parked in my garage. Since then I have been doing some work on her at my own pace.

Recently I started working on replacing my timing belt and , by extension, the cooling system. I drained the fluid and it was very brown and muddy at the end of the flow. I think the previous owner used mostly water as the stuff that came out didn't look like a coolant. At the bottom of the radiator there was plenty of a muddy looking sludge. All very smelly too. I believe it's mostly rust and internal corrosion due to an incorrect coolant (or the lack of it). There seems to be NO signs of oil or milky colors.

I have also noticed that radiator was previously fixed with some sort of a internal sealant. Horrible stuff and seems to be just everywhere: at the bottom of the rad, inside the hoses, behind the thermostat. There are build ups in corners and loads of little white bubble balls around the seals.

When I removed the drain plug from the engine block, nothing came out so I stuck a screwdriver there and punch a whole. Obviously the fluid went everywhere, but this time I was quite happy it was looking very much like a water and not a coolant.

It was a real pain to get the thermostat out, it has seized. Then i pricked out these sealant stuff build ups.

I haven't managed to remove the water pump yet. I am currently experiencing the horror story of breaking off one nut in the lug hole and actually breaking the other lug casing off. It has properly seized to the block. So far, hammer, wd40, pipe wrench doesn't help so I just keep soaking it in a penetration oil for now and trying to wiggle for the past 2 days. I haven't tried appyling heat. I suspect that water pump has corroded to the block.

Anyway.... I have sources all the replacement parts including the radiator, seals, water pump, thermostat, hoses, plugs, etc. the whole set really.

Unfortunately, I think there's plenty of sludge and that bloody sealant in the engine block, so how can I flush it having all accessories (apart from water pump) off? That's including the accessory belts, water pump pulley, radiator, hoses, speed sensor, distribution cap, rotor arm, top timing belt cover... all the bits and pieces to do a timing belt change job.
I was thinking of using a garden hose, but a water won't do much of a cleaning job on it own, would it? I can't really run an engine, besides I wouldn't like running a cold water on a warm engine not to blow a gasket.
Sorry for the long story but an advise would be appreciated.

Also, to add. When I was running the car in my garage or in and out the temp was acting as expected but still I am glad I spotted the problem and planned on replacing the parts.
Thanks,
Regards,

[Brianmoooore]

Sadly, many E30s have gone through the phase of being owned by the penniless, and cooling systems in this condition aren't that uncommon.
M40 water pumps can be a challenge, and ultimately, you may end up removing it piece by piece if you're unlucky.
Flush out as much as you can with a hose, but take care never to force water through the heater system in the wrong direction, Correct flow is upwards from the bottom stub pipe in the engine bay to the top.
After that it's just a matter of running it for a short time with a flushing additive in the water (central heating cleaner works well), before thoroughly flushing out with water. Repeat until you're happy, then fill with 33% coolant mix.

[kod81]

Thanks for the prompt reply. I didn't want to go on too much about the water pump story, but so far it is a hell of a challenge. Therefore I will wait with flushing until I get it out as, as you have said, I may end up removing it in pieces.
As I had to punch a hole through a sludge, after removing the drain plug on the engine's block, I realized the insides must be dirty and they must be cleaned as much as possible.
So, can I just plug a garden hose to the bottom stud pipe with my engine off and run water to the top then catch it with an another hose? Then do the remaining procedures you have listed above? That's the part I am not sure off.

[suedenim]

I had the same problem with my M40 waterpump, the lugs for removing are only of use once you've broken the initial seal, otherwise they're not man enough and break first.
I ended up using a drift to spin the pump around back and forth, driving it out a fraction at a time. Don't be tempted to prise it out once it's out a little as it will damage the block, as I'm sure you realise. Good luck, you'll get there.

[clipper]

When my M20 E30 was returned to me after being stolen it had a blown HG and was full of mayo.

At least on the M20, the access to the block behind the water pump is pretty open and wide, so I extended the handle on a bottle brush and shoved it into the block and twisted it around. It seemed to help get extra sludge out.

If its that bad I'd just put supermarket coolant in at first, run it for a few hundred miles then flush again and put some proper coolant in it.