Cooling problem - Safe to move?

Tue Mar 18, 2014 8:45 pm

Okay, as soon as I fix one problem another two appear.
Now that I've got the car running again ready to move her to a different garage, I've noticed that there is an issue with the cooling system. To give a quick heads up I fitted this engine a while ago after purchasing from one of the zoners here but it hasn't really had a real good drive yet.
Now I've read through the Wiki guide about the cooling system to try to ascertain what the problem is but I'd appreciate some input from you guys.
Once started and left to idle for a few minutes she quickly reaches the half way mark on the temperature gauge. Much quicker than I remember it doing so. Now I've removed the thermostat for the time being to eliminate it from the equation.
When I put the blower heater on then warm air comes through but only for a matter of seconds which suggests there maybe an airlock?
But I've also noticed that the water in the expansion tank doesn't appear to move much? I would expect to see at least some coolant coming back through the expansion tank feed from the radiator but there is none that I can see? This to me suggests that there may be a blockage in the radiator, does that sound plausible? I thought it might be the water pump but the Wiki says if the system is pressurising then the water pump is usually ok. And this is definately pressurising, too much in my own opinion. If the expansion tank cap is left off while warming up the coolant seems to quickly fill up the tank and overflow, which again suggests an airlock or blockage of some sort?

I realise I will probably have to systematically check each part of the cooling system to determine the problem, and of course in the back of my mind is the possibility that the head is cracked and not known about when it was sold to me.

But my question is this, given all this information, would it be safe to drive the car 15 miles to another garage if at least 80% of the journey is along a motorway so in theory I shouldn't drop below 50mph? Or should I first ensure that the radiator isn't blocked so that it will be cooling sufficiently??

Your thoughts and comments are welcomed.

Tue Mar 18, 2014 8:49 pm

If there's been an engine change, then there's a good chance the heater pipes have been connected the wrong way around at the bulkhead. Pipe from the back of the head goes to the lower stub, which is not the way they lie most naturally.

Tue Mar 18, 2014 8:53 pm

Also, I have checked the pipes to the blower heater matrix and they are attached correctly, back of head to lower pipe on bulkhead. I also don't think the viscous coupling is functioning as it seems to have no effect when it's warm.

Tue Mar 18, 2014 8:55 pm

We must have been typing the same time there Brian lol. Yeah they are correct. What would you do in this situation??

Tue Mar 18, 2014 9:02 pm

Viscous coupling rarely needs to lock up, especially at this time of year. it's only needed when you're stopped in traffic for some time, or in slow moving traffic in hot weather. Heater full on almost makes it redundant. (Assuming you have a working heater, of course.)
If there's an air lock it can be released by pulling off the top heater hose, let coolant flow from the hose and the stub, then refit it.
You will either have to fill the coolant bottle to the top or lightly pressurise it, to get the coolant to flow.

Tue Mar 18, 2014 9:25 pm

Is that where the airlock normally sits? I'll do that and see if that helps. Is there a good and easy way to test the radiator? And would a problem with the heater matrix cause similar issues? For instance if it also had a blockage of some kind? Sorry for the nth degree but my car is still a couple of miles away and I need all the instruction I can get so I can work through the list.

Wed Mar 19, 2014 11:28 am

Anyone?

Thu Mar 20, 2014 7:58 am

Water pump?

You sure you have burped the air out of the system correctly?

Thu Mar 20, 2014 11:43 am

Well I did my best but there still may be a bit left. And I also think it could be the water pump. I will probably have to wait until next week before going through the process of finding out what is wrong, so all advice will be listened to. I have a spare heater matrix and a water pump somewhere, it could also be the radiator is a bit blocked, I don't have a spare radiator though.
Thanks for the reply

Thu Mar 20, 2014 12:43 pm

I would bet £100 that a coolant change will fix it and the rad is definatley not the problem, put a new thermostat in while you're at it.

http://www.e30zone.net/e30zonewiki/inde ... _Servicing

Thu Mar 20, 2014 3:48 pm

Yeah I planned to change the coolant when I was sure there was no need to empty it again as I have no facilities to catch coolant for reuse. There is some anti freeze in it but not a lot. I think I will check that the flow is good through the heater matrix, then check out the water pump and radiator before refilling with new coolant to the correct mix. Have you an easy way to test the pump? Or do I have to remove it for a proper inspection?

Thu Mar 20, 2014 5:02 pm

Hmm, not really the only 2 quick checks I know of are 1) Look under the car and check for water seepage out of the pump. 2) Squeeze and hold the top hose checking for rigidity/pressure build up when the engine is running, if there is none then potentially a dodgy pump but there'sno garauntee that is the pump!

I guess if you were to replace the pump (not terribly expensive) you should replace the other bits like timing belt, tensioner, spring. So a bit of a job there!

Sorry, will it leave up to you.

By the way, do you have to catch the coolant for re-use? Just catch it in an old bucket and dispose of safely (away from Cats or Dogs haunts) and then use fresh stuff.

Thu Mar 20, 2014 6:52 pm

Have you bled it from the heater pipe yet?
If you decide to check the matrix for flow, presumably with a hosepipe, ONLY connect the hose to the bottom bulkhead stub, so that water flows from bottom to top.

Thu Mar 20, 2014 7:23 pm

No Brian, I haven't managed to get to it as it's a few miles away and I wanted more to check. I was hoping to try to bleed it in the way you described and hopefully at the same time check the flow through the matrix.

Thu Mar 27, 2014 1:20 pm

Ok update on this, I spent about 3 hours yesterday and it appears that it was an airlock. I managed to get the coolant to circulate better and it now heats the matrix radiator and continues to stay warm. I assume that the water pump works ok from that. I think I will still bleed the brakes before I take it to it's new home. As I will be doing it solo, are there any tricks to this? And am I right in thinking that I bleed OSR, NSR, OSF and NSF in that order?

Tue Apr 01, 2014 10:30 pm

No answer was the stern reply? Well no matter, the brakes seem to have firmed up by themselves and I have an idea why they went a little soft in the first place. I believe that the surface rust on the discs and drums is what caused this softness. As soon as I drove the car back and forth up and down the driveway and tested the brakes, it seemed to return to what I remember them as.

I finally was able to top up the antifreeze today, it's not very strong but it will do for now. I haven't fitted the thermostat yet though as I'm only moving the car 15-20 miles where she will stay for a while anyway. But as far as I'm aware she is ready to be moved and the date is set for this Thursday so wish me luck. Most of the journey is along the M4 so it should be plain sailing.