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Motorway Overheating.

Posted: Sat Jul 10, 2010 1:20 pm
by yellowmellow
MY E30 (eta) is overheating speed on motorways, I thought this was a bit strange with the amount of air going in the front !

Anyway this must mean something else is afoot. Sometimes it does go close the red around town- but can be made to drop by turning heater up full blast. coolant does need topping up now and then Would I by right to think ;-

air block- thermo- water pump oh oh !!!

happy for any help :cry:

Re: Motorway Overheating.

Posted: Sat Jul 10, 2010 1:24 pm
by Brianmoooore
A new radiator would probably solve your problems, if you're running the original.

Re: Motorway Overheating.

Posted: Sat Jul 10, 2010 3:59 pm
by psychochild187
or a leaky hose somewhere.
eg the small one on the bottom of the thermostat housing.

Re: Motorway Overheating.

Posted: Sat Jul 10, 2010 8:07 pm
by yellowmellow
Thanks for you quick replies chaps,

I just noticed with my Bentley manual in hand that my high speed fan relay was missing from my fuses box. I,ve put another one in now. But I will also check the rad and hoses.

Cheers and THANKS again,
:D

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 12:21 am
by Cypriotgeeza
willnz wrote:At motorway speeds, you should not need any fan to cool the engine. If this is the only time you experience overheating, then, as Brian says, it is most likely your radiator that is at fault.
either that or maybe your water pumps so knackered it cant keep up with the demand it needs to pump..I've seen that before on a few cars!

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 1:06 am
by magpie
is the pass side carpet wet?and if you've had a large top up of coolant have you bled the system?

try letting it tick over and look for leaks on the ground.

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 1:28 am
by psychochild187
high speed fan relay .?
but the radiator fan is mechanical. and not electrical

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 10:07 am
by Cypriotgeeza
psychochild187 wrote:high speed fan relay .?
but the radiator fan is mechanical. and not electrical
yea probably why it was "missing" :mad:

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 10:31 am
by 12345kevin
Had exactly the same problem with mine, high speed or long hills brought the temp up. Change of Rad cured it :-)

Re: Motorway Overheating.

Posted: Sun Jul 11, 2010 2:08 pm
by bmw9818
check your water pump my one was so knackered the fins had completely worn, there was literally nothing left!

Re: Motorway Overheating.

Posted: Mon Jul 12, 2010 10:04 am
by clipper
12345kevin wrote:Had exactly the same problem with mine, high speed or long hills brought the temp up. Change of Rad cured it :-)
Having exactly this issue at the moment.

Yesterday I poured a bottle of nitric acid into the radiator (out of the car) to see if I could unblock it, seemed to be an agressive cleaner 8O .
I'll let you know if it has worked when I get it back together....

Re: Motorway Overheating.

Posted: Mon Jul 12, 2010 10:34 am
by bimanut
:eek: Hope you`ve flushed it well!

Re: Motorway Overheating.

Posted: Mon Jul 12, 2010 11:35 am
by clipper
bimanut wrote::eek: Hope you`ve flushed it well!
Flushed it with fresh water before fitting it back in the car, now the coolant circuit has some flushing additive in fresh water, so if any did remain it will be extremely diluted by now.

SHould be OK. :?

Re: Motorway Overheating.

Posted: Mon Jul 12, 2010 8:20 pm
by yellowmellow
Cheer,s to all the above for your help,

I reckon it must be Rad or water pump then as I,m showing no Leak,s and no damp carpet.
Wondering what that relay is for and why it was missing (according to Bentley manual )anyway.
I wonder if a mild rad flush could help or sod it i.ll do them both..
Thank,s again geezers!

Re: Motorway Overheating.

Posted: Mon Jul 12, 2010 8:24 pm
by yellowmellow
yeah clipper let me know how it goes 8O

Re: Motorway Overheating.

Posted: Tue Jul 13, 2010 7:53 am
by clipper
Well, yesterday I bled the system properly and let the car heat up with the rad flush in there.

I had previously used a good quality rad flush and it had left what seems like a large amount of crud in the rad. I think they're OK for general use, but for cleaning a rad after a H/G failure they don't seem to be strong enough.

The only problem I noticed now is that the gauge was very slightly over half way when the thermostat opened. I took it out and it has 80ยบ stamped on it, but in a pan of water it wasn't fully open until the water was boiling. I doubt that this was caused by the nitric acid though, the radiator seems to have survived that attack rather well.

In order to eliminate the causes I will put the same thermostat back in and run the car on the motorway to test if the radiator acid attack has helped, if that doesn't work I'll try a new 'stat.

Assuming one of the above fixes it, I'll let you know.

Re: Motorway Overheating.

Posted: Tue Jul 13, 2010 7:57 am
by clipper
One last comment.

If in doubt, do what Brianmooore says.

I bet you that in less than a month I end up doing exactly that anyway..... but it's good fun trying to find ways around spending money on stuff.

Re: Motorway Overheating.

Posted: Thu Jul 15, 2010 8:29 pm
by clipper
Didn't work.

New radiator time ! :?

Re: Motorway Overheating.

Posted: Thu Jul 15, 2010 11:04 pm
by yellowmellow
Yes clipper-

I think that,s going to be the way to go mate, I,ll do the water pump -timing belt- thermo at the same time so it job done.
By the way mate, do you know where the engine number is on the actual engine as this eta engine of mine was put in by my mate and all I know is it,s a 1985 (525) I think there was two out that year. I know need that info to by parts.

cheer,s pal :?:

Re: Motorway Overheating.

Posted: Thu Jul 15, 2010 11:44 pm
by jmc330i
Cypriotgeeza wrote:
psychochild187 wrote:high speed fan relay .?
but the radiator fan is mechanical. and not electrical
yea probably why it was "missing" :mad:
E30s with aircon have electric 2 speed fans (low and high speed) as well as the viscous fan. The manual will cover most spec of cars so will show the extras.

Re: Motorway Overheating.

Posted: Sat Jul 17, 2010 6:10 pm
by clipper
Just had one last attempt at unblocking my rad.

This time I filled it with caustic soda...... now I have stains on the balcony tiling and a hole in the rad !!! :mad:

I think I'll leave it now and buy a new one :D

Re: Motorway Overheating.

Posted: Sat Jul 17, 2010 6:23 pm
by bobbin1982
well if it wasnt broke.. it is now :mad:

Re: Motorway Overheating.

Posted: Sat Jul 17, 2010 9:36 pm
by Brianmoooore
Caustic soda reacts violently with aluminium. Explosively under certain circumstances!!

Re: Motorway Overheating.

Posted: Sun Jul 18, 2010 9:53 pm
by clipper
Brianmoooore wrote:Caustic soda reacts violently with aluminium. Explosively under certain circumstances!!
8O

It's pretty tough on terracota too.

Re: Motorway Overheating.

Posted: Wed Aug 11, 2010 2:42 pm
by octanejunkie
Good for de-coking 2 stroke exhausts though! 8)

Re: Motorway Overheating.

Posted: Tue Sep 21, 2010 11:19 pm
by yellowmellow
AAAArgh IT WAS THE WATER PUMP> IT WAS THE WATER PUMP> IT WAS WATER PUMP. After changing
thermostat and viscous I was just about to do the rad, mate said pump, I owe him a drink ! :D :D :D

Re: Motorway Overheating.

Posted: Tue Sep 21, 2010 11:28 pm
by Brianmoooore
What exactly was wrong with it?
A new rad will still be a good investment, if the one fitted is the original.

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 7:08 pm
by yellowmellow
Yes brianmooore,
Sorry for late reply, The water pump had loose bearings , (If they are actually bearings) it grinded and rumbled a bit as I turned it in my hands, also it had a couple of millimetres of play too, new one turned sweet and quiet. The needle sits mid way now instead of charging towards the red. Shazz325sport sorted me out neatly since a certain dealer sold me the wrong pump shazz had a spare.( we had all ready pulled knacered old one out). I may still change rad, but I may be going for a 3.5 lump. What do you think of them. And thanks for you help and every one esle too. :D :D :D :D :D

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 7:19 pm
by town325i
yellowmellow wrote: 3.5 lump. What do you think of them. And thanks for you help and every one esle too. :D :D :D :D :D
Please do a search on this rather than having pages of Rav bleating on about how good an M30 boat anchor is :D

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 10:07 pm
by Rav335uk
town325i wrote:
yellowmellow wrote: 3.5 lump. What do you think of them. And thanks for you help and every one esle too. :D :D :D :D :D
Please do a search on this rather than having pages of Rav bleating on about how good an M30 boat anchor is :D
Ignore the hater above, always talks S h i t. :D
Any info you need on the M30 can be found in the engine swaps section, or just ask. :cool:

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 10:17 pm
by Brianmoooore
Rav335uk wrote:
Any info you need on the M30 can be found in the engine swaps section,
Right next to the M50/52 forum!

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 10:19 pm
by Rav335uk
Brianmoooore wrote:
Rav335uk wrote:
Any info you need on the M30 can be found in the engine swaps section,
Right next to the M50/52 forum!
Brian, he was asking of going M30, not plastic coated engines. :D

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 10:44 pm
by town325i
Rav335uk wrote:
Brianmoooore wrote:
Rav335uk wrote:
Any info you need on the M30 can be found in the engine swaps section,
Right next to the M50/52 forum!
Brian, he was asking of going M30, not plastic coated engines. :D
See look even the very wise knows the better engine :D There will be less plastic on my car than ures even when i have the m50 in the bay :D

Re: Motorway Overheating.

Posted: Tue Sep 28, 2010 10:48 pm
by Rav335uk
No SPAMMING !! :twisted: