Water pump, or not!

J

jim80

Member
 Portsmouth
Well, I haven't been on the forum for ages! But now I have a problem and I hope you guys and gals can help.

My Z4 3.0si has just been in for a service (inspection 2 with brake fluid and coolant change).
I was driving on the motorway yesterday and the temp gauge shot up into the red. I stopped and checked the coolant level and it seemed fine but the heater would not get hot. Today I have spent ages trying to bleed the system to no avail.

When I enter the reg no. into car part websites it come up that I have a mechanical water pump, this I now discover is not the case. Before I stripped it down to have a look I tried the bleed procedure just in case I had the electric pump and nothing seemed to happen.

So now the car is stripped down and lo and behold I have the electric pump. I removed it and thought I better check it before forking out for a new one. We'll it appears to work.

Trouble is now I haven't got a clue what's wrong with it.

Could it just be the thermostat?

Does anyone have an idea or an experience that is similar?


Sent from my iPad using Tapatalk - now Free
 
I've had a similar experience. By the time I limped home (overheated just several miles away) it was working fine again, so no way to diagnose the problem. This has happened twice now, with a couple hundred miles of trouble free in between. I fully bled the system after the first episode. I think I'm going to just go ahead and change the thermostat on a hunch, It's the least expensive part in the system, though hardly cheap. It also seems more likely than anything based on the meagre symptoms I could find. In my experience, bi-metal devices such as thermostats are either incredibly reliable or incredibly unreliable, you never know which one you'll get, it's a gamble every time.
 
Don't think a fooked stat would stop your heater matrix from working. Sounds more like an air lock. Have youtried bleeding the system with the heater set to the hottest setting?
 
GreyZed said:
Don't think a fooked stat would stop your heater matrix from working. Sounds more like an air lock. Have youtried bleeding the system with the heater set to the hottest setting?
Click to expand...

Yes I have done this. I have tried to bleed it for AGES. This time the temp didn't go into the red.

Before this the temp has always stayed bang on centre no matter how hot the ambient temp.

Just two things have happened.

1. The service with coolant change.

2. I went on holiday for a week, so the car wasn't moved for about 10 days.

I think I may have stripped it too soon. I suppose it could've been a lose connection? But I'm clutching a straws really!


Sent from my iPad using Tapatalk - now Free
 
I have one ordered a thermostat as it is the cheapest part. Hopefully this will sort it out. Now all I have to do is find the time to fit it.

Worst part is now I have to drive my wife's car to work! Fiat 500, a mean beast with a 2 cylinder 875 engine, turbo charged no less!



Sent from my iPad using Tapatalk - now Free
 
Jim

Bleeding the coolant system on a slope is a problem also depending on the degree of slope, it traps air in spaces that would normally vent. Can you get the car when re-assembled to a level area to do the air bleeding ?
 
Nelly Welly said:
Jim

Bleeding the coolant system on a slope is a problem also depending on the degree of slope, it traps air in spaces that would normally vent. Can you get the car when re-assembled to a level area to do the air bleeding ?
Click to expand...

I'm waiting for the delivery of the thermostat and will then refit everything. Once I have done this I will put it on level ground and bleed again.


Sent from my iPad using Tapatalk - now Free
 
Really cannot see how a failed stat would present these symptoms. If your pump has failed and isn't circulating coolant then that would add up though. Your heater should get hot even if your stat has failed closed.
 
jim80, I missed the your detail of the heater not working. In my case the heater still worked. Sorry if I misled you. :( :( :( If it helps any, several people have had 'stats go bad, so having an extra one around isn't a complete waste.
 
Well it appears to be fixed now. I replaced the thermostat just to be sure and followed the bleed procedure. This time it worked. Last time I never heard it run so maybe it was a lose connection? The heater works as well so when it's cooled down (tomorrow morning) I will check the coolant level and top it off.


Sent from my iPad using Tapatalk - now Free
 
I've had a cooling issue with my 2.2 2004 Z4. Can someone help me out with airlock bleeding instructions please?
 
Meza said:
I've had a cooling issue with my 2.2 2004 Z4. Can someone help me out with airlock bleeding instructions please?
Click to expand...

OP discovered he had the electric water pump, but I doubt you have that and FWIW the cooling system bleed procedure is totally different - with the electric pump you do it electrically with the ignition key in Position I and the accelerator pedal in the carpet for some time whereas with the mechanical pumps it is a manual procedure.

You should be able to find something in the "How To" posts, or searching E85/E86 problems hopefully! :thumbsup:
 
You must log in or register to reply here.
Back
Top Bottom