Water pump

Hi,

My 83, 635 has just developed an overheating problem and I suspect a duff water pump.

If anything it had previously been running a little cool and under the halfway mark on the temp gauge. It kept making an occasional squealing noise, similar to a slipping fan belt.

Last night I noticed that the gauge started to climb and climb and climb. I obviously knocked the engine off.

I dont think the gauge is defective as I pulled the bonnet and the overflow on the expansion tank was doing its job!

Would anyone concur with my suspicions that its the water pump which has given up?

Mileage on car is 130k.

Is it a hard job on the M30 engine?

Sohlman,

Hi, I picked up your reply in the coupe section, many thanks.

I guess I should keep the topic in this thread to be correct. Not going to look at it now until the holidays are over, are new water pumps expensive?

When the engine is on the cooling fan is turning, is that correct?

What were the symptons which prompted the replacement of your water pump?

I do hope that the gasket and head are ok. Cars eh? you gotta love em eh?

Help!!

Had a look at the overheating problem.

The plot thickens, Im satisfied that the temp gauge is working ok.

The engine runs hot and hotter etc,etc the gauge gets easily up to the 3/4 mark. Now then... When I turn on the internal heater on hot, its blowing ice cold air.

I then move into the engine bay to find that the engine is red hot but the radiator is ice cold, the top hose is barely warm. Ive changed the thermostat to no avail.

My mate came round and provided the prophet of doom role and came up with the usual head gaskets gone idea.

Im not so sure, I have no mixing of oil and water and the car wasnt using or losing coolant either.Ive flushed the radiator and had all the pipes off looking for blockages etc. Im baffled!

Changing the water pump looks like fun, It looks like the radiator will have to come off to allow the viscous fan to come off. I want to be 100% certain that its the water pump before I start the job. Is there any quick or easy way to test the water pump in situ?

I know you were unlucky with yours, but genearally post march 1983 series 2 6's have pretty tough heads. Post 85 cars are even stronger mind you.

As for the labour of love comment that's from Iain before he had his engine problems. I am not sure what he will be saying now.

Back to the waterpump/overheating debate. If you are going to change both your water pump and viscous fan coupling i would suggest running a low pressure hose through your radiator whilst it is off. This will serve two benefits. 1/ you will flush out a load of crud in it and 2/ if there is a blockage or even a hole this should soon make itself apparent. Just don't put any more pressure than a running tap as they are delicate inside.

On the M30 3.5 engine, it runs with a timing chain that is nigh on indestructable. They only need to be changed if they get noisey. Although i agree with your sentiment old shape.

Sorry about your bad news Big Vern. Horsetan knows all about the problems of head gaskets on sixes. As a matter of interest who are you going to see about your car? I was a bit worried when you said the car had overheated as the M30 does not like that. The only other culprit i can think of is that you have two problems. 1 being the waterpump/viscous fan coupling and the second being leaking injectors which clear after a quick blip of the throttle. Good luck and keep us posted

Big Vern wrote: Im going to use an independant called "prestige German cars" based in South Shields in Tyne and Wear.

You must be talking about Jon Morgan. He was recommended to me by Motorforce. Haven't dealt with him but heard he's good. I'll take my 635 to him if (when?) it needs anything.

I live just across the river in North Shields.

Got the big lad back today! I must stress that I did tell Jon to take his time with the car as their was no urgency on my part.

Anyway, what can I say, fantastic, cracking bloke who clearly loves his work and is an enthusiast. Standard of work is excellent and he clearly has a lot of pride in his work. I have to say that I found the bill very reasonable indeed. I would certainly recomend him without reservation from my initial experience with him, feel free to drop my name (Tony Newton)

Jon Morgan, Prestige German Cars, 0191 4566623.

As for the car, its been absolutely transformed, it really does feel like a different cat indeed. Now then, need to start saving for the other bits and bobs that need doing.