Water Pump Woes

[David53]

Discovered a nasty rattle from the front of the engine when lifting the throttle slightly....after a bit of a look round it seemed to be coming from the water pump. Slipping the fan belt off and running the engine confirmed this. I also have a leak from the bottom of the pump where it joins the block, a few drips when the pump working but worse when the fan belt was slipped off. I'm assuming it is the bearings wearing out.

As you prob know the 803 pump is cast iron and hard to find - however ESM seem to have a supply of new units so will order one or look into having this one rebuilt. My question is, how risky is it to keep driving the car with a rattly and slightly leaky pump? Have a run planned this weekend of a few hundred kilometres - should I risk it?

[Alec]

Hello David,

it depends on what back up you have as it could go for many miles or die suddenly? Personally I wouldn't go very far in it.

Alec

[bmcecosse]

Depends how bad the rattle is...... What's likely to happen is that the leak will get worse and worse. If you do go - don't do the fan belt up too tightly - 'just' enough to spin the dynamo and pump.

[Neil MG]

David,

I am in exactly the same position! The only difference being I just received a new water pump from ESM, but I don't have chance to fit it at the moment! My journey, Monday evening is only 120km but it is relatively remote around here!

The pump is pretty noisy, (I thought it was the dynamo at first) but I pumped it full of grease and it's been ok for short journeys.

[David53]

Thanks for the advice

Well, the rattle is loud enough to be heard above the engine from the drivers seat with the bonnet down in a garage....not noticeable on the road. Guess I'll have to decide if I want to take the risk....I have ordered a new 803 pump from ESM. Any feedback on the quality of them?

question is why would the bearings wearing out cause a leak from the BACK of the pump? Surely this would be more indicative of a failed gasket. But the gasket was replaced only about 2,000 miles ago when I replaced the timing cover oil seal so can't see why it should be leaking from there?

[Neil MG]

Could the fan belt have been on a little too tight when you refitted the pump? That would account for both bearing and seal failure. Note that the (coolant) seal is also at the back of the pump, so that's where the leak will be.

The new pump looks ok, but I didn't fit it yet. Maybe I can get chance before tomorrow evening!

[mike.perry]

Don't scrap the old pump, I have the address of a company that rebuilds water pumps

[David53]

No, I think the fan belt was OK. About an inch of movement along the longest side. I think it may have more to do with the poor quality of modern parts

Thanks Mike, was planning to have the old one rebuilt as a spare, given these pumps so hard to find. Hopefully there'll be someone in Oz who can do it

[katy]

Methinks the leak at the back of the pump is coming from the weep hole.

[Neil MG]

Well I managed to find a free half hour or so this evening and so I swapped the pumps. The new one seemed stiff at first and I wondered if I would need to run the belt tight and then slacken off once the pump had loosened off. But it span nicely after a few pushes on the starter switch. Went for a drive; no noise, no leaks, no overheating!

My only complaint is that it comes without a gasket and the engine set I got (from ESM) supposedly for an 803 has the wrong one. I made my own from brown paper and it did the job!

I stuck a thermostat in while I was at it as I noticed there wasn't one fitted when I had the head off recently. Hopefully it will warm up a bit quicker; it's not exactly powerful when warm, but when it's cold....

[David53]

I've ordered the same pump, and will have the old one reconditioned as a spare. I am guessing the design was changed for the 948 due to this one not being up to the job - just one more joy of running a Series II I guess!

[David53]

It appears I may have had the belt too tight after all - pulling the rad out and removing the fan reveals quite a bit of lateral movement on the shaft from the front bearings, obviously this is where the rattle is stemming from. Shaft is still nice and firm to turn, but you can wiggle the shaft about quite a bit at the front. This pump was new when I assembled the engine about 4,000 miles ago, so either my belt was too tight or these new parts are not too well built...hopefully the new pump will be superior. Still debating whether to risk my trip this weekend or not.....