Water Pump Knackered?

[R1 Indy]

Hi Guys,

I have another issue with my S2000

After piecing my engine bay back together after a small oil filter fire, i changed the coolant, only i noticed there was rather little coolant left. (temp always fluctuated a bit, so could be why)

I filled the rad back up got it bleed, when i noticed steam coming off the radiator once engine was up to temperature, so looked like i had a radiator leak

So i have now changed the radiator, so no leaks here, got it bleed, so thought things were good. Only the other day i noticed the heaters had lost their heat.

So checked the coolant, no obvious leaks, but obviously air in the system.

No matter what i do i can't get the air to stay out! i have read how to bleed, but the air just comes back


A few things noticeable:

1: there is a rattle coming from around the middle of the engine, near the water pump? Rattle gets louder with revs.

2. There is basically no flow at idle? if i open the bleed valve at idle nothing comes out? same with the rad cap? Unless i add a good few revs there does not seem to be any water flow?

3. it occasionally sounds like I've got a supercharger, when i start her up, and especially when i shut her down, i get this whoosh sound? Infact almost like a vacuum cleaner.

I would imagine its still on the original pump, so would be 13 years/90K miles old. Its Camchain so wouldn't have been replaced with a belt change.

Does this sound like the water pump? could this cause me bleeding/coolant issues?

There has been no signs of overheating on the dash dial, but it has been pretty cold outside!

Cheers

[james_gt3rs]

Are you still leaking coolant?

[R1 Indy]

There is no obvious leak, if it is leaking i can't see where, i can't really see the pump without removing the air box etc.

My main concern is that there is no flow at idle/low revs? or is that normal?

[littleredrooster]

R1 Indy said:

No matter what i do i can't get the air to stay out! i have read how to bleed, but the air just comes back

If you mean that the coolant level keeps dropping, I think you'll find you have a leak rather than a need to bleed.

Knackered water pump sounds like a prime suspect given the other symptoms.

[morgrp]

Sounds like an airlock from a leaking headgasket - I'd doing a pressurisation test - running low on coolant could have damaged it - you mention lots of tell tail signs - poor heater, poor flow, temperature gauge fluctuating. - what happens is exhaust gasses push through into the cooling system creating an airlock that is more noticeable under load this causes the temp gauge to creep up then drop again when the engine is off load and the airlock subsides. Having said all that, it could be a simple case of an air lock from swapping out the radiator - Jap cars can be a pain in the arse to bleed as can french ones too.

[McSam]

A compression test does sound worthwhile, and provided you can get to the spark plugs easily enough it's very quick and straightforward. Then you'll at least know how serious a situation you're in. I would avoid running it in the meantime, but then, I've been given and ignored that advice before and got away with it.

Your symptoms sound a lot like you still have a leak. As coolant comes out, it's replaced by air, hence your dropping levels and perpetual airlock.

There's meant to be flow inside the engine, not out the top of the system! I wouldn't expect water to go pissing everywhere as soon as you open the bleed screw or expansion cap, certainly doesn't on my car so don't be concerned about that. I'd be more worried if it did, this being a sign of combustion gases escaping into the coolant and overpressurising it.

Coolant leaks are usually obvious because it stains well, but if you can't see anything, my route would be inspect it as far as possible including up on stands to get under it, do a compression test to check the head gasket is OK (*), then if I haven't found anything lob some K-Seal in to see if it can cure whatever tiny leak exists somewhere.

Compression test will NOT pick up a waterway-to-outside-air leak, only leaks around the cylinders. It's quite rare and should be obvious from looking at the engine, though.