The bearing in mine is past is best with a slight wobble at the pulley with the belt off. I'll probably replace the tensioner and idler while I'm at it.
My existing pump seems to have next to no flow at idle, virtually nothing from the bleed pipe that goes from the rad to the top expansion cap, but it's fine with a few more revs.
Ages ago i read that some pumps offer a better flow rate at idle than others but for the life of me i can't find the thread anywhere! It sounds logical to me that you want a decent flow through the radiator to keep the engine running at a sensible temp if you're sat in traffic etc. Increasing air flow is no good if the coolant isn't getting round the engine at a decent rate
Any thoughts welcome! Am I overthinking things as usual?
Cheers

Standard pump works absolutely fine providing the rest of the system - esp the rad - isn't full of crap.

When you say standard, do you mean oem, or genuine?

I've used a few, none from a franchised dealer.
One was a 'must have now' as I'd gone to Brum to sort out a problem on my eldest's car. As I got off the M6 temp gauge shot up accompanied by steam from under the bonnet. Bearing had gone on the pump taking the seal with it. Luckily his digs were less than a mile from the junction.
The nearest Partco were useless as they insisted the pump was X not Y & after some argument finally told me they didn't have either in stock anyway. I was not amused.
BLRS had stock & IIRC came in a plain white box so no idea of the make.
Did have an issue with plain box ones on another occasion. Leaked from the pump nose immediately after fitting & the replacement from the same supplier & batch did exactly the same. Got another from another supplier & no issues. Both suppliers are local to me & I was given to understand there was a seal issue with the first ones.

kermit_rr said:

The bearing in mine is past is best with a slight wobble at the pulley with the belt off. I'll probably replace the tensioner and idler while I'm at it.
My existing pump seems to have next to no flow at idle, virtually nothing from the bleed pipe that goes from the rad to the top expansion cap, but it's fine with a few more revs.
Ages ago i read that some pumps offer a better flow rate at idle than others but for the life of me i can't find the thread anywhere! It sounds logical to me that you want a decent flow through the radiator to keep the engine running at a sensible temp if you're sat in traffic etc. Increasing air flow is no good if the coolant isn't getting round the engine at a decent rate
Any thoughts welcome! Am I overthinking things as usual?
Cheers

Click to expand...

All the water pumps from an original manufacturer that are made for your vehicle ( what ever that is) will have the same flow rate by design, a low or non- existent flow would suggest the pump impeller isn't spinning.