Confirm this is water pump symptom?

[eko]

Ive noticed the last few times ive driven the car that the heater sometimes goes cold when sat on idle in traffic/lights etc.
Soon as revs are back on it goes normal.
Pump was new around 8 months ago and new coolant at the same time.
No signs of overheating or anything just the above issue.
Travelling up to Manchester in it later this week so need to sort it asap.
Is this the water pump on its way out?

[DanThe]

Could be low coolant or blocked matrix also, what brand is the pump?

[eko]

KWP pump mate

[e30-EVN]

I'm havin the same issue as Tony, it was completly fine before I suffered catostrophic water pump failure yesterday and changed it....
Bleeding her back out was a royal pain in the arse and she was playing hard to get!
When driving, the heaters are lovely and baking but not so hot at idle until reved or driving. I'm thinking a small air pocket in the matrix??

I hope so

[Brianmoooore]

Sounds like a minor air lock to me. Bleed it at the top heater hose.
If the problem returns, the next, and more important, question, is "where is the 'air' coming from?"

[e30-EVN]

I've tried to bleed via the bleed screw on the rad several times but no change. As said, before the water pump change the heaters were fabulous

What's the best way to clear a small air pocket in a matrix? And by top hose, what exactly do you mean Brian?

Thanks by the way

[Supafly]

I think that the top hose brian is referring to is the upper of the two pipes that come out of the bulkhead, jack up front pull off pipe and let it run until its clear.

[e30-EVN]

With an m52 engine in place lol

I "may" be able to get to the jubilee if I take the wiring box cover off

[eko]

Swapped the pump on mine today for peace of mind.
No sign of any real wear or play in the one I took off but new one and coolant seems to have sorted it anyway.
Im confident itll be fine for its roadtrip

[Supafly]

When I typed it I was picturing an m20 in my mind although I have an m52 in mine too

I must have been lucky with the combination of flexi's and extensions I used as mine went on fairly easily. Either that or it was such a bad memory my brain has decided to blank it out and think of nice and easy m20's

[e30-EVN]

Yep, that's it...... Nice and easy m20's lol

Bit of a squeeze with these beasts

[DanThe]

Swapped the pump on mine today for peace of mind.
No sign of any real wear or play in the one I took off but new one and coolant seems to have sorted it anyway.
Im confident itll be fine for its roadtrip

Same brand pump? Let us know how you get on mate

[eko]

well it did the 300 plus miles with no problems at all.
Filled up with 68.50 fuel,ive done 344 mls and gauge is still showing just under quart mark.obc showed best mpg at 45.8
Well happy with that!

Fitted another kwp pump dan.
Temp and heater as it should be

[Brianmoooore]

Wonder if the old pump was drawing air in past the seal as the cooling system cooled down?

[eko]

just driven the worst 120 miles down the m6.down to 1 lane in places.very sketchy driving,thougth i was going to spin out a few times.
My car has behaved brilliantiy though and ive seen 47.1mpg on my obc.accurate i dont know but im amazed to see anything close to that