Coolant loss and trickling noise when revving 3000+

[Jarlly]

Hi guys

 

I really like my car (2001 1.4 8v MPI, 130k), though it's a little poorly :(

 

It's loosing coolant, though the rate is manageable, 1 litre/month?. Oddly it did 2000 miles in 5 days without needing topping up, but wants a top up every couple of weeks of 'normal' use, which is a mixture of 10 minute journeys and 100+ mile journeys. Fairly obvious coolant loss from the radiator and lower radiator pipe, I plan to replace these at some point. It leaves a small puddle on the ground at night.

 

When I rev it to 3000rpm+, neutral or loaded, I get a noise which sounds exactly like what I imagine air in the coolant would sound like as it's pushed through the engine. Almost like a gently trickling stream. Sometimes with the heaters on hot I get a slight burning coolant smell. Coolant smells and looks ok to me, no mayo on the cap so hoping not HGF.

 

Service history: I added a thermostat to the car when I bought it, never had an overheat, no idea about the water pump or HG being changed, and still haven't got round to a new timing chain (Probably DIY it when it warms up again and cross my fingers in the meantime!)

 

Oil usage is slight, maybe gone down 1/2 a dipstick in 4000 miles?

 

Whilst writing this it sounds quite obvious to me- replace the rad and lower rad pipe and see what happens, I'm just a bit loath to chuck money and time at it when it could be a HGF so wanted a second opinion Would HGF noises be more obvious during load when there's more pressure being generated? Could the noise be my water pump disintegrating?

[rwbaldwin]

I would suspect the waterpump is on the way out and the noise you can hear is 'kettling' (water boiling in the head).

[sepulchrave]

I think what you hear are bubbles and voids forming in the heater matrix, since this is the highest point in the system this is where it happens first, you have a leak and the system is losing pressure, replace the radiator, the bottom pipe should be ok.

Edited 9 October, 2014 by sepulchrave