Coolant Noise

crazylex · May 1, 2005

Has anybody got a clue about this - its been going on for almost a year - and I have nearly succummed to buy a BMW - HELP me before I become another BMW winner (edited now i have one :winky: ) !!...............

Bumped car in July last year - fairly minor, but had new rad, water pump took a hit -had new, plus other bits at the front.

Cars makes a noise over 3500 revs - in any gear and neutral stood still.

Insurance co and Lexus Leeds can not sort it, and I think they are avoiding my calls.

We have all tried bleeding it ( I tried it - didn't work - great photo though front 2 foot in air - I'll post it when its sorted).

Ins co bled the system, with some gizmo that actually forced coolant through, rather than just jacking it 2feet at the front to bleed.

This worked for four miles, now its as bad as ever, It has a similar sound to NOS on Need for Speed Underground. But unfortunately to me sounds terrible.

Lexus Leeds clamped the top heater hose and the noise went (although only tested when stationery)

So we at least know its coolant now -- oh thats after a new cat and a new alternator - thank g at the ins co expense.

Any ideas - or things to try/test ????????

star a · May 2, 2005

Has anybody got a clue about this - its been going on for almost a year - and I have nearly succummed to buy a BMW - HELP me before I become another BMW loser !!...............
Bumped car in July last year - fairly minor, but had new rad, water pump took a hit -had new, plus other bits at the front.

Cars makes a noise over 3500 revs - in any gear and neutral stood still.

Insurance co and Lexus Leeds can not sort it, and I think they are avoiding my calls.

We have all tried bleeding it ( I tried it - didn't work - great photo though front 2 foot in air - I'll post it when its sorted).

Ins co bled the system, with some gizmo that actually forced coolant through, rather than just jacking it 2feet at the front to bleed.

This worked for four miles, now its as bad as ever, It has a similar sound to NOS on Need for Speed Underground. But unfortunately to me sounds terrible.

Lexus Leeds clamped the top heater hose and the noise went (although only tested when stationery)

So we at least know its coolant now -- oh thats after a new cat and a new alternator - thank g at the ins co expense.

Any ideas - or things to try/test ????????

←

if it sounds like air in the coolant, and you def have no leaks, then the water pump impeller could be slightly out of tolerance causing aeriation ( bestway to decribe is like a spinning ships propellor under water causes airbubbles due to friction heating the immediate water around the propellor) the waterpump impellor blade angle is carefully designed to prevent this, but it is possible that yours may be slightly out. However it is a lot of hassle to replace it just to see if it cures it.

crazylex · May 2, 2005

Has anybody got a clue about this - its been going on for almost a year - and I have nearly succummed to buy a BMW - HELP me before I become another BMW loser !!...............
Bumped car in July last year - fairly minor, but had new rad, water pump took a hit -had new, plus other bits at the front.

Cars makes a noise over 3500 revs - in any gear and neutral stood still.

Insurance co and Lexus Leeds can not sort it, and I think they are avoiding my calls.

We have all tried bleeding it ( I tried it - didn't work - great photo though front 2 foot in air - I'll post it when its sorted).

Ins co bled the system, with some gizmo that actually forced coolant through, rather than just jacking it 2feet at the front to bleed.

This worked for four miles, now its as bad as ever, It has a similar sound to NOS on Need for Speed Underground. But unfortunately to me sounds terrible.

Lexus Leeds clamped the top heater hose and the noise went (although only tested when stationery)

So we at least know its coolant now -- oh thats after a new cat and a new alternator - thank g at the ins co expense.

Any ideas - or things to try/test ????????

←

if it sounds like air in the coolant, and you def have no leaks, then the water pump impeller could be slightly out of tolerance causing aeriation ( bestway to decribe is like a spinning ships propellor under water causes airbubbles due to friction heating the immediate water around the propellor) the waterpump impellor blade angle is carefully designed to prevent this, but it is possible that yours may be slightly out. However it is a lot of hassle to replace it just to see if it cures it.

←

Thanks - whilst I can put up with it and have for 10 months, there would be little chance to sell it with the noise, unless they trest drive it without going over 3500 revs. which lets face it is fairly unlikely.

The water pump was replaced as part of the insurance repair so may be they will change it foc.

crazylex · February 7, 2006

Finally got this sorted.

Even though Lexus Leeds said it need a new heater matrix, infact it just needed flushing.

I bought a brand new heater matrix of eBay, but never actually fitted it.

I just took the pipes of the existing matrix and jammed a hose in and flushed it in the opposite direction to the normal flow.

Theres no noise now.

Which I am delighted about.

What p******s me of is why the F*** did the insurers or Lexus Leeds not do this . Especially when one of said some debris might have got stuck in it. And they had it at least four times to try and solve the noise, even after they changed the alternator and the a cat o pre cat (not sure what they changed - except it cost the ins co £800

Anyway - if any one wants a brand new heater matrix - I have one going cheap.

No doubt someone might in the next few years.

vinokirk · February 8, 2006

I have a similar problem, dont know if its a normal noise?! If im stood still in neutral and i just tap the accelerator i get a seemingly bubbling noise comming from behind the dash.

Anyone know what this it??

crazylex · February 8, 2006

I have a similar problem, dont know if its a normal noise?! If im stood still in neutral and i just tap the accelerator i get a seemingly bubbling noise comming from behind the dash.
Anyone know what this it??

It has air in the pipes.

Theres some threads on here that explain how to get it out.

Give me a minute.

heres one link