V8S expansion noises?

[Moakesie]

I'm getting expansion noises, like hot water into cold vessel or metal expansion when car has been running for 20-30 minutes. Not using/losing coolant, heater working fine, nothing appears loose underneath like the exhaust system, me and TVR mechanic really confused! Car carries on working fine, no issues, yours confused!

[Oldred_V8S]

At the risk of opening a can of worms; do you have the pressure cap on the swirlpot or the expansion tank? It should be on the swirlpot? Anyone that tells you otherwise is just plain wrong!

I have a technical bulletin from TVR that backs up the above. Which, when you think about it is sensible, you don't want a plastic expansion tank under pressure.

[Moakesie]

Thanks for the response. Yes, the pressure cap is on the swirlpot, but thanks for getting back. I've also heard of TVR's having them the other way around, but as you say it really doesn't make sense.

[phillpot]

I'd start by draining, flushing and refilling complete system with fresh anti-freeze mix. Bleed off air, run and test.

But I'm not a TVR Mechanic

[Moakesie]

thanks, that could well be a great and reletively simple starting point.

[Bobhon]

The little valve on the pressure cap on the swirlpot was stuck open on mine. So it was constantly pushing water into and drawing it out of the expansion tank.
Might be worth having a look at it. If you squeeze the hose above the thermostat housing and get the swishing noise when the engine's cold then it may well be your issue.

[v8s4me]

Moakesie said:

I'm getting expansion noises, like hot water into cold vessel or metal expansion when car has been running for 20-30 minutes. Not using/losing coolant, heater working fine, nothing appears loose underneath like the exhaust system, me and TVR mechanic really confused! Car carries on working fine, no issues, yours confused!

Unless you're desperate for something to do and/or spend money, ignore it.

If you really want to do something, change the cap as mentioned above.

[Moakesie]

Thanks guys, great advise, I think i'll start with flushing the system and putting in new antifreeze, replacing the caps and thermostat and see how it goes. I do agree, we can spend our time listening for every grumble and groan instead of simply enjoying the drive!!