its frothy man!

its frothy man!

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dickymint

Original Poster:

24,381 posts

259 months

Wednesday 5th March 2003
quotequote all
2 whole months of trouble free wedging.Too good to be true eh! You all know the feeling-Just before something goes bang it feels like its never been going so well!(that horrible feeling of optomism

Temp gauge starting to creep up so thought it time to top up the coolant

Got pure white froth in swan kneck and expansion tank.
Q. is this likely to be terminal or cos its not "dirty froth" could it just be air entering system?

GreenV8S

30,208 posts

285 months

Wednesday 5th March 2003
quotequote all

2 whole months of trouble free wedging.Too good to be true eh! You all know the feeling-Just before something goes bang it feels like its never been going so well!(that horrible feeling of optomism

Temp gauge starting to creep up so thought it time to top up the coolant

Got pure white froth in swan kneck and expansion tank.
Q. is this likely to be terminal or cos its not "dirty froth" could it just be air entering system?


If it has got *really* low the water pump turns into a glorified whisk and produces a nice froth. Has it got very low? If so, the obvious question is why? Time to top up, bleed thoroughly, watch the temp gauge like a hawk and keep a care eye on the levels over the next few trips.

dickymint

Original Poster:

24,381 posts

259 months

Wednesday 5th March 2003
quotequote all
it seemed to be full, could just squeeze in about a pint. But maybe a massive air lock. Time to fit a bleed valve maybe.

Paceracing

729 posts

267 months

Wednesday 5th March 2003
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You might want to get a cylinder leakage test done, it's fairly cheap and pretty quick to do.
You may have a head gasket problem where the gasket has blown between the cylinder and the water jacket. This would pressurise and airate the water in the cooling system and may cause the frothing you mentioned.

Jas.

dickymint

Original Poster:

24,381 posts

259 months

Thursday 6th March 2003
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Fair enough.But would a leak of this nature give "discoloured froth"?
How is a cylinder leakage test done (is this a leakdown test)?

Nickleby4

9 posts

254 months

Tuesday 18th March 2003
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Frothy water - hmm. The obvious two are weird antifreeze, and a lack of coolent (not uncommon on TVR's - let's face it) and head gasket.

If it's head gasket it will diagnose itself eventually. However you do need to be sure that the oil is not also frothy - that would get expensive quickly, so have a look. If it is don't drive it like it!! The root cause in this case would be that the gasket is leaking between oil and water galleries, and you will likely fid that there is flow both ways (from oil to water running, and from water to oil not running).

The other head gasket failure would be from compression are to waterway. You get the froth as the pressurised air / fuel is forced into the coolent, and you lose some (little) coolent as the water flows back with the engine off. Eventually you will get a fairly serious misfire, and rapid overheat from this. Earlier on you may find that you get a poor start up &/or rapid pressurisation of the cooling system. The start is because one of the cylinders is 1/2 full of water so the engine goes over until the piston has to compress the water and stops. Usually after a couple of goes it forces the water into the sump and cranks normally, though this can bend rods in extreme cases. I have heard this described as a lumpy start!!

Has the car overheated at any stage? That is the most common cause of head gasket failure. typically the damage is down during one good overheat, but the symptoms do not start to show for a couple of months...

Bon courage.

Pettsie

354 posts

258 months

Wednesday 19th March 2003
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If its a white frothy cream then its probably a gasket