Possible head gasket woes....or worse
Possible head gasket woes....or worse
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TVR_nut_2008

Original Poster:

22 posts

216 months

Tuesday 30th December 2008
quotequote all
After a bit of advice chaps,

Been out today in the Chim, seemed to be running fine. Waiting at a red light and see some steam coming out of the driver side bonnet vent, pull over as soon as possible and there's a gurgling sound. Pop open the bonnet and coolant is escaping from expansion tank and the cap isn't on properly. Not much coolant appears to have escaped and the car didn't overheat (no higher than 85 assuming it's working properly). There didn't appear to be any mayo on the oil cap or dipstick, but there was a tiny amount of brown scum on the expansion tank cap. Once home, there's no fluids under the car at all.

The car does lose a little water (0.5l tops over 1000 miles) and I had just topped it up yesterday, so optimistically it could have been me not screwing the cap back on properly.

However realistically I'm worried about the head gasket or worse (slipped liners etc). Are there any simple tests I can do to determine what's going on before getting someone to look at it?

Any help on this and I'd be most grateful.

Thanks

GreenV8S

31,027 posts

315 months

Tuesday 30th December 2008
quotequote all
Everything you've described so far looks like a very simple cooling system leak at the cap, and I wouldn't be bothered about looking for more serious trouble.

You can pressure test the cooling system to see where the leak is. If the HG has gone between the water ways and the chamber then you could expect to see more steam than usual from the exhaust plus combustion gases in the coolant. This would usually be visible as froth blown out of the header tank if you blip the throttle with the cap off, but it's also possible to test for trace amounts of combustion products in the coolant using a 'block tester' (aka sniffer). If the HG has gone between the water and oil then you would also see emulsion in the water, and emulsion in the oil. However, you will get emulsion in the oil under some conditions anyway so emulsion in the water is the main thing to look for.

f@-pots

204 posts

234 months

Tuesday 30th December 2008
quotequote all
Hi, Like Green says, it sounds as simple as 'not putting the cap on correctly'. As you know the system needs to be pressurised in order for the fluid not to boil,if you take away the pressure then boil it will! Top it up, bung the cap back on and go for a spin, that'll tell you if all is OK.

Best of luck , Nick......................

WOO5IE

967 posts

228 months

Tuesday 30th December 2008
quotequote all
Sounds exactly what you have described as a cap not fitted properly.

I wouldnt worry unless it happens again which is unlikely or you get some more symptoms
With regards to water loss you say that you need .5L every 1000 miles. Are you sure that it needs this. Are you filling the expansion tank up to the brim every time. If you are then all cars will find their own level and is normally about 2-3 inches from the bottom of the tank. The car will chuck out any water it doesnt need so all you may be doing is replacing this water every time.. The longer you own the car you will get to know its 'LEVEL' they are all slightly different..

You could just be watering down the antifreeze level each time unnecessarily

You dont need to be paranoid about this!!


Trev

spend

12,581 posts

282 months

Tuesday 30th December 2008
quotequote all
TVR_nut_2008 said:
but there was a tiny amount of brown scum on the expansion tank cap.
I hope its not one of these snake-oil additives to cure-all? wink

TVR_nut_2008

Original Poster:

22 posts

216 months

Tuesday 30th December 2008
quotequote all
Thanks for the responses so far, may be I've been a bit over paranoid, but that's what Chim ownership has done to me!

There is no more smoke/steam in the exhaust fumes than normal (normal being what you'd expect on any healthy car).

Topping up the coolant - I'd always topped up the expansion tank to halfway, although I will take on board your advice about this and see how things go.

Snake oil cure-all!? Nothing I've put in there, although it is possible the previous owner stuck some in, as he was aware of the minor water 'loss', if indeed that is what it is as above.

Service booked at TopCats for the middle of next month, so hopefully all will become a bit clearer then, although I want to be sure I can get there as it's a 100 mile drive. Sadly my nameless local let me down on the pre-purchase inspection I had done with them hence why I'm travelling, couldn't detect a slipping clutch, which was easy enough for the previous owner to drive around, but pretty obvious to me once I started driving the car. But hey, there's nothing like a bit of expense to make one learn a lesson for next time!

Thanks again for the responses, will post how things go for completeness.


daz the plumber

14,997 posts

262 months

Tuesday 30th December 2008
quotequote all
can any one explain why there are two coolent points (vessels) and what is the procedure to top up .

slideways

4,101 posts

252 months

Tuesday 30th December 2008
quotequote all
daz the plumber said:
can any one explain why there are two coolent points (vessels) and what is the procedure to top up .
one is a swirl pot the other an expansion tank, the swirl pot has a cap to be able to bleed the air out if there is no air in the system top up the expansion tank as normal

fatboychim

979 posts

282 months

Tuesday 30th December 2008
quotequote all
WOO5IE said:
Sounds exactly what you have described as a cap not fitted properly.

I wouldnt worry unless it happens again which is unlikely or you get some more symptoms
With regards to water loss you say that you need .5L every 1000 miles. Are you sure that it needs this. Are you filling the expansion tank up to the brim every time. If you are then all cars will find their own level and is normally about 2-3 inches from the bottom of the tank. The car will chuck out any water it doesnt need so all you may be doing is replacing this water every time.. The longer you own the car you will get to know its 'LEVEL' they are all slightly different..

You could just be watering down the antifreeze level each time unnecessarily

You dont need to be paranoid about this!!


Trev
Just to second what WOO5IE said, the car will level itself out at somewhere around the mid-point of the header tank, if you keep topping it up it will keep dumping it. Obviously you are right to keep a sharp eye on it but let it settle for a bit and see if it carries on emptying itself beyond halfway, then you know you actually have a problem. If, when you remove the screwcap there is a little air in the swirlpot, squeeze the top hose until the coolant fills the tank completely then refit the cap. Good luck with it.
PS. I often use a bit of copperslip on the swirlpot and the header tank caps to ease their release, this does cause a bit of brown gunk to form around and under the caps.



Edited by fatboychim on Tuesday 30th December 21:31

daz the plumber

14,997 posts

262 months

Tuesday 30th December 2008
quotequote all
so you fill the lower one with the blue screw top and bleed from the brass one which is a b.....d to un screw.

steviegasgas

417 posts

216 months

Tuesday 30th December 2008
quotequote all
I just had radiator out, according to bible you undo bleed screw on rad, undo blue cap off bottom expansion pot, then fill up top swirl pot with coolant, i couldnt undo brass screw, so undid hose instead, fill up till air stops coming out rad, then fill to top of top pot, then fill lower expansion till two inches from top, run it till fans come on, let it cool down till cold, check coolant level in bottom pot, the level varies from car to car seemingly, does that make sense? Hope so cos it worked for me!!

f@-pots

204 posts

234 months

Wednesday 31st December 2008
quotequote all
thumbupYes Daz thats it exactly.I'm sure there was a thread not so long ago on this subject,just to echo what someone said then, it's got to be nigh on impossible to totally bleed the system when you've got the stat housing to swirl pot hose sticking its arse so far up in the air way above the swirl pot filling point.I suppose you could try squeezing the hose with one hand , filling with the other hand and for those from the planet ZOG turn the bleed screw with the other!! laughYou would then, on releasing the hose , get the extra fluid needed from the expansion tank. Thats what I did anyway and I've not had any problems 'to date' ! (shouldn't have said that should I) ?nono

Best of luck , Nick..................

TVR_nut_2008

Original Poster:

22 posts

216 months

Thursday 1st January 2009
quotequote all
Quick update.

Took the Chim out to see what would happen. After the first mile or so before things got too hot, checked the water in the expansion tank and it didn't seem to have dropped at all plus there were no signs of mayo/emulsion. With this my confidence increased a notch so I took it on 10 mile trip on the fantastically quiet A12. Everything seemed fine, heater working as normal, tempurature nice and low and no steam in the exhaust. Just waiting for it to cool down now before I check everything again, but touch wood it looks like I'm in the clear. I will therefore in future make sure caps are screwed back on properly subsequent to me taking them off, this episode has taken years off my life! I don't think the missus will ever let me forget this given the amount of times I've told her to make sure she screws caps back on when she's checking her car!

Thanks for the responses and all the best for 2009.

spend

12,581 posts

282 months

Thursday 1st January 2009
quotequote all
f@-pots said:
thumbupYes Daz thats it exactly.I'm sure there was a thread not so long ago on this subject,just to echo what someone said then, it's got to be nigh on impossible to totally bleed the system when you've got the stat housing to swirl pot hose sticking its arse so far up in the air way above the swirl pot filling point.I suppose you could try squeezing the hose with one hand , filling with the other hand and for those from the planet ZOG turn the bleed screw with the other!! laughYou would then, on releasing the hose , get the extra fluid needed from the expansion tank. Thats what I did anyway and I've not had any problems 'to date' ! (shouldn't have said that should I) ?nono

Best of luck , Nick..................
Those small blanked off throttle heater hoses can come in very handy if you are cunning when refilling the system wink