My Sei 1.1 sporting has recently had a recon head, gaskets and thermostat fitted. All seemed good but I've noticed I'm losing a small amount of water from the header tank when I check it weekly. Yesterday after topping up I left the car to run up to temp and for the fan to cut in with the cap off. As the car got warmer the coolant level started raising and dropping getting increasing in level difference as the car got hotter. I allowed this to carry on to the point that the coolant raised so high that it started overflowing from the tank. One more point to add is that the thinner pipe which connects to the top of the header tank got quite a bit hotter than the thicker pipes on the radiator/engine.
What could be causing this? Is there a problem with the new head, water pump, rad???
Thanks very much in advance for any helpful comments

the auto needs the cap on it increases the coolant boiling point you need to repeat the test with the cap on and locate the leak

I would guess that the water loss is the cause of the effect of popping the gasket.

Have you bled the cooling system.

Cheers

D

The water level will rise with temp as water expands when it heats up. The cap keeps the pressure up in the system so the water doesn't expand as much

Thanks for responses, the system has been bleed. Will top back up to the correct level and try to locate where the water is leaking from. Just a bit paranoid after having the initial head failure that lead to the work being carried out.

The head failure may be the effect of the leak...

Cheers

D

Ok thanks, if the head or gasket have gone again it may be time to scrap the Sei. :-( Will have to wait and see how it goes. Fingers crossed.

Ok thanks

Noo don't scrap it! Head gaskets are easy to change, will cost you about £40 and an afternoon's work If you're not sure how to do it, look online for a Haynes manual for your car or for some other tutorial of which I'm sure there are many

Did you change the pump when you did the head?

Cheers

D

if the pump is damaged the little pipe will be hotter than the other pipes but the test needs to be repeated with the cap on, the little pipe gets hot first even if the pump is ok

To summarise a little:

Head Gaskets generally go for a reason -- if you don't fix the reason, they'll go again.
Usual reason they go are, faulty thermostat, faulty water pump, radiator fan not coming on, water leaks.

The most common places for a leak which is otherwise invisible are a leak from the water rail (the pipe which runs along the front of the engine), a leak from the water rail to water pump O ring seal, a leak from the water pump itself. Often these can only be seen if you run the engine up to temperature and (engine running) crawl under the car.

A compression test would show if the HG has failed again. Cheap testers on eBay.

Scrapping a car because the head gasket has gone is rather like scrapping it because the ash tray is full.

I agree with Fingers completely. No need to panic. I have had issues with my cooling system loosing for years and the last thing I changed was the water rail o ring. What made it difficult to detect was the type of coolant I used. The one I used first used to evaporate leaving no sign of a leak whereas when I used an oily type it left a pool on the floor so I could trace it... The manual suggests its a walk in the park to change the o ring..yeah right!! The heat shield on mine prevents access so its strip the front end to get at it! Battled for ages until I resigned myself to stripping everything. Would have done the job in an hour if I had started out with removing the radiator first! Remove the arch covers, drivers side headlight, front bumper, radiator, heat shield and then the water rail is easy to remove. The o ring was as brittle as bakelite as was the one on the coil pack holder. How nice it is to finally see the coolant level stay constant week after week!!

Thanks again for the fantastic responses, the water pump wasn't changed so think it maybe worth changing that anyway. Will order one and have a go this wk end using the guide on here.

The fan is kicking in as it should, might aswell change the o ring aswell while I'm at it. Thanks

ma876 said:

The fan is kicking in as it should, might aswell change the o ring aswell while I'm at it. Thanks

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it's around 16-18 pound for the new pipe which comes with the new Oring. If yours doesn't look too good, is well worth changing!

Ming

ycming said:

it's around 16-18 pound for the new pipe which comes with the new Oring. If yours doesn't look too good, is well worth changing!

Ming

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Very good advice! Forgot to mention the hour it took to recondition the water rail which had corroded. I brazed it up and machined it back to original form..spares are just too pricey here and I make a plan wherever I can! Just amazing how many of the rubber bits fail...go brittle or just tear..perhaps its something in the air here?

Frosty1961 said:

Very good advice! Forgot to mention the hour it took to recondition the water rail which had corroded. I brazed it up and machined it back to original form..spares are just too pricey here and I make a plan wherever I can! Just amazing how many of the rubber bits fail...go brittle or just tear..perhaps its something in the air here?

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I think Fiat brought out a new design for the O ring which consists of a double lip!

But yeah, with old cars ,rubber tends to fail

Ming

ycming said:

I think Fiat brought out a new design for the O ring which consists of a double lip!

But yeah, with old cars ,rubber tends to fail

Ming

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The o ring I got from fiat recently was a plain round one..but looking at the parts cat it looks as if there are two different designs? One has a flange type arrangement and the other is an o ring sitting in a groove of the pipe like mine...

As an aside the rubber covers on the headlight bulbs failed within a year.. Glued up all the splits and they are still fine 12 years later! Weird!

Buy the pipe from Mick at Eurocarcare.net and it comes with a fancy double seal o-ring, much better than oem item.

this one.
http://www.eurocarcare.net/hose-pipes/ecc55217638-coolant-pipe.html