Technical Problems after changing head gasket

[rblack75]

I have a 52 REG 1.2 8v Punto and about a month ago it overheated in slow moving traffic. I noticed it as smoke started coming from the engine.

I managed to get it to a garage who said it was the head gasket and quoted me £475 part and labour. I could not afford this so took it home and decided to do it myself with the help of my brother who recently change a HG on a Peugeot 405.

We git the Haynes manual out and did it by the book. I had the head skimmed and we bought a new HG set with new bolts. Fitted using the recommended toque etc.

We also replaced the water pump and thermostat

We bleed the cooling system as described in the manual

However the car is still running rougth and sometimes missfires as you drive it causing loss of power. It also seems to be getting rather hot and there is a weird bubbling sound coming from the heater matrix.

I guess there is still an air lock so tried bleeding again using the guide on the forum but still have no luck. There is still steam coming out of the exhaust but the water level still stays around the same.

Trouble is I dont want to run it too long in case I blow the HG

any ideas?

also would an airlock after the HG change cause the car to run rough?

 

[fiat brava jtd elx 105]

how long hav u let it run for cause mine had water residue left in the exhaust after the head gasket blew and just a thought tht i tried. when the engine is cold take the bleed screw out the top of the radiator and pipe for internal heater and pour water in top of the raditors bleed screw until u here a bubbling noise or water pours out this should force any air out if its an airlock.

 

[sixpotman]

Did you also fit a new cambelt and make sure that
the timing is set right. Plus how did you ensure the
cambelt was at the correct tension.

John

 

[rblack75]

The car has only done about 50,000 miles and I had the cambelt replaced about a year ago. The belt is in very good condition.

We checked the timing by lining up the marks on the cam and crank with mark on the engine casing. we tested tension as described in the haynes manual. i.e grip longest run between finger and thumb and should only be able to twist by 90 degrees. First time we got it to tight which caused squeeking so readjusted .

 

[rblack75]

When I bleed the cooling system took the bleed srew out and poured water in untill I could see it pouring our of the hole. I then continued to pour water in while i squeezed the tube going onto the hater matrix to try and make sure I got the air out. I then did up valve as water was still coming out.

Unfortunately still a bubbling coming from inside the car when you start

 

[sixpotman]

Both bleed screws? on radiator and heater pipe

John

 

[rblack75]

yep both the bleed screws, made sure plenty of water was pouring out of both of them then closed the back one. Next I squeezed the tubes getting water out the Rad bleed screw untill the water level got down to the Max level. I then closed the Rad bleed screw

 

[tinytim]

most likely cause of rough running is damage to the lambda sensor due to the HG failure; fairly easy to replace but make sure you get a high quality new one; puzzled by the bubbling sound tho'; just a thought but when you bled the cooling system did you have the heater valve set to the "hot" position so that water was circulating through the heater matrix?

 

[rblack75]

Just tried bleeding the system again with the heater dial set round to its hottest

Still get a bubbling sound when I start the car up, it eventually dies down and goes away but its not right

 

[HgtBill]

When are you bleeding it? I find running it up to temp and then bleeding it helps get the air out better.

 

[rblack75]

I am Bleeding it Cold as all guides and manuals suggest

 

[DaveMcT]

I had this on an old Ford. None of the book methods worked. Eventually we bled it with the engine running squeezing hoses etc. but be careful to not let it get too hot.

 

[testacorsa]

New on this forum, but hope i can help

Air in the cooling system can be very very bad, and must come out. I had an 8 valve for about a month, that i bought to make a bit of fast dough.
I also changed the HG and had the exact same bubble noises that you discribe.

I got the air out when the engine was hot, by parking the car on a steap hill. If you park with the front at the higest point, the air will get to the radiator (rev it a bit and leave the cap off, and use the bleeder screw)
If this didn´t do the trick, turn the car around, with the back at the highest point - this will make the air travel to the heater matrix bleeder screw (ish). The heater must be set on the hottest setting.

I´m surpriced that haynes suggest bleeding the car cold!
Air could be trapped by the thermostat, because it´s only open when the car is hot. Furthermore the cirkulartion is at a minimun with the thermostat closed.

If your have an airbubble trapped by the headgasket, it can create a hot spot, and burn your HG once again - so bleeding the air is pretty crutial.

Best of luck!!!

 

[HgtBill]

Haynes manuals are poor, there good for torque settings and putting your tea on.

 

[rblack75]

Thanks for the advise

I will try bleeding the car on the hill a little further down my road tonight and then see what happens!