Author Topic: repairing coolant leak 2.5L V6  (Read 4167 times)

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cc

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repairing coolant leak 2.5L V6
« on: February 19, 2017, 10:55:44 AM »
After putting the alternator back in, im onto the coolant leak while waiting for the obd interface to arrive. As Baz pointed out, water doesnt flow up! and the pink deposits left after the weeping coolant has dried, mark the highest point of the leak.
Which is the housing on top of the water pump that the return coolant pipe joins into.
See pic. The totally alfa web site in the UK has the factory manual in pdf for the engine that shows the exploded view.
Does anyone know if an annular gasket is used to seal the pipe into the housing or just sealant? Would like to R & R the housing gaskets? without removing the timing belt..
ohh no! nothing that simple! Has anyone experience with this?
« Last Edit: February 19, 2017, 11:10:41 AM by cc »

cc

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Re: repairing coolant leak 2.5L V6
« Reply #1 on: February 20, 2017, 08:08:01 PM »
wow! have received the UK quote for 10 O rings needed. Without vat or freight; $16.16.Not listed as a genuine part; maker is 'other'.

 Local Brisbane supplier who supplies genuine parts $128. Phew. Looked up the price in eper and the genuine part price there is much closer to the alfaworkshop listing. Will source from the UK.... shipping is GBP 9.50 AUD $15.41

Will have to remove the thermostat housing, held by 2 bolts, to access the O ring locations. Which means disturbing each cylinder heads connection between the cylinder head and the thermostat housing.
Spoke to an experienced alfa mechanic re whether to use a sealant with the new O rings. He advised its not necessary but will do no harm. He uses vaseline to help the fitting.

Have added pics of the coolant pipe connections on the thermostat side. Note white sealant used... dont know if its  factory. Am using a long allen key to point to each connection.
« Last Edit: February 22, 2017, 01:05:09 AM by cc »

cc

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Re: repairing coolant leak 2.5L V6
« Reply #2 on: February 25, 2017, 02:30:25 PM »
Have ordered today the required O rings, 8 in total, in 3 different sizes! Also the sprocket with new key that sits behind the harmonic balancer and drives the timing belt. The current one has a chip out of it (the sprocket). Also a new nut to hold it all on the end of the crankshaft. Came to $109.78. Ex UK from the alfaworkshop. When i put the H balancer back on last time, without torqueing it up to the required massive torque. It went on slightly eccentrically. Have read? dont recall where, some garages will use a rattle gun to torque it on. I had to hire a r gun to take it off.

cc

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Re: repairing coolant leak 2.5L V6
« Reply #3 on: March 09, 2017, 10:20:52 AM »
Ordered last monday arrived after 9 days.. Some pics of parts. The key is a almost perfect in the sprocket key way. The key is shared with the harmonic balancer. Big range of  o rings sizes. Ordered the ring sizes on advice from a local alfa mechanic.

cc

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Re: repairing coolant leak 2.5L V6
« Reply #4 on: March 09, 2017, 10:22:53 AM »
more pics. O ring inside diameters and thickness given. Note jesus nut comes with a rolled flange on the end of the thread. Jesus nut is a technical  term used for a nut who's job is to hold the entire engine together.: ).Also for holding a helicopters rotor blades on.
« Last Edit: March 09, 2017, 10:26:45 AM by cc »

bazzbazz

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Re: repairing coolant leak 2.5L V6
« Reply #5 on: March 09, 2017, 02:51:08 PM »
And WHY is it called a "Jesus Nut"?

Because when it comes off everyone screams "OH JESUS!" 

 ;D
ON THE SPOT ALFA
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2004 Alfa 156 2.0 JTS Sportwagon (Patty)

allbj

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Re: repairing coolant leak 2.5L V6
« Reply #6 on: June 26, 2021, 06:01:30 AM »
more pics. O ring inside diameters and thickness given. Note jesus nut comes with a rolled flange on the end of the thread. Jesus nut is a technical  term used for a nut who's job is to hold the entire engine together.: ).Also for holding a helicopters rotor blades on.

Hi CC,

A bit of an old topic but will give it a go.

I am changing the o-rings for the coolant system on my 156 3,2 GTA.

But I cannot understand the size of the smallest o-rings on you picture, they are 20x2,5 mm.
however the inner diameter of the groove on the stud where they should be mouned is 26 mm.

I believe this would stress the o-ring.

It is correct thogh, according to the alfa pictures and list I can find.

Do you remember if you found this strange?

Best Regards Allan

cc

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Re: repairing coolant leak 2.5L V6
« Reply #7 on: July 22, 2021, 05:10:36 PM »
Hi Allan
Im afraid the red 156 is still in the garage & im getting around in the blue 156.
So cant comment on the O rings.
Instead have put a spider back on the road (with help) so will get back on this topic in 12 months
cheers CC