156 jts water on 3 spark plugs

Started by MattyG, June 23, 2018, 01:13:12 PM

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MattyG

Hi crew
First foray into Alfa repairs. Timing belt job on my daughters 156 Alfa took the coils out and it seems to have water around the first 3 spark plugs. Could this be a head gasket starting to fail? Seems strange. 


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MattyG




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johnl

#2
I've seen no actual water in my plug wells (TS engine), but there is evidence that there has been at some stage, i.e. rust deposits on the metal parts of two of the original spark plugs, and still there on the metal parts of the tubular HT connectors that attach to them (I cleaned them up, but there are still rust stains on the plated metal). There is no obvious path through which leaking coolant could end up in the plug wells (oil yes, but not coolant), so it's a bit strange.

Speculating, if the engine were ever hosed off with the plastic cover removed, then it would be very easy for water to get into the plug wells, and it could take a while to evaporate out...

Your plugs look very black. I suspect your AFR is very rich. Perhaps the O2 sensors? Maybe that, or do you do lots of short trips?

Regards,
John.

MattyG

Thanks John. We have only picked it up and driven it 6 hours home. I gave it a bit of a degrease with ct14 spray and a light hose but had the cover on and it all look like it hadn't been cleaned for a while.
I am think my any residual water from previous owner would have evaporated on a 6 hour trip.
156 jTS has coils on top of the plugs. With 3 rubber rings to seal it. Bit strange


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MattyG

It a bit of a challenge to get the variator off ended up with the cam shaft out in the vice. Got it off.


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Citroënbender

You have the variator socket, surely?

I'm sure the water is from pressure cleaning or protracted driving in really foul weather, antifreeze would have looked different.

Plugs may tell you of a failed thermostat either now or recently.

bazzbazz

Quote from: johnl on June 23, 2018, 02:34:31 PM
Speculating, if the engine were ever hosed off with the plastic cover removed, then it would be very easy for water to get into the plug wells, and it could take a while to evaporate out...

Give the man a cigar!

This is a common problem with 156/147 4 cylinder engines, when washing the engine bay water gets in under the plastic cover and then works its way past the coils into the spark plug wells. Once down there it gets trapped by the rubber seals on the coil stalk.

I recommend people to wash their engine bays and keep it clean just like the rest of the car, but to take the plastic engine cover off and cover the top of the engine area with a plastic tarp/plastic sheet to avoid water ingress.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

MattyG

Yes I have the Variator. Socket I needed the timber jaw vice and a whole lot of leverage to get it off. There was no thread lock on it but a believe that is a good idea. Anyone have the torque settings to do it up again?

Relieved about the water. What is the story with diagnosis of thermostat how do I test that?

Also how do I test O2 sensors and MAF? I'll clean the maf with the proper stuff tomorrow but is it just an OBD2 setup? Cheers Matt


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Citroënbender

#8
Thermostat, if it doesn't reach normal smartly and stay firmly there under nearly any condition, it's cactus.

You really need runtime data (graphs are ideal) with the oxy sensors to see how they are tracking, spot readings can be deceptive.

As to the MAF, maybe I've been lucky (?) but every time I've changed it there's no difference other than being £120-odd lighter in the pocket.

eLearn is a handy reference, if you can secure a disc or torrent for the model.

MattyG

Thanks for the tips. I'll look into elearn

I haven't been able to track down the Timing belt tensioner tool? I have the Balance belt one but not the other one. Any tips on how to set the timing tension without that tool? Cheers Matt


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Citroënbender

I've usually gently pried the tensioner when tightening the locking bolt, aiming for slightly over (tighter than) the match marks. That way, after the eight test revolutions if it needs backing off slightly it is just a matter of careful loosening of the centre bolt to slip it a fraction.