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Drunk Head gasket going out? coolant pressure

Hi,
I have a 166 JTDm 20V 2.4.
As it's the same engine as the 156's - Not really, it's a mix between 156 block/accesories/turbo and 159's cylinder head!, I'm asking here
I hope some experienced members can throw some light on this!

Small history: since I bought the car it had small coolant leaks on the hoses, seemed just loosen clips, but eventually I noticed too much pressure on the expansion tank.
On arrival after a long trip (300miles, having a look to the temps every 2 minutes) I stopped at a gas station and took the oportunity to check the coolant... and had almost disappeared! It only had 1inch of depth! Topped it up and that day I drove with the cap slightly loosen to prevent pressure built-up.
Once at home, I added a leak stop additive, and it certainly almost fixed the hoses leaks.
Happy with it, I used the car for few weeks without issues.
But only once, after being parked the whole weekend, tried to start and didn't turn!
I thought, dead battery? Nope, the lights were strong even when I turned the starter on. What the ****?
After several tries it finally started, shaking with very unstable idle and throwing some white smoke.
Could it be just condensation...and the swirl flaps full of soot..and a faulty starter?...hehehe of course not!

Once in the highway, I noticed that I was leaving a giant white cloud trail, totally blocking visibility behind me.
Released the gas and drove very calm until the next exit.
In 2-3 minutes it stopped making smoke, and has never done that again, 3 months has passed since then.
But the pressure is still happening, on cold mornings I remove the coolant cap and it releases some pressure.
After a half hour run, if I turn off the engine and go to the engine bay, I clearly hear the coolant cap slowly releasing the excess pressure built inside.
No oil on water nor reverse. Need to refill 1/3 of the coolant tank once a month or so.
The EGR is blocked at the manifold, the egr cooler could still pressurize the coolant if cracked.
But it can't fill a piston with coolant!
So I was almost convinced of a failing HG, it has to be an extremely small crack on the gasket, I can't think on other source for this problem .

With the cap off the water doesn't "boil", only when revving hard some micro bubbles appear, they look like a slight foam.

But, wait a moment!
Suddenly I remembered that the coolant passes thorough the inlet manifold on 16/20v jtd engines!
Could the manifold gasket break and allow boost pressure to leak into the coolant, and then, when the engine is stopped, leak coolant back into the manifold, thus hydro-locking the engine like it happened before?
Or definitely head gasket problem ?
Sorry for the half Bible! I hope you like reading!
Cheers and sorry for my (probably) awful English


Last edited by DavidAlfa166; 14-12-16 at 13:28.
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Try a sniff test kit on the reservoir.
https://www.amazon.co.uk/Testers-col...+gasket+tester
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This certainly sounds like a head gasket. My 1.1 punto had exactly the same symptoms way back in the day when its head gasket went. Only difference was the coolant resevoir did boil over when left idling.
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My comment definitely won't help you out, but I just felt like I needed to say it : Your car is gorgeous!!!
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Quote:
Originally Posted by ransoman View Post
This certainly sounds like a head gasket. My 1.1 punto had exactly the same symptoms way back in the day when its head gasket went. Only difference was the coolant resevoir did boil over when left idling.

As did my TS .. couldn't see a leak but kept losing coolant. It was being pressurised by a blow in the HG and eventually did good job of keeping one piston clean ... there was a puddle in that bore!

Because it was coming into winter didn't think anything of the condensation from the exhaust as the car was often left out overnight but now realise it wasn't normal!
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(Post Link) post #6 of 28 Old 10-08-16 Thread Starter
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Quote:
Originally Posted by dgmayhead View Post
Try a sniff test kit on the reservoir.
https://www.amazon.co.uk/Testers-col...+gasket+tester
Wouldn't it be cheaper a single test at a local workshop instead of buying the whole kit? I don't have plans to foock up the gasket from time to time

Quote:
Originally Posted by tishobg View Post
My comment definitely won't help you out, but I just felt like I needed to say it : Your car is gorgeous!!!
Thanks! Love it too! Except that damn gasket which I hate so much now! I they could suffer...




I'm thinking on repairing it myself. the injectors are clean and should come out easily. the rest is hours and more hours of a hell of dismounting, but not too complex.
I can borrow cam locking tools, torque wrench and goniometer for the critical steps.

The torque procedure is well described on eLearn.
Will give a pass with the screw tap to ensure clean threads, resurface the head just in case, although it shouldn't be bad, but I can do it for just 20-30 bucks, so it worths it.
Some say to not lube the head screws, other say to apply a very thin layer just to make it easier and safer. So, what to do??

Also will put new valve seals, camshaft seal, remove swirl flaps, repair and resurface the exhaust manifold (broken stud caused by heat warping), change belt kit +pump, new glowplugs, clean the turbo VNT (I think it's sticking a bit)...Also I know I'll have to put new injector washes and screws.
Basically I'll be very busy for some days, check up the coffee price because it's going to grow up



Any help on this will be very appreciated, never worked the head before, althought I've done engine mounts, turbos, aux belt and pulleys on my ex-156.
I've been watching tons of videos and doesn't seem that hard, the rule is to keep and eye on what you're doing and don't mess anything up.

I made a list of parts, including oil+filter and coolant, and it's going to be round 500 euro (~ £430). Not too much considering the result, the engine will be done for running for a lot of miles without any more maintenance than oil and filters

Regards!
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Sniff test doesn't always work.

Fill your coolant to the brim with the cap off. Watch the engine warm up and keep and eye on the coolant. You will start to see bubble and more frequent as the car warms up.. - Head gasket for sure.

Other signs, cars heating may be cooler then normal. Coffee colour in the oil (look at dip stick). Look at the oil filler car, look for white/yellowish gunk build up.
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(Post Link) post #8 of 28 Old 10-08-16 Thread Starter
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Originally Posted by a17esh View Post
Sniff test doesn't always work.

Fill your coolant to the brim with the cap off. Watch the engine warm up and keep and eye on the coolant. You will start to see bubble and more frequent as the car warms up.. - Head gasket for sure.

Other signs, cars heating may be cooler then normal. Coffee colour in the oil (look at dip stick). Look at the oil filler car, look for white/yellowish gunk build up.
Oil cap only has dark oil. Also does the dip stick. Had a transparent coffee color when the oil was new, as the oil had that colour.
In fact, the car now heats up faster, I guess only because it's summer. On mornings it reaches 90ļC on 5-6 minutes and sits there.
The thermostat is a bit worn, in winter it hardly went over 70. Look, you've reminded me another thing to change!

A video of the coolant tank. The squealing noise is the exhaust manifold leak, it goes away when it heats up.
The level was a bit low, I'll do that again with the coolant toped up.

http://www.youtube.com/watch?v=WaCmerAkQvo



The noise it does after a run (excess pressure releasing on cap):
https://www.youtube.com/watch?v=YOToQfCXsCQ
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Quote:
Originally Posted by dabyd64 View Post
Wouldn't it be cheaper a single test at a local workshop instead of buying the whole kit? I don't have plans to foock up the gasket from time to time :
Regards!
As with most tools they pay for themselves once used a couple of times. You sound pretty handy with the spanners so paying a garage to investigate the symptoms you've already taken considerable steps to investigate is a waste of money. Get the sniff kit as it's a great piece of kit to have in your tool box.
Not the be all and end all but more info for you diagnosis.
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(Post Link) post #10 of 28 Old 12-08-16 Thread Starter
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I've bought a smaller sniff test kit, for 15 bucks it gives 4-5 tests
http://www.ebay.co.uk/itm/112057164021
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(Post Link) post #11 of 28 Old 18-08-16 Thread Starter
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The oil and water are still ok. Refilled 1/2 litre of oil after 13.000km (8000 miles) since last change, so the oil consumption is normal.
The coolant color is darkening a bit, from the typical shocking red to a blood-like colour. Maybe it's be the exhaust fumes contaminating the coolant?
I made another video, totally cold. There's a white fog coming out. Looks like cylinder to coolant leak, exhaust gas evaporation some coolant?

I'm very very worried now. Saw that a lot of 159 2.4 had cracks in the head when they had removed it thinking on just bad gasket.
My engine uses the same head as the 159 (checked in ePer, head part no is the same as in the 2.4 159, brera, while 156/166 with 175hp engine use other head)
Cheers
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Hola !...
It is definitely head gasket problem. Than engine is running it create air pressure penetrating coolant system through faulty head gasket. Cooling system extra air pressure has released by coolant extension tank cap. Engine air pressure created is to high to let coolant go into engine than idling or riding but as soon as you stop engine and engine air pressure comes to zero, residual pressure from coolant system pushes coolant into engine chamber(s) back and you loose coolant with exhaust with next start. Temporary solution is to change coolant tank cap from 1,4 bar to 1,2 bar to reduce pressure to save coolant but it is rubbish. Just be ready to repair.
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Quote:
Originally Posted by dabyd64 View Post
I've bought a smaller sniff test kit, for 15 bucks it gives 4-5 tests
http://www.ebay.co.uk/itm/112057164021
Presumably this has confirmed the presence of hydrocarbons in the coolant.
Given the likely hood of a cracked head rather than gasket failure and the labour involved in fitting have you priced up a new head.

Ps. Didn't realise the 20v had swirl flaps. Would have been the engine of choice if made available in the gt.
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(Post Link) post #14 of 28 Old 18-08-16 Thread Starter
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Is the cracked head soo more likely to happen than just the gasket on the 2.4 20V?
Yes this one has swirl flaps, since 2005-2006 they started doing so due Euro4 emission regulations .
The 185hp has swirls, the 175hp doesn't.
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(Post Link) post #15 of 28 Old 22-08-16 Thread Starter
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Ebay's block test arrived, tested and liquid turned green, so definitely cracked head or gasket.
It's getting worse, drinks coolant faster than before.
But no white smoke, although I notice the sweet smell on exhaust, so that's it.
Strange that oil is still not mixing with coolant?
Cheers
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It won't mix oil & coolant if the head gasket leak is between a waterway and the cylinder, and the piston rings on that cylinder are good. The coolant that leaks in will stay in the cylinder and go out the exhaust on the next start, your oil stays uncontaminated.

Sounds like you need to pull the head off now, I would definitely advise getting the head crack-tested or even X-rayed.
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(Post Link) post #17 of 28 Old 22-08-16 Thread Starter
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Sure, crack test will be the first thing to do.
But for i'll wait until i can afford a head.
For now it runs well, doesn't overheat, if I lift the head now and find it cracked, I'll be without car for ataque least two months.if it's only the gasket then will be done in a week.
But can't take the risk!
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The true is open head might not be enough to judge correct.
Either crack or gasket failure could be too small and invisible.
The only thing you would see definitely is clean and shining piston(s) surface which shows exact cylinder (s) involved for coolant gone. This case crack test is to be done definitely and if test would be passed OK just to put new gasket.
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Wasn't going to test myself! No skills for that
It costs around 35euro to test on a local workshop.
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Hi again!
She has had an acceptable life for the last 3 months, topping the coolant every 2 weeks without other issues.
However, this week I had to top up twice in two days, and one of them was scary!
Coolant level was ok before driving, after 30 miles I saw the gauge a little bit over 90.
Having a half-knackered thermostat that usually sits on 70, I suspected and stopped inmediately.
Coolant was totally gone... I had to put 3 liters to reach just over the min!!
A lot of vapour came out of the reservoir... Omg... This looks BAD!
Once it cooled down a bit, I went back to home driving the softest I could... Didn't overheat again on the 30miles back, no strange noises... But this has come to a dead end, I can't risk any more with this... It was impossible to find a place to do it myself, so I've left her on the workshop.
They'll start removing bits on Monday, I'm pretty much worried, can't stop thinking on a cracked head!
I hope it's just the gasket... I'll keep updated.

If the head is ok, I will refurb inyectors,clean intake and null the swirl flaps, flatten exhaust manifold, clean the turbo vnt... A lot of work to do!
Regards
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Sad, sad , sad...
Head is cracked between exhaust and inlet valves on cylinders 2, 3 and 4...

Pics:
https://postimg.org/gallery/1mex6agv4/
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Unfortunately it seems to be quite common on the 20v engine now, bad news

Are you looking for a new head?
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Yes, Im looking for a new one.
Looking in Eper it seems that the 185bhp model uses the same head as the 159 and brera, not like the 175hp 156's and 166's.
I think I read somewhere that these heads are available with 5mm and 6mm exhaust valves, and these 6mm were made to fix those cracks, is it true?
Are they swappable? Can i put a 6mm valve head instead my 5mm's?
Or is the 156 20V head compatible with the 159's?
I'm in a serious hurry in search of a head!
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Ok, I discovered that the JTD 2.4 20V 175hp 156/166's have 6mm exhaust valves, and slightly different watter channels.
The 185/200/210hp engines have 5mm exhaust valves and wider water channels.

175hp head:
https://s19.postimg.org/garxv9bmb/culata_175.jpg

185/200/210hp head:
https://s19.postimg.org/ekdi7ijgz/cu...85_200_210.jpg

Why use smaller exhaust valves in a more powerful engine?
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The 5mm/6mm thing probably refers to the valve stem diameter
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