106 1.4D TUD3 Cooling reservoir pressurising

Hi to all and sorry my first post is one requiring help but I guess we all have to start on here somewhere?

We bought an L plate 1.4D 106 a few weeks ago (ebay) with the idea that it would be a good runabout to save wear and tear (plus fuel) on our two much larger 4x4. Thought I had done my homework but not too well it appears. The 1.4D is the one to avoid and the 1.5 is the one to go for. Ho, hum. Overall the car is in very nice condition and came with a new MOT.

So we get it come and I notice after the 35 mile run back that the coolant res is leaking fluid and hissing. OMG! Head gasket methinks! But before I dive into it I think I had better give everything else a full service/check over. Coolant system was stripped down to find a previous owner had had overheating problems and the thermostat had been removed. Checked the fan switch and the thermal switch for the overtemp indicator and they all look to have been replaced recently and all work. So it isn't overheating now. Flushed the whole system though around 4 times and then flushed again with water a further 8 times to make sure all the flushing agent is out.

No bleeding. I made a 'header tank' from a funnel jammed in the expansion bottle so the coolant is around 3" higher than any other point in the engine. Used both the bleed on the fuel pump and the one on the heater pipe return. Now when you start from cold there are no bubbles but after 2-3 minutes you start to get a stream of very small ones forming and coming out of the 'header'. My assumption was that wherever the coolant to combustion chamber leak was it must be very small. There is no water in the sump oil and the engine is running sweet.

So the cooling system is now VERY clean and fitted with a new 'stat and a new expansion bottle cap. So I have just added some Cargo/Kalimex Seal-Up (copper/liquid glass stuff) into the cooling system with just water to hopefully seal the leak. We have now been running around with this in the system for around 50 miles but we still get pressurisation - but the water level ,if it is falling, is almost unnoticable. It just hisses like puffing billy after I pull up for about a minute. Then it stops. Once the leak is 'sealed' I will then drain down and refill with the correct coolant mix. But for now the stuff stays in and I hope we don't suddenly get a Siberian Winter hitting us in the Spring down here in Wilts.

So the question is, for those of you who have more experience than I in TUD3 lumps, will the system pressurise enough to leak gas after the engine has got up to temp and done a bit of a run? As above, the engine seems to be running and pulling very nicely. The idea of stripping and changing the HG is not one I look forward to especially I now note that after skimming the shims will prob need changing in the valve train as well + possible liner shift!

Cheers,
Paul

[CitroJim]

Hi Paul,

Welcome to the forum although I would rather it was in happier circumstances..

I'm afraid all symptoms point to the head gasket failing. The TUD3, as you know, is a bit prone to this unfortunately. The stream of bubbles is a dead give-away and it is very rare any PSA engine mixes coolant and oil unless the fail is really bad. Pressurisation is almost always the first sign on these and XUD engines.

Sadly, the seller knew there was a problem and tried to hide it

It soulds like the Kalimex stuff has partially sealed it for now. It can do some wonderful things but I fear it may not be for long due to the nature of how these engines go. In the case of a conventional iron blocked engine this stuff has done the trick in some instances but I think on an alloy blocked/linered engine, its success may not be guaranteed due to the fundamental problem being liner shift.

In a diesel, even a little one, there is a tremendous combustion pressure, far higher than in a petrol engine, and it takes only a tiny, tiny leak to cause coolant pressurisation which any chemical fix will ultimately have trouble holding back for very long. These small pressurisation leaks have no discernable effect on engine running at all.

If the car is otherwise very tidy, it'll be worth doing. The head will need a light skim and the liner protrusion will need to be checked. Unless it needs skimming to the extent that the valve seats need to be replaced deeper in the head, it is very unlikely you'll need to reshim. The actual head-off job is not that difficult.

Again, depending on the condition of the car, it may be worth doing a TUD5 transplant. That is an intrinsically more reliable engine, being iron blocked and not so prone to the TUD3 troubles.

Fingers crossed the Kalimex keeps it going just long enough to do a permanant fix. Don't let it overheat though because that'll likely wreck the head. I once saw a 1.9TD XU head that had overheated and not only was it banana-shaped but annealed beyond use as well. Yet another had holes melted in the combustion chambers.

Cheers for the quick mail back Jim and you have suggested exactly what I have been thinking in the back of my mind all along

Now how easy or should I say problematic are these heads to change? I have pulled early Vauxhall heads and A-series before but they are all cast iron. So the basic ability is here. I just have to decide whether it is worth the amount of headache compared to moving the car on to someone who wants a cheap runabout and a challenge.

I have seen mention of the possibility of liner shift when the head is removed. That's why Haynes 'book-O-lies' mentions using a specially made bent levers to tilt the head away from the block. How critical is this or is it a bit of an exageration?

Getting a basic skim done shouldn't be difficult it's the valve issues that worried me.

How easy is a TUD5 swap? Do the engine mounts/ex mani etc. match up or are there a lot more interconn headaches?

Cheers, Paul

[CitroJim]

I've never done a TU head Paul, I must confess, but I have done a few XU and XUD heads, which are broadly similar, especially the Alloy XU as fitted to the 205GTi. It is not as difficult as it sounds. If you can do a BL "A" series head, you can do one of these I've done a few of those too.

The main struggle-point will be taking off the manifolds and battling possibly well tight and rusty studs as well as access although not having a turbo in the way will help matters considerably in this respect. You may be lucky and find the head will lift off with the exhaust mainfold in place. I don't know.

The next issue is the head studs. They're stretchy bolts and can snap if you don't approach them in the right way. The trick is to use a BIG breaker bar on them and apply gentle and constant pressure. You may feel the stud feeling "elasticky". Continue to hold the torque on it and let it unscrew at it's own pace, going slowly and don't try to pass the elasticky point. Let the stud catch you up as it were.

As you say, the main thing is not to disturb the liners so don't lift the head straight up but rock it back and forth to break the seal between the liner tops and the head. Don't lever between head and block. Once the head is off, prevent the liners from moving by using big washers on head studs to clamp the liners down. If you are really careful not to move the pistons, you can manage without but for safety use washers. If a liner moves, you'll break the very fragile O ring seals on the bottoms of the liners and end up with coolant in the sump. The BoL is not exaggerating the importance of not disturbing the liners!

Obviously the timing belt has to come off but you should be able to leave the cam in place. On the XUD, the injection pump can stay put but I don't know if that is the case with the TUD. In any case the injector pipes have to come off. Take care to ensure no dirt or muck can get in so carefully seal the exposed pump and injector unions and keep the pipes somewhere clean. Take care with any spilt diesel. It can cause contact dermatitis in some people.

The head will need to be stripped for a skim but some skimmers are happy for the valves to stay in. Ensure that all parts of the valve train are kept in strict order as you strip it. A good skimmer will pressure test your head to ensure it is free of cracks and for this they often prefer the valves to be left in. As I say, you'll be very unlucky if you need to reset the valve clearances.

As they say, reassembly is a reversal but do check the liner protrusion is in spec. Do clean up the block and liner faces well and do observe very carefully the head stud tightening sequence and procedure. The BoL should tell you to ensure the head stud threads in the block are spotlessly clean to ensure the torque and angle-tightening figures pan out correctly. Use a tap or an old head stud with flutes hacksawed in as a substitute tap to clean up the threads. Always replace the head bolts with new ones. Despite some saying you can if they have not stretched beyond a certain length, I would never re-use a stretch bolt under any circumstances.

On the TUD3 to TUD5 swap I don't know unfortunately. Hopefully someone else on here does.

Hope that helps a little Paul..

Well I fixed the problem or should I say I have moved the problem on

106 up on Eboy Monday with an honest write up. I'm not going to be dishonest like the original seller. Don't have the time to pull the head really Jim so let's see how much I lose when being honest?

If anyone is interested it is 170210258950 . Mods please feel free to delete that if it breaks site rules.

Solution Jim was a 1998 Zest 2 diesel I picked up for £750 with 100k on the odo. Needed a good clean and a major service but all looks good So far driven about 100 miles in it without fault and all it needs are some plastic clips to hold the bump trim onto the door. Pulled it off for the moment. Looks scruffy but better than someone catching it and ripping it off for now?

Lucas FIP though

Cheers for the advice Jim