1.6 HDi Buying guide

[RichardW]

The 1.6 16V Hdi engine is everywhere, so it's inevitable that more and more members are going to be looking at them - it's really the only diesel choice unless you want to fork out for a high spec model with the 2.0 engine. However, there are a few issues with it - not least its reputation for eating turbos - which will rather spoil your day. The reputation is deserved, however, I believe that with a few careful checks and precautions, and a few hours labour you can insure yourself against it. First the problem is not actually the turbo - it is a tiny oil filter that is fitted in the banjo bolt in the inlet to the oil feed pipe. The engine is a bit prone to getting the oil a bit sludgy, and this then blocks the turbo oil filter, and goodnight turbo. Fit a new turbo without taking precautions and it will last only 2-3k miles. So, if you considering buying one....

1. Oil changes, and quality of oil are important. Look for a FSH - preferably a main dealer one, with no missed or late changes.
2. Check around the injectors for signs of blowby - particularly No 3 (counting from the cam belt end)
3. If you can pop off the inlet hose to the turbo and check for play in the shaft; if not, then listen to the turbo via a stethoscope for any untoward noises.
4. If possible get it on a Lexia, and check the pressures across the DPF filter - it should be close to zero at idle, and less than 50 - 60 at 3000 rpm.

If it passes these tests, and you get it home, it needs some intervention - the sooner the better!! You need to change the oil (only use a 5W30 low ash /SAPS oil - it's expensive, but cheaper than a turbo!). Drain the oil when hot, and only via the sump plug, keeping the car as level as possible during the draining. Next remove the filter in the turbo oil feed pipe. Sadly, this is as not as easy as it sounds. The banjo is screwed into the block behind the DPF, so this needs to be removed in order to get access to remove the bolt. In most cars, this will require the removal of the radiator, as otherwise there isn't enough room to get the heat shield out. Takes 3 or so hours the first time you do one....! Once the bolt is out, just pick out the strainer from the end of it. With this removed the turbo will be fine - ours survived a low oil pressure event (7k after it was replaced), caused in part by the vacuum pump, which beings me to the next point...

Once you have done this, remove the vacuum pump (RH side of the engine as you look at it) - really easy with the air pipes off, only 2 bolts holding it on (one is an extended one with a ball on the end to clip the air pipe on). You will find this also has a strainer on the inlet ( ) check this for any signs of blockage. If it's clean - bonza, bung it back in and you're good to go. If it's not, then take the top off the pump (note, I've not done this on a good one, so not sure exactly what you will find!). If there are signs of internal distress, with bits of plastic floating about, renew the pump.

Now, put it on a diet of oil changes every 6-8k and it should be good for a while. Monitor the inlet strainer on the vac pump - if it shows signs of blocking, then further action (sell it??!!) may be needed. Monitor also the injectors - check (carefully!) that the injector clamp bolts are tight at each service.

If you do get as far as a low oil pressure event, or the vac pump is blocking up, drop the sump, clean out the strainer, clean the vac pump strainer again, and put it back together. Monitor the vac pump again, and if it shows further signs of blocking, the drop the sump again, and this time remove the strainer mesh from the pick up.

It may all seem like a bit of a faff, but it's better than changing a turbo outside in January, trust me....!

If it all goes pear shaped, and the turbo does let go, then new cores are available on the bay for just over £100, and not too hard to fit DIY.

[KP]

There is certainly one bit i 100% agree with.

(sell it??!!)

[bxzx16v]

A great guide Richard, thanks for taking time out to write it. I think I've got lucky with mine but I'll be using your info though to keep it running sweet.

Mark

[Hell Razor5543]

I see that Richard has hit a purple patch!

[CitroJim]

I see that Richard has hit a purple patch!

I can make Richard any colour he wishes to be

[MikeT]

Appreciated Richard, thank you

[Hell Razor5543]

I see that Richard has hit a purple patch!

I can make Richard any colour he wishes to be

Rainbow coloured polka dots?

[CitroJim]

Appreciated Richard, thank you

Seconded Richard, a most excellent guide...

[Axa]

Should be a sticky!

Sent from my LT25i using Tapatalk

[spider]

Good topic.

I threw the filter out of my XU 205TD without any issue (despite being told against it) but it seemed difficult to get one and a new pipe did not come with one ( ! ) , no issues for seven years without it.

I'd not really want to leave any derv (or maybe petrol engine tbh) oil in for more than about 6K regardless of what any manufacturer said, ultimately its "warranty life" they are interested in as I mentioned ages ago about reducing the TCO for large fleet buyers...

[MikeT]

Monitor also the injectors - check (carefully!) that the injector clamp bolts are tight at each service.

Stupid question time, I'm afraid.

What measure does an inexperienced DIY'er rely on to tell what 4Nm plus 65degrees should feel like in order to "check they're tight"?

As you know, one of mine is blowing bad so thought I'd (carefully) try tightening the clamp nuts. They felt quite tight to me but as it was blowing, knew they had to be wound in further hoping not to shear the studs. I then tested resistance of the other injector clamp nuts and some of those were much much looser so tweaked turned them between 45 and 90 degrees accordingly. The engine sounds better for it.

Of course, I'll be getting new seals at some point but now realise my torque wrench isn't accurate for such a low setting (4Nm). And talking of seals, there appears to be possibly three inserts that "seal" the injector. Do all need to be renewed or just the copper ones? Should I get the revised clamps too as (I hope) they improve the chances of the nuts staying tight?

[Peter.N.]

For the last 50 years I have just pulled it down until it feels right which is OK if you know what it should feel like. I think once they have started leaking you will be lucky to stop the leak by pulling them down.

Peter

[Axa]

Vert important is to tighten the bolts only when engine are heated up to maximum temp!
Check all bolts first and try to note how tight the tightest loose bolts feels. As long as not tighten any of the looser bolts harder then the tightest loose one, the bolts should stay within the limit of breaking as long as they have not been tightened before.

[MikeT]

I don't intend touching them again until I renew the seals etc but just wondering for future inspections. I guess I'll get a feel of the correct torque when I do the job with new parts. Thanks.

BTW, having spoke to Citroen. they advise using new studs (if you can get them out!) and nuts as they're torque-to-yield. Thoughts?

[harryp]

My other half just having purchased a late 2013 C4 picasso 1.6... am interested in this thread; obviously . To me all the advice, esp on oil changes seems very sound and the turbo filters interesting, etc., etc. I am always puzzled by manufacturers supplying "torque to yield" bolts. I was always taught that for max tightness a bolt should always stretch within it's "elastic limit". Also that by so doing it is reuseable. ?? Overtightening it past it's yield point would lead to a reduction in clamping force and probable failure Just what is the score on this one. I admit to my training being 50 years ago, but has metallurgy changed ?