Activa Buyers Guide

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CitroJim
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Activa Buyers Guide

Post by CitroJim »

Generally speaking, the Activa is very similar to a normal Xantia and all the usual checks apply when vetting a potential purchase. So look carefully at Strut Tops, the Heater Matrix and so on. This guide will concentrate on those areas to check that are very much Activa-Specific.

If you have no pevious experience of an Activa and are contemplating the purchase of one, try to take an experienced owner with you.

I'm leaving suspension to last :lol:

Engine

The Activa is fitted with the XU10J2CTE. This is a 2L 8V XU engine of quite old and traditional design. It was borrowed from the XM for the Activa and is also found in the Xantia CT Turbo Estate in the UK although they're rare.

The "CT" designation stands for "Constant Torque" and as the name suggests, this engine majors on torque. It has bucketloads from rather low revs, much like a diesel. It achives this torque through the use of a low-pressure turbocharger (0.8 bar max boost). The engine is not tuned for out and out power and is not going to blow your socks off, nor does the boost make it's presence much felt; rather it's there all the time in the form of big dollops of torque and this alow the car to pull high gear ratios normally the preserve of a diesel.

The engine is massivly over-engineered and in a relatively low state of tune and is therefore pretty much bomb-proof. They do run hot though so it is essential that the cooling system is in top condition. Look at the coolant and check for good, clean anti-freeze. It is essential to maintain good anti-freeze to prevent corrosion in the alloy head and to preserve the turbo, which is water cooled. Check the rad and ensure it is hot all over and not weeping. rads usually need replacing after about 8 years/100K. Activa rads are not easily available but the good news is that the 2.1TD rad is identical.

The engine should run at 80degrees when on the move but don't be alarmed that the gauge quickly rises to 90 when stopped/idling in traffic. The cooling system gets a lot of heat dumped from the turbo and oil cooler. At 90 degrees the cooling fans will start. Ensure they are working well and that they bring the temperature down in good time. Fans work hard and if they fail, overheating is a risk. The engine should have an 82 degree thermostat fitted. Often these are replaced with an 88 degree item. If such a 'stat appears to be fitted, change it for an 82 degree one soonest.

The engine will seem a little lumpy on idle. Quite normal. It should, however, rev cleanly and be smooth when at speed. It shoud esily red-line. Don't be alarmed if it misfires like crazy just past the red-line. It's hit the rather crude rev-limiter!

The engine, once off idle, where they can be a little noisy, should be dead quiet with no mechanical noise.

The turbo should be silent. They wear well and any strange mechanical noises from the area of the turbo means hard work to come.

Check the top engine mount donuts, especially the little one at the rear. They often fail and cause a clunking noise on drive takeup.

Cambelts need changing regularly. Listen for a whine from the tensioner. The cambelt is dead easy to replace on this engine, as is the tensioner although it's an eccentric tensiner and it needs care in adjustment.

Check the Engine Management Light goes out straight away on start. If it lingers for a few seconds after a start, the ECU has a fault or faults stored, requiring a diagnostics test to determine what they are.

Beware of after-market boost controllers being fitted. The ECU will log a fault if the boost exceeds 1 bar.

Gearbox

The Activa uses the ML5T 'box as found on the 2.1TD and 110 HDi Xantias. It has a hydraulic clutch. Generally the ML5T is a tough 'box and gives little trouble. Just ensure the synchromesh works OK on all gears. The gearchange is cable operated. Check the gearstick is not floppy, has no exesss play and all gears engage positively. A loose, sloppy gearchange is a sign the cables are worn. On a MK1 this is a very expensive business to resolve. A MK2 uses a different cable mechanism and is considerably cheaper to resolve problems.

The clutch should be light and positive. If there is a hydraulic problem, run away! The Master and Slave cylinders have to be replaced as a complete unit and they are very expensive as well as difficult. Clutch changes too are more difficult than on a BE3 'box due to the need for special tools to replace the release bearing. On the plus side, there is no clutch clip to worry about.

Suspension

This is where the Activa differs radically. It has the whole works: Hydractive II, Anti-Sink and Active Anti-Roll. It has ten spheres and plenty to go very wrong :twisted:

The first check is to start up and watch the STOP Lamp. It will take an age to go off as pressure builds. Remember there are ten spheres and two big Activa Rams to bring up to pressure. If the car was low on it's suspension (a lot of Activas do sink a a little) it may jerk sideways as it achieves normal ride height. This is normal. Expect the STOP light to take about 30s or longer to go off if the car has been idel for some hours.

Observe the car from the front or rear from a distance. Is it level side-to-side or is it leaning? If it is leaning, suspect binding or wear in the roll corrector linkages or guide blocks. This is cheap and easy to resolve. If the wear is severe, the car may rock and perform the "Activa Shuffle" when stationary.

Set the suspension on high. It will rise quite slowly and it may jerk a little. Check the LHM level and also, whilst you're there check its condition. A very low level of LHM or old LHM should sound warning bells.

When on high, get down and look at the rams. The front ram is on the nearside and takes the place of a drop link on the Anti Roll Bar. Is it dry? Is there a drip of LHM from it's end. Check the rear ram which is on the offside and again takes the place of a drop link. If either or both rams are leaking, big bills loom. They're £300 each roughly. A bit of dampness on the rams can be lived with but outright drippy leaks are an MOT fail. Sometimes the leak is just a broken leakage return spigot on the ram and this can be repaired with care.

Look for any other LHM leaks. Check the spheres fitted are in fact proper Activa spheres as almost all of them are unique to the Activa and not easy to get hold of now.

Do "Citarobics" and ensure the car responds as expected although it'll be slower to react than a normal Xantia. Ensure it falls from high to normal properly and rises from low to normal correctly. The STOP light may illuminate briefly whilst it goes from low to normal. Check the accumulator tick rate is well in excess of 30s.

When on normal height, look under the rear of the front wheelarches for the roll corrector linkage balljoints. Grab one and pull it toward you. the car should tilt towards you. Let go and it should level and push it awaty from you and it shout tilt the other way. This confirms the basic Activa system is working.

Do the normal Hydractive Electrovalve tests by checking the suspension switches from hard to soft as expected. This thread tells how to test the hydractive side and also some more in-depth tests of the Activa system.


Test Drive

Very important!

The engine may not feel as lively as you may expect a turbo to feel. It should however pull lustily from low revs right up to the red-line. Dont expect a sudden rush of power as the turbo comes in. They don't do that. Power and torque just builds gracefully in large quantities. The car should be quick though but without any drama. A bit of turbo lag is normal. Remember the Activa is a Gentlemans GT!

It should feel very nimble on it's suspension and it'll feel harder (and harsher) than a mormal Xantia. It should not roll one iota and you should not feel it roll correcting overtly. You should be able to tell the roll correction is working even by going quite slowly around a roundabout. A great test is to flick it around S bends or just flick it fast through a roundabout. It should remain poised and totally unruffled. Any faults on the suspension generally or the Activa system in paricular will make the car handle dreadfully and in fact make it dangerous. In short, handling should be faultless in all areas.

Listen for clunks from the rear when going over bumps. If the rear is really noisy, this is a sign the rear ram bush has failed. It's a tiny bush and makes lost of noise out of all proportion to its size! It's easy to replace but very expensive at £180 'odd. I can make a substitute bush from nylon if necessary for pennies. It's a good bargaining point though. Generally the suspension should be reasonably quiet over bumps but as it's harder than a normal Xantia, it will be noisier. Clunks and thuds are not normal though.

The Other Bits

Activas have unique wheels (actually no, some 2.1TDs had them too) they last well but look for kerbing damage. If scruffy, they refinish well.

Leather seats are generally all electric and heated. The heaters often fail and can be lived without but do check all the electric adjustments work. The seats cannot be removed for repair unless the electric slide back/forward is working!

Check all the toys work! Check the oil temperature gauge works.

Some items on an Activa are specific, such as Spheres, rams and etc. Everything else will be different to say a 1.9TD and some bits will not appear to be available from the usual sources. As a general rule, the 2.1TD shares many, many bits with the Activa so if a specific item (e.g. the radiator) is not listed for an Activa, chances are the same item listed for the 2.1TD will fit. There are also some parts common with the 110 HDi.

There will be much I've forgotten. Feel free to add to this guide.
Last edited by CitroJim on 11 Oct 2008, 22:18, edited 1 time in total.
Jim

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Post by andmcit »

A picture speaks a 1000 words, so here's a few!

Image
Image
Image
Image

and overview links outlining suspension system:
http://www.ukcar.co.uk/features/tech/su ... activa.htm
http://www.citroen.mb.ca/citroen_quarte ... ctiva.html

Intersperse these among the text if you like Jim!!

It may be worth mentioning the context of what hydractive and the VSX
set up actually offers over the normal Xantia hydropneumatic suspension.

Andrew
Last edited by andmcit on 12 Oct 2008, 01:58, edited 2 times in total.
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Post by CitroJim »

Thanks Andrew :D Excellent
andmcit wrote: It may be worth mentioning the context of what hydractive and the VSX
set up actually offers over the normal Xantia hydropneumatic suspension.

Andrew
Yes, good point. Hydractive suspension has two distinct modes of operation, hard and soft. Under normal running, the suspension will spend most of its time in soft mode if everything is working properly. The suspension will switch to hard mode under certain conditions. These include hard braking, hard accelleration, hard cornering and any time the suspension feels it is about to bottom out. A myriad of sensors determin conditions and theses feed into an ECU that makes the decision when to switch. Sensors include speed, rate of change of stering angle, brake pressure, throttle position and yaw. A Hydractive car is very soft and comfy when in soft mode but will switch to hard mode in an instant when the aforesaid conditions happen. It will switch back to soft just as quickly. In practice you really don't feel it happening.

All Hydractive cars have a normal/sport switch down by the height lever in MK1s and on the dash on MK2s. This switch simply changes the thresholds at which the suspension switches from soft to hard and back again. In sport mode, the suspension will switch much more readily and even on an Activa it sharpens the handling somewhat.

The hard/soft ride is achieved by switching an additional sphere in and out of circuit, both back and front, called the Hydractive Centre Sphere. This sphere handles the soft side of things and is hydraulically switched into circuit by an electrovale under control of the Hydractive ECU. In hard mode, the sphere is switched out and suspension stiffness is then determined by the suspension corner spheres alone. These are much harder than normal corner spheres.

An Activa has two more spheres, the Activa Accumulator and Activa Balancing Sphere. The Accumulator supplies a reserve of pressure for the Activa roll correction rams whilst the balancing sphere acts as a spring between the front and rear rams and provides some "give" in the otherwise very stiff anti roll bars. The balancing sphere is switched in and out under ECU control to provide either soft or hard roll correction and switches modes under much the same circumstances as the hydractive system.

For a more in-depth description of the Hydractive and the Activa system, Have a look at the Citroen Technical Guide.
Jim

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Post by red_dwarfers »

These leaking Activa rams - is it not possible just to replace the seals?

Theres a hydraulic specialist local to me that managed to make me up a seal kit for the hyrostatic steering ram on my old tractor.

Something that been bugging me also, is the hydractive suspension more comfortable than standard hydropnematic?
Kev

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Post by CitroJim »

Hi Kev,

Sadly, at this time, the rams are seen as not economical to repair as they're not built in a way that allows them to be easily disassembled. That's not to say it's impossible though and I understand Martin at Pleiades has a project, although very much on the back burner at the moment, to look into the possibility of reconditioning them.

Hydractive is more comfortable and gives better handing. The ride comfort of a Hydractive Xantia (not an Activa) with excellent spheres and everything working well has to be experienced to be believed :D

An Activa is much harder even in soft mode than a normal Hydractive so you don't reap the comfort benefits to such a degree. They're comfy but set up to handle. You don't realise how comfy they are until you drive say, a 205GTi. The 205GTi will rattle the fillings out of your teeth to approach the Activa level of handling whereas the Activa is rather more gentle on it's driver and passengers to achieve the same.
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Re: Activa Buyers Guide

Post by XantiaMan »

CitroJim wrote: The Activa is fitted with the XU10J2CTE. This is a 2L 8V XU engine of quite old and traditional design. It was borrowed from the XM for the Activa and is also found in the Xantia CT Turbo Estate in the UK although they're rare.

The "CT" designation stands for "Constant Torque" and as the name suggests, this engine majors on torque. It has bucketloads from rather low revs, much like a diesel. It achives this torque through the use of a low-pressure turbocharger (0.8 bar max boost). The engine is not tuned for out and out power and is not going to blow
I would like to add if i may, that the maximum boost pressure you are likely to see is around 0.65 BAR, which equates to just over 9psi. This boost is modulated throughout the rev range to smooth the torque curve and this eliminates the 'peaky' feel of a full pressure turbocharged engine.
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Post by andmcit »

Just found these of a relatively new front ram I had which show the vulnerable
leak off pipe that normally fails causing MOT and LHM hassles:

Image
Image
Image

Helps visualise to someone new to Activae what may be wrong and leaking on
their new/prospective purchase!

Andrew
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Post by CitroJim »

Thanks Andrew :D Brilliant!
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