The camshafts on the GSA

or Why does the engine sound like a machine gun?

The camshafts (yes, there are actually two on the GSA engines. Because the cylinders are mounted horisontally opposed two and two, there are two cylinder heads and consequently two camshafts) have a tendancy to wear down for different reasons, with the result that the engine starts making a more-or-less loud clattering noise. Sometimes it's difficult to hear the sound unless you're inside the car - it then sounds like deep repeated banging somewhere at the front of the car.

Many people have tried selling GSA's with more or less worn-out cams with arguments like That's what all Citroëns sound like or It's only the valves that need adjusting. Don't you believe it! It's the cams and their associated rocker arms that need replacing and the job can cost quite a bit both in parts and time. The alternative is simply to endure the sound. The engine won't care; it runs nicely anyway - even if it's banging away nicely it can run for thousands of miles without increased fuel consumption or other problems.

Reasons for camshaft wear

The camshafts are supposed to open the valves, and anyone whose tried to compress a valve spring in a dismantled engine knows that it's no easy task. One can make cams and rockers in a strong or reinforced material, but you still need ample lubrication for the parts to last. Camshafts wearing down is thus a result of bad lubrication, and what does that depend on?, Well...

Cold starting. Cold oil won't flow as easily as warm oil does.
Low r.p.m.s. At low r.p.m.s it's difficult to obtain sufficient oil pressure for the oil to reach all parts of the engine.
Old or bad oil. Engine oil has quite a few additives to improve its qualities, but when the oil is old these additives have deteriorated and thus loose their effect. The result is that the oil fails to lubricate properly, or gums up oilways. In an air-cooled engine the engine is also more dependent on the oil as a cooling medium (the GSA is equipped with an oil cooler for this reason), which puts higher demands on the oil.
Old oil filters. The oil filter is supposed to clean the engine oil, and if it can't perform its task due clogging up the oil wears out faster.

The 1300cc GSA engines are usually more sensitive than the older 1220cc engines used in the GS. One theory is that the material in the cams has been replaced with something softer, and cheaper, but it could also be one of the above reasons. At about the same time as the GSA engines were launched, the 5-speed gearbox appeared, and there is a temptation to use the 5:th gear at too low speeds. The oil change intervals have also (due to improvements in engine oil technology) been increased from 5000 km on the GS to 7500 km on the GSA. This results in smaller margins, especially when using cheap oil or skipping a few oil changes.

So...what can you do about it?

Once the chattering has begun you can't improve the situation without renovating the engine, but you can try to stop things from getting worse. There are a few preventive measures that can be taken:

Change oil regularly! As mentioned previously an oil change on a GSA is a simple operation. The oil has to be replaced every 7500 kilometers; some would say that decreasing this interval won't hurt.
Use a good quality oil from a well-known brand. Taking into consideration how cheap oil is in comparison to the cost of the amount of gas consumed during the same time, there is no reason to save a few bucks by buying 'department-store oil'.
Change the oil filter regularly. According to some people, non-original filters result in too low an oil pressure in the engine. In the technical data section of the manual it says that the filter should be of a special Citroën-approved design, whatever that means. Another suggestion is to replace the filter when replacing the oil, not at every second oil change as is described in the service requirements.
Don't underturn the engine. Don't drive in 5:th gear at 50 km/h, instead, put it in 4:th and enjoy the softly whining engine sound at 2000 r.p.m.
Don't cold-start the engine. Install an engine heater if possible, and don't just drive short distances so that the engine has time to reach its proper operating temperature.

My own guidelines

I'm definitely no expert at this subject, I just want to keep my car rolling as long as possible. My own personal guidelines are described in the following.

Regular oil changes, every 7500 km, and oil filter changes, every 15000 km.
Good oil. I use Castrol or Valvoline 10W-40 mineral oil. 10W-40 flows more easily at low temperatures than the 15W-40 recommended in the manual. In the servicing recommendations it says to use oil of the API service grade SE, so modern oils of SF, SG or SH grade should be even better.
During continuous driving I never let the engine turn at less than 2000 r.p.m.
Never let the engine drop below 900-950 r.p.m. at idle. When the engine is cold you can accomplish this easily with the choke and the fast idle (if it works!), and when the engine is warm but newly started with the accelerator or possibly the choke.
An engine heater...now that's a good thought :-)

...and the result? Well, my car had a slight ticking on the right-hand side of the engine when I bought it, which could be the camshaft, or something else. After having driven over 25000 km I can't say that the sound has become much worse, even though it's difficult to make an objective comparison over such a long time. Also, the engine sound tends to vary with the seasons - when it's warmer engines tend to make more clatter.

Finally...if anyone has any comments, other points of view, or hints or tips, don't hesitate to drop me an email!

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