My dad has a Saab 9-5, 3ltr diesel - 2002 with about 75k on the clock. It increasingly keeps going into limp-home mode and now spends most of its time in this mode. Ironically it didn't do this before it was serviced.

Any advice on what could cause this problem? It has to be said that it's mostly used for short runs which is not ideal for this sort of car. I don't know much about diesels but did wonder if there's some sort of carbon recyle system that's plugged up.

Also - does anyone know what grade of oil should be in it? Sounds like a daft question but the garage and user manual don't agree on this and he wonders if it just has the wrong oil grade in it..


Thanks

Might be worth doing a search on DPF (Diesel Particulate Filters) which can cause problems . Not sure if your Saab has one fitted but would be around the time manufacturers started fitting them. Sometimes a good thrashing will clear them (self generation) It may be possible to clean it , Forte have an additive that they reckon will do the job but as yet I haven't tried it. Before doing anything else scan for fault codes or try disconnection the air flow meter, if it goes better then the air flow meter is faulty

could be lots of things - check all the hoses for splits is the first thing to check followed by the cleaning the EGR unit.

Best answer is to visit a Saab specialist who will diagnose with a techII though

Cheers

M

As said could be anything, save a lot of messing and get it plugged in, I've got one for my saab, but I'm a way from you
unlikely oil though

5w/30 or 5w/40 fully synthetic --- change at least every 10,000 ---- if I had one I would use 5w/30 changed every 5,000 miles.

I had similar with my 52 plate 3.0TiD saab 9-5... symptoms pointed to a knackered EGR forums agreed..

I dismantled it to find it fine... so I purchased a OBD2 reader and found it to be the MAP sensor was faulty, swaped it for a new one (£150!!) and its been fine ever since.

my sprinter did that all the time when the intercooler was leaking, but that made an obvious noise. It could be a small air leak somewhere though, or all the above