Burning smell from front

[TomPaine]

Evening all. I've noticed a burnt electrics smell from the grill the last few times I've parked up. I'd probably not have noticed it in the street but the car is garaged when dry, which has trapped the smell a bit. Nothing inside the cabin. Could this be warning of a failing DI or would that simply fail before emitting any smell? There's no CEL or any other symptom. Looking at my records it's about 7 years and c50k miles old, which might put it in the fail zone ...

[sgould]

Next time you smell it, open the bonnet and see if you can locate the source more accurately.   I had a panic over a burnt, plasticy sort of smell, and that turned out to be an old plastic fertiliser bag that had melted onto the exhaust!!

The throttle body gets very hot and plastic falls off the wires inside.  But, if not the DI, I would be looking for something touching the exhaust.  If an electrical component smells like that it usually fails fairly quickly.  The hottest bits are the resistors around the radiator. They may take a while to fail.

[TomPaine]

Thanks Will. Yes, I remember your melting bag saga ...

I will try to get a better look next time. Googling had suggested that this sort of smell could portend a failing DI, e.g.

https://www.eeuroparts.com/blog/10-problems-commonly-associated-saab-9-5/

but I wondered if anyone had ever had that sort of warning pre-failure (rather than after it had gone pop).

I'll report back when I can.

[fka]

I had a melting plastic smell on the 9-3 which coincided with me seeing abnormal misfires. As I found one of the components in the DIc had melted, I always attributed the smell to that and didn't smell it again after replacing the DIC. Can't be sure that was what the smell was though.
If you don't find anything else obvious, you can always take the DIC apart and see what state it's in and if you have open SID, you'd expect to see misfires when the engine's under load if the DIC is on it's way out.

[TomPaine]

Well, I'm stumped tbh. I ran her up to temp today and then had a good look / sniff ...

Certainly no actual wisps of smoke that would make detection easy. No plastic stuck anywhere, nor any drops of oil that I could see. There was no smell particularly around the DI. It seemed to be strongest basically in the gap between the engine block and the battery, behind the radiator fan. I can't be more precise than that. With no CEL and the engine temp fine I don't think I can do much else but carry on, with the AA card to hand ...

[steventon95]

I'm going to join the party. I just came back from my Essential Shopping, onto the drive and a smell of burning rubber and interesting quantity of smoke. I have't dared to try restarting it yet, I'm just sitting back and having a think about it . No CEL light at all. I'm think that it might be auxiliary belt slipping into destruction (cheap part but a bit of a PITA to get out). 136,000 on the clock so not unreasonable. A little later I'll try a restart and see where the smoke is coming from.

[TomPaine]

Commiserations - sounds different from mine. Mine you wouldn't notice unless you were up close. Indeed the car is garaged; so I smell it cos it's trapped at the front of the garage after I'd driven in; I suspect that I wouldn't detect it if it was parked outside. I've been quite tempted to have a sniff of other recenrtly driven cars to see whether I was just being over-sensitive, but fear arrest ...

(I'm hoping to get the car serviced soon and will report back if I get any intel re my issue.)

[steventon95]

Well I upped the bonnet and got Mrs to start her up. Copious smoke from suspect end of the engine, and a very quick turning off. It's looking more and more likely it's the belt. More news next week

[carrera]

As you seem to have a spare car I would whip the belt off (use the 3mm allen key in the tensioner) and test to be sure of the diagnosis. It'll be ready for the replacement belt when it arrives then 

[steventon95]

I am of an age when I don't delve too far into the workings. The belt is a bit of a swine to get to, but giving it a prod through the modest gaps available suggests it is there and there is reasonable tension. The worry then becomes what is the state of play with the various driven objects (alternator must be OK as no indication on the dash and no CEL) but steering pump? AC pump? Oh well, it's booked in tomorrow, so I will find out soon enough. I hope it's not too disastrous as the car is not worth a bunch, but I'm quite fond of it.

[carrera]

Ah, OK, fair enough, I ws thinking this was a DIY job. It'll probably take as long to get the car on and off the ramp as to do the actual job if that helps

[steventon95]

Well, having a booking at our local independent I decided to put the other 95 in for a sort out instead as that was starting to make untoward noises from the steering department (160,000 on the clock). That proved to be corroded pipework. I have had this one before, it is apparently quite popular and original parts have dried up. However, I've managed to find a complete pattern set so that one should get sorted. Then back to the other one with the burning rubber smell and smoke which will have to wait until next week. Happy days!

[carrera]

The power steering pipes do rust, have a look at the 4th picture here http://www.saabtechtalk.com/forum/index.php?topic=4176.0. It's the brown rusty one, as opposed to the rubber pipe linking the oil cooler inlet and outlet, which is there because the oil cooler pipe was previously leaking due to rust.They are all just a bit exposed at the front.

That said, I'm not sure how corroded pipework can cause a noise though, unless it had become leaky and power steering fluid had been lost ?

[steventon95]

All done and normal service resumed on the Aero Estate. The other one will have to wait until next week.

[TomPaine]

Commiserations - sounds different from mine. Mine you wouldn't notice unless you were up close. Indeed the car is garaged; so I smell it cos it's trapped at the front of the garage after I'd driven in; I suspect that I wouldn't detect it if it was parked outside. I've been quite tempted to have a sniff of other recenrtly driven cars to see whether I was just being over-sensitive, but fear arrest ... (I'm hoping to get the car serviced soon and will report back if I get any intel re my issue.)

And to report on mine, at service nothing thought to be amiss and just normal hot engine smell. Fingers crossed.