Practically Classics Forum

I've read that smoke machines are the best way to uncover hard to find vacuum leaks on modern cars, but the price of such equipment runs into several hundreds of pounds. I'm not really in a position to spend that kind of money on a professional smoke machine built specifically for this task, but wondered if a cheaper homemade alternative could be created for a fraction of the price?

Looking on ebay I came across cheap smoke/fog machines like the one below and wondered whether they could be somehow safely modifed to do the same thing as a professional smoke machine?

DJ smoke machine

I realise that there are other methods for locating vacuum leaks, but this method really appealed to me (provided it could be done without causing any damage). I know it's not something one would use everyday, but with garage labour charges rising ever upward, I would be quite happy having for a rainy day as they say.

Any input would be appreciated.

Thanks

Steve

I checked for (and found) the vacuum leak on my modern diesel by spraying brake cleaner about the same as on a classic. Engine revved up and I found a cracked hose.

WHS^^ any solvent spray or even WD40 will easily highlight a leak by either revving up or spluttering.
Its even more accurate if you have an exhaust gas analyser as well as the slightest ingestion of a solvent makes the reading shoot up.

Evaporative smoke machines cost several thousand, not sure a dj machine will do the same job

OT Im afraid but a client has a new(ish) Astra (2010) diesel and management light came on. This was bought from the local main agent Vauxhall dealer at FULL money. He duly took it back under warranty (I was with him) and the old-timer (proper) mechanic plugged in the 'computer' etc and ran through the results - you have an air leak somewhere sir - that was really handy as we knew that already - it still didn't tel him where and they had to do it all by hand/eye/blind to find it. Took ages. Same car needed (Vauxhall diagnosis) squeak from clutch when not depressed at idle - new DMF and associated bits £1400 - 12k miles - then told it was new (ish) and dropped to £700.... He had to pay. Also alarm kept going off and eventually flat battery - faulty alternator diagnosed- £600 - all under 25k. The dipstick agreed and paid for all of these and then changed it - for another Astra.....what can you do...