Solution for intermittent no-start/no-run problem

[crossroads]

You may find this reply to be rather long but you need not read the Details section unless you wish to follow the specific symptoms preceding the solution.

Vehicle: 1999 Oldsmobile Intrigue 3.5L

Issue: Vehicle will occasionally not start or not run. Engine may also stop while driving.

Solution: Faulty ignition switch. (Replace or disassemble and clean contacts)

Discovery: Ignition switch was removed from vehicle and disassembled. Start and run circuit contacts exhibited mild burning/smut build-up leading to intermittent high resistance or opening of start and run circuits. Contacts were cleaned and switch reassembled. Leads and connections to switch appeared to be in good condition. Issue has failed to reappear.

Details: Between April-August '03 vehicle began exhibiting with increasing frequency one of four conditions:

1) will not crank,
2) cranks w/o starting,
3) starts but will die immediately or run for short period (3-5 sec) then die,
4) starts and runs but will die w/o warning while vehicle is in motion.

Early on 1-3 would manifest only upon restarting warm. Toward the end, item 4 began to be observed regularly with 1-3 being seen for warm or cold starts.

An interesting observation was made but failed to be understood in the context of the observed problem. Normal behavior for the tachometer is to 'pop-up' indicating the current engine speed following a successful start and release of the key. When the tachometer failed to respond following start and return of the key, condition 3 was always observed.

OBD II system was interrogated using Auterra Diagnostic Module. It was important to note that OBD II never reported a stored code (at least none persisting longer than the next start, successful or not). Why was this? Consideration was made of each of the many devices dealing with engine maintainence. Nearly all of the on-board devices which might have been suspect, should they fail, would generate a code and upon failure OBD II would revert to default setting or seek the information via redundancy to allow continued operation as opposed total shutdown.

After a few wiring checks and some reflection it was considered that perhaps a code was not stored because the problem was not one which the vehicle considered to be a device failure (i.e. turning off the vehicle is not an event that would not store a code as it is considered normal operation). This consideration led me to suspect a possible failure of the ignition switch or one of its leads/connections.

Hope this helps.

Mark

Personal plug: The author has held certifications in 7 of 8 ASE automotive specialties but subsequently 'traded' these for a B.S. and M.S. in Inorganic Chemistry. If anyone reading this is interested in employing a strong analytical thinker with a formidable mechanical and scientific aptitude please contact at: mbiscott(at)att(dot)net. Thanks.

[rooptroop]

Great info, but how do you get the ignition switch out?

[crossroads]

Ahh, slight of hand a couple of abracadabras.

Seriously. While a dash-mounted switch a generally easier to remove than a steering column mounted one, due to the numerous safety systems on-board this vehicle (theft deterents, air-bags) anyone ready to attempt it would be advised to find a trusted repair manual and study the affected systems and make a plan of removal. I am not kidding.

It appears at last look (8/03) Hayes does not publish a repair manual for the Intrigue body-style line (Century, Lumina, Grand Prix). They do offer one for the Alero which I understand to be a 'smaller version' of the Intrigue (e.g. compare the Grand Prix vs. Grand Am) as some of the systems are very similar. Outside of the factory manual you should find Chilton adequate. Chilton had an inadequate (generic) circuit diagram of the ignition system so I had to trace the circuitry to understand the switch wiring but the description of removal and system precautions were well written making removal and replacement quite straightforward.

Once you have decided to remove the switch you may prefer to spend the $130-150 for a new switch as opposed to disassembly and cleaning. While the switch and lock cylinder are integrated, they may be removed from one another so re-keying the vehicle is unnecessary The greatest difficulty I encountered was maniuplating the switch in the dash 'cage' so as to facilitate removal from and reinstallation into the dash via the instrument cluster 'hole'.

Mark