Low oil light - (Need Q45 tech to answer)

[david_k_powers]

New member here (but have been reading the site for over 4 years). Just bought my second Q (1996 w/64k from lol).

I'm in a dispute with Texaco Express Lube about an improper oil change. I ended up driving the car about 1 mile with the low oil light on, and feel that this may have damaged the engine.

Texaco Express Lube advises that the Q45 has a low oil cut off switch that shuts the motor off automatically if oil level is so low it will hurt the engine.

Is this correct?

Thanks

[Q451990]

I'm not Q45Tech, but I can tell you that what they're saying about the engine shutting down due to low oil pressure is absolutely not correct. The idiot light is controled by the ground from the oil pressure switch - and that's all the car does. Honestly I have never heard of a car that will shut down with low oil pressure as a precaution. The Q does not have any mechanism to measure oil level - only pressure. I would ask them to prove to you with some sort of written documentation that your car has this feature. Pages from the FSM, etc. I guarantee they can't back up their bull****.

You were driving with low oil pressure... probably due to low/no oil. You almost certainly did some sort of engine damage - the extent of which may or may not be evident for several months or years. I think it's lawyer time.

Be sure to document evey conversation, dates, times, people you talked to... You need a good paper trail to follow in case your engine is toast due to their incompetence!

Every time I read these threads - I remember why I change my own oil. It would probably be cheaper to have someone else do it given the value of my time - but I don't trust anyone else - for the exception of Byron at T3 (3.5 hours away) or one of my best buddies from school who's an ASE certified master tech. and lives over an hour away.

Good luck!

Heath

[Q45tech]

As far as I know no automobile on Earth has such a switch.

The Q ecu knows nothing about oil level or pressure the light comes on when oil pressure drops below ~~3 psi.

The FSM warns that the minimum oil pressure should be 14 psi.

Obviously a few seconds of no/low oil pressure occurs with each oil change.

I'm not sure a mile would cause severe damage depending on lots of factors.....................how many seconds was the engine running and what was peak rpm.

The only way to know for sure would be to disassemble the engine bearings and wrist pins and examine them.

At the minimum I would have a independent technican connect an accurate oil psi gauge and measure the hottest idle pressure.

Worst case will occur when it is 100F outside, drive for 15 minutes then read in drive, brake on at 650 rpm.

[DrewQ45]

Were you able to determine how much oil was actually in it? Was it registering on the dipstick at all? If you had SOME oil in it and only drove a mile, I doubt if much (if any) damage would have been done. A mile is a very short distance, barely enough for the engine to reach normal operating temp. Even a thin film of oil in the cylinder would have protected it adequately given the short space of time.

Heath, you are so right though... nothing like doing it yourself.

...Drew...

[maxnix]

Just one question: Why Texaco Lube Express?

[bullittandy]

Just one question: Why Texaco Lube Express?

Way to rub salt into the guy's wound.

[elwesso]

Certainly there had to be SOME measurable damage done just because driving sans lubrication = wear.

Wether or not it created actual sustainable damage is another question... I would, like Tech said, have the oil pressure measured and if your still above the 14PSI mark with brand new oil, then your motor is probably still ok.

Irks me that people treat the HIGH PERFORMANCE RACING MOTORS this way. You should have to swipe a card before you open the hood of one of these things, so the car know's your qualified.

[david_k_powers]

Thanks for the info.

So.... an oil pressure reading will indicate engine damage. How so?

[elwesso]

if you have lower than 14PSI oil pressure then the motor has sustained some damage... Drive on highway for 15-20 mins with AC on then idle with foot on brake in drive while checking oil pressure.

What your looking for is that WORST CASE you do not drop below 14. If your only a couple pounds away (say 12) worst case you could probably switch to a slightly thicker oil and may be OK, but if your more than 1-2 then you have sustained engine damage.

[david_k_powers]

Great info. Thanks ELWESSO, Q45TECH, DREWQ45 and Q451990. I'll get the oil pressure test done and let you all know the outcome.

[Haitian_King]

Wait. The Q engine is a high performance racing engine? Wow.

I feel so much cooler.

BTW, I smoked some Mustang a couple days ago. He thought he was so cool. Not anymore.

[Q45tech]

Unfortunately psi will only show bearing wear not RING or wrist pin or cam surface problems NOR Rod bearing problems just crank shaft bearing wear.

The problem with a used engine is you do not have before numbers on every surface................wear could have already been there.

[xerexabante]

Try fixing a Jaguar Qtech. Jags have them.

[Q451990]

Try fixing a Jaguar Qtech. Jags have them.

Interesting! I assume you're talking about a low oil level engine cut-off feature? I have always thought that Ford developed the low oil warning idiot light because they need it with their published 1qt/800 mile consumption is "normal" BS - maybe their association with Jaguar has rubbed off

Heath

[maxnix]

Try fixing a Jaguar Qtech. Jags have them.

Have what? Engines? Shutoffs?

[xerexabante]

Yes older pre 1987 xj6 at least have them. trust me, i had one. and one of my buddies had this problem.

[maxnix]

Yes older pre 1987 xj6 at least have them.

What be "them"?