I drive a 2012 Infiniti M37x with close to 123k miles. Yesterday I was stopped at a red light, and as soon as the light turned green and I accelerated, the car suddenly lost power and seemed to start running noticeably roughly in general (sort of like a “rough idling” sensation). The temp gauge also shot all the way up, although I don’t think any sort of temp warning light came on. However, the Service Engine Soon (SES) light did come on.
Luckily, a large parking lot was to my immediate right, which I pulled over into and shut off the car. About 20 minutes later, I turned the car back on and the car seemed to have a rough start (more “rumbly” than usual) and the SES light immediately came on again; however, the temp gauge didn’t rise beyond where it usually sits whenever the car drives without issues.
The car seemed to idle a bit roughly, but I was able to gently drive maybe 20 feet forward without any noticeable issues. I didn’t want to risk trying to drive any further than that and turned the car back off.
The rough startup/idle sensation was similar to what I noticed about a year ago when the car had the issue of oil leaking down into the spark plugs and causing cylinders not to fire (all spark plugs were replaced when I got that fixed).
I have also had to have the MAF sensors replaced twice (noticed a severe loss of power both times they went bad), although I don’t recall issues with rough startup/idling either of the times the MAFs went bad.
Did not notice any smoke or fumes. No other warning lights came on aside from the SES light.
I’m going to have the car towed to a shop on Monday, but does anyone have any ideas as to what the issue might be?
No I did not (unfortunately I know very little about cars and have not done any checks on it). Is this an easy issue to check for by starting the car back up?
Once the engine warms-up, you should be able to see/hear the fan(s) running behind the radiator. But, I don’t suggest starting the engine at this point. Just let it sit until it can be towed to a mechanic’s shop.
I guess I will know for sure on Monday after the car has been towed somewhere. Really hoping it’s not something catastrophic like head gasket/engine failure.
A breached head gasket came to mind, but I didn’t want to mention extreme possibilities at this point.
But, since the engine is now cold, you could open the radiator cap to see if there is evidence of oil in the coolant, and you could pull the dipstick to see if there is any evidence of coolant in the oil. If there is coolant in the oil, it will look like a milkshake, sort of.
Thanks for the suggestion; I’ll see if I can get a ride to where the car is parked and check the oil and coolant.
Just out of curiosity, can I ask what makes you think it might be a breached head gasket? Also, if that does turn out to be the issue then is it safe to say that the car will need to have the engine replaced?
Regarding the topic of head gasket (or some other major engine-related) failure – I noticed that when I started the car back up after it had been parked for a few minutes, the temp gauge went to its usual “spot” that it typically holds steady at when it drives without issues.
Would this make the possibility of a head gasket issue any more or less likely?
Along with @VDCdriver, the first place my mind went was also head gasket. But I also hesitated to bring it up b/c there’s not much to go on.
However, with the cat out of the bag… a bad head gasket will often cause problems with engine compression. This means that the engine will run like crap (as yours did). And if the gasket breach includes a gap between the combustion chambers and the cooling jackets in the head, then hot exhaust gases will get blown into the coolant. That will mean pockets of really hot exhaust potentially hitting your coolant temp gauge - thus a spike on the temp gauge.
But I would not panic just yet. If this car has never overheated before, it would be odd for the head gasket to blow. Tho’ nothing is out of the question.
Appreciate the info. I mentioned in my previous post before this one that after I had turned off the car and let it sit for a few minutes, when I started the car again the temp gauge needle settled in its usual position on the gauge (I.e., where it tends to stay during problem-free driving).
Could this be at all significant with respect to what the issue could be? Or could there still be a head gasket failure even though the temp gauge needle stayed in its usual “spot” after I had turned the car back on?
Maybe but speculating from us on the web can’t make you feel better or worry more. You are just going to hope for a rsonable solution after the shop has done the diagnosis. Just tell them you need to approve any work after the diagnostic which will have a fee of course.
Quick update: a family member drove to where the car is parked and checked the oil for me (said they weren’t able to check the coolant). They didn’t take any pictures, but they said the oil looked like typical black oil (no “chocolate milkshake” appearance) and that it was at the mark on the dip stick.
Does this decrease the likelihood that it’s a head gasket failure? Or would it be more likely that oil would’ve leaked into the coolant (which they weren’t able to check) in the event of a head gasket failure anyways?
This is usually caused by insufficient coolant in the cooling system. If the engine became hot enough to run rough/misfire, the head gaskets are probably now leaking.
Out of all the damaged engine I have seen, perhaps 1% had oil in the coolant or coolant in the oil. Engine oil that in not polluted with coolant in not proof that the engine was not damage from overheating.
You need to take a closer look. Was the check engine light flashing? Is the cooling system empty? Foul odor from the cooling system?