Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Smoke at Startup & Check Engine Light

My wife has a 2013 Nissan Quest with 60,000 miles on it which yesterday started smoking on startup and the check engine light came on. It is overdue on the oil change by 9k and when I checked the dip stick it is caked with sludgy oil. When it starts it puts out a cloud of blue smoke for about 15-20 seconds and then stops. I only drove it the distance from the house to the dealer (about 15 mi) and it ran fine both in town and on the highway. No smoke, no hesitation, normal amount of power, no strange noises.

The dealer ran the code and came up with errors on both valve solenoids (its a V6). They said its been driven too far without an oil change and would diagnose it no further. The only option, according to them is to replace the motor. Also, they changed the oil and said it continued to smoke.

So, obviously it was let go WAY too long between oil changes but there was no low pressure light, no over heating, no other indicators of an issue. Also, 14k between changes while not ideal by any stretch should not destroy the motor…

I am picking it up from the dealer tomorrow and don’t really know where to go from there with it.


On what do you base this conclusion?

You might get away with that on synthetic, but if you’re neglecting it this badly I’m guessing you’re not springing for synthetic.

This is an expensive lesson; Cars require maintenance and if you don’t maintain them it will cost you a lot of money. While I would definitely get a second opinion before moving forward, I wouldn’t be at all surprised if the sludge were bad enough that replacing the engine would be cheaper than the alternative, which would be to take the engine apart and clean everything. Especially since if you went this long between oil changes this time, you probably didn’t get it changed regularly beforehand either.

If there’s that much sludge in the engine, the oil drain-back holes in the heads may be restricted.

I’d ask the dealer to remove the valve covers to make sure this isn’t the case. And if it is, remove the sludge from the holes.

Then I would do a few oil/filter changes along with Sea Foam added to try to remove any sludge.


I seriously doubt if the Nissan maintenance schedule states that 14k is acceptable mileage between oil changes, but the overriding issue–at least as far as I am concerned–is the amount of elapsed time that took place between oil changes.

Going 6 months between oil changes is usually the longest interval that manufacturers approve of. How many months elapsed while those 14k miles were accumulated, and how much local, short-trip driving was involved? When an engine is used for a lot of that type of service, the oil never gets hot enough to burn-off water vapor and other pollutants, and that results in oil sludging. As a result of that reality, 6 month oil change intervals should be adhered-to if you want to avoid oil sludging.

You could try giving this engine a little TLC and prolong its life. This may or may not work but no matter what odds are you have greatly reduced the life of this engine.

1 Like

So other seafoam, which I will do, what other actions should I take to prolong the remaining life of this motor?

Yes, synthetic was used on the last oil change about 8 mo ago. Its gone through mostly highway ‘cruise control’ driving.

Just be sure that the Seafoam is used just before the oil is drained and changed.
Seafoam is a very good solvent, but it is not a lubricant, and it is a good idea to run the engine for no more than… maybe… 30 minutes after adding the Seafoam, and before changing the oil.

Sea Foam consists of a stoddard solvent. isopropyl alcohol, and a highly refined oil.


The variable valve timing (VVT) solenoids require clean oil of the proper viscosity to function properly. Based on your description of what you found on the dipstick, they clearly didn’t get it.

I would suggest adding Seafoam to the oil and letting run at idle for 10 minutes before changing the oil and the filter. Then see what happens. Use synthetic and go from there.

If your engine is REALLY sludged, Seafoam can release too much crud all at once. It is a great solvent which can be a bad thing if it breaks something loose that then plugs something else. You probably don’t have a lot to lose here though.

It’s very apparent to me to me that nobody knows anything about Sea Foam, or the recommendations on how it should be used.

And yet, they chime in.


Variable valve timing (VVT)equipped engines (as this car seems to have) is very sensitive to the cleanliness of the engine oil. Much more than engine designs of the past without VVT. The advice above to remove the valve covers and de-sludge-ing the drain back holes is worth a go. Beyond that, continue to use synthetic oil, changing it and the oem oil filter out every 1,000 miles, until you do that 5 times in a row. Synthetic oil is a very good internal engine cleaner itself, and 5,000 miles of that treatment is about the best you can do. If that doesn’t cure or at least reduce these symptoms to an acceptable level, a replacement engine is the next step.

If your car uses a pcv valve, cleaning the entire pcv system (replace the valve and clean all the tubing) is worth a shot too. A stuck pcv valve can cause lots of exhaust smoke too.