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2003 Maxim - Failing Smog + Bad Repairs?

Hi there! I have a 2003 Nissan Maxima with about 190,000 miles on it. It recently failed smog due to blue smoke coming out of the exhaust pipe.
When I took the car into the mechanic, he stated his smog machine was down, but they could take a look, do an oil consumption test, and see what could be causing the issue.
They did an oil change, replaced oil gasket covers, spark plugs, spark plug tubes, and brake fluid. Each time they found something that needed to be fixed or replaced, they would call and explain how the oil was leaking from the gasket covers, onto the spark plugs, and they thought it was causing the blue smoke.
Fast forward a week… I took the car into smog after running about 300 miles on my car so the oil could burn off (as informed by the shop, this happens between 300-600 miles). It failed again, and the of shop argued they were dishonest and didn’t fix anything related to smoke coming out of the tailpipe.
We’re stuck in a we say-they say-they say situation, and my knowledge is extremely limited… Well, with anything related to cars. I’d love some expert opinions on whether the shop was telling the truth, we should wait until after 600 miles to smog the car again, take it to a different mechanic, etc.
The shop is arguing that they made the fixes, and trying to backtrack saying none of this is related to the smog diagnostic and they supposedly told me that upfront. Ultimately, I just want to fix my car ASAP and get the smog done! Help!

they did a good stuff, but not anyhow connected to the smoke from tailpipe

“blue smoke coming from tail-pipe” is pretty much an indication you either have to replace valve seals or you have a worn engine (piston rings worn), which both will call for much more expense than replacing spark plugs/gaskets or brake fluid (how is BRAKE FLUID connected to the smoke??)


Thank you for the feedback!
At this point we’ve sunk 2 grand into this (half parts half labor). We’ve tried to make a large point to them that I specifically handed the smog papers stating why it failed and possible fixes. Not sure where the other things came from, but again, I’m pretty ignorant in this area.
Do you have an idea of the fair market price for the fix you’re suggesting? I can’t remember exactly, but I think the of techs said the same thing (after the mechanics made their changes… Ugh!).

sorry, can not comment on this, as I’m strict DIY-er

AFAIK this site had both mechanics ratings (last link up top) and somewhere it had “fair price estimator for common repairs”, but I’ve never used these

I’m afraid that remaining value in 2003 Maxima is such that major engine repairs might warrant swapping the car :frowning:

get an idea from mechanics if it is valve seals or piston rings problem

if this is about valve seals, it probably can still be done within a reasonable budget, but for piston rings you are pretty much talking about junk-yard or swapping the engine

compression test will likely pinpoint a root cause and help in making this decision

I agree with what @andriy.fomenko posted. Nothing the shop did would stop the car from smoking out the tailpipe.

This old girl is worn out and is need of a rebuilt or used engine to pass smog. As a “hail mary” to make this car smoke less so it can pass smog, you might want to give a try to a product like Engine Restore or Rislone Ring Seal or similar products that claim they can stop the smoking and help you pass smog checks. You can buy a number of these products from any auto parts store and add it to the oil. They are a cheap fix but it will likely only get you past THIS E-check. It could buy you some time. Sorry.

I second that advise, both products will do some limited improvement on sealing oil from your exhaust

you might want to get one grade higher on engine oil too: AFAIK your Maxima requires 5W30 oil, so go with 10W40 or 15W40: it will smoke less since oil is more thick, you will see slight decrease in MPG, but not dramatic

Don’t go with a thicker oil.

All this does is wears the rings faster causing increased oil burning.



even my 2012 Altima has 5w30 as recommended and 10w40 as one of possible uses

why would it “wear the rings faster” ?
what is the physics of the process?

I hope you’re trying to get some of your money back

I think you mean the valve cover gaskets, a common place to get oil leaks. I’ve had to fix oil leaks there on my Corolla 3 or 4 times over the years. But oil leaks from the valve covers leak oil onto the outside of the engine, and wouldn’t cause an blue smoke out of the tailpipe. It’s theoretically possible the oil could get on the spark plug connectors and cause a misfire and poor idling and generally poor drivability, but even that wouldn’t cause blue smoke out the tailpipe. Getting the valve cover leak fixed makes sense tho, if only b/c leaks there make a mess of the engine compartment, which then causes any future diagnosis’s to be more difficult, and any future repairs, likewise.

I should say I was taken a bit aback by the statement “failed smog due to blue smoke”. Here in Calif at least that wouldn’t be a cause to fail a smog test. If fact that might make it possible to pass a smog test you otherwise couldn’t. Smog shops won’t test a car with a lot of oil in the exhaust as it damages their equipment, so they give you an automatic pass. Seems illogical right? Remember, we’re talking about California … :wink:

Yes, it would

In Nevada if a vehicle is smoking and might jeopardize the filters in the test equipment during a tail pipe test the test can be aborted, the vehicle fails. A smoking vehicle is always a failure.



Sorry, @Tester, but this is just a general talk, no hard facts to substantiate the claim.

Getting back to Owner Manual:

Page 9-6:

Now, given that Nissan has no special reservations “xxW40 oil can be used if no other substitutes available with replacement ASAP” or such… you get the point.

This old beaten car will definitely benefit from 10W40 or 15W40 thickness oil

Here’s the owners manual for your vehicle.

On chapter 9, page 2, is the recommendation for motor oil. It just lists 5W 30. Nowhere is it recommended that 10W 40 oil be used.

The reason? Your engine has variable valve timing. And oil viscosity effects variable valve timing.

To me, that puts your truthfulness in question.


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Sorry if I did not make it clear, but original questions was about 2003 Maxima, so the discussion is on what oil to pour into THAT nearly-dead engine.
That engine is happy to eat 10W40 as well as any xxW40 one would care to put there with reasonable cold temperature rating, i.e. 15W40, which can be bought in any store.

I’m not advocating for 10W40 to be used in 2012 Altima, although I made a mistake of implying it can eat it without checking first, which came from assumption from my older Subarus, listing xxW40 as one of possible choices.

My another car is 2006 Pathfinder, which once again recommends 5W30, but 10W30 and 10W40 are other recommended ratings, for temperature ranges similar to OP’ Maxima, BTW they share engine design, but not a displacement size.

The bottom line is: getting one tier UP on oil viscosity will not be a factor to ruin your engine and/or piston rings.
I might SUSPECT that going one or more tiers DOWN on viscosity MIGHT actually damage it, as oil film clearance will definitely be reduced, no magic.

Oh, Mr. @Tester, I missed that part at first, so let me ask you to give any substantive argument into HOW oil viscosity will affect timing, can you? You already missed the actual original point on “All this does is wears the rings faster causing increased oil burning.”

Read and learn.


20W50 in place of 5W30 is a little bit extreme by any count, but still an illustration that it indeed might affect valve timing controls.

In any case, OP’ Maxima is not under question here, but my 2012 Altima was a bad example apparently to make the point.

I went to check 2007 (beginning of model line ending with 2012) and they all are on 5W30, while prior model year had 10W40 in list of recommended viscosities, so I’ve got something new learned from this, but I would never really imagine a sane person to use two grades thicker oil to compare to recommended

I don’t think it used to be that way. But this document below seems to indicate a visible smoke test has been added to the routine in Calif. So your are right db4690, visible smoke indeed does appear to be a valid reason they can fail you in California. They just do it by eyesight is all, to prevent damaging their equipment.

"The new smoke test … "