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Engine Sludge Causing Smoking on Starting - Can it Be Fixed?

I have a 2014 Nissan Murano and have changed the oil several times, but maybe not exactly at 5000 miles each time. It now has about 40,000 miles and started smoking when it is started (white oil type smoke) which stops after it runs for a short while. I took it to one Nissan dealer and they said they could find nothing wrong - told me to change the oil 3 times at about 3000 miles. This didn’t help, so I took it to another Nissan dealer who looked further and said there was sludge in the engine and their only solution was a new engine for $10,000 and the power train warranty was void because they surmised I hadn’t changed the oil often enough. Is this likely with a car this new? What should I do - is there a way to fix this without putting in a new engine? Who would you recommend to look at it for me? If I do need a new engine - who should I get to do that for me? Any help or advice you can give would really be appreciated. Thanks! --Jack

White, or blue smoke? White is coolant, blue is oil.

Do you have receipts for your oil changes? How many times would you say you’ve changed the oil since you’ve bought it?

As for the warranty being void, the onus is on them to prove that your neglect broke the engine - this means they’re going to have to do more than just say “we found sludge,” they’re going to have to document that sludge.

Take the oil cap off and shine a light down in there. If it’s as sludgy as they claim, there should be big, tarry lumps of sludge clearly visible in there, like this:

A sludgy engine can damage gaskets, which could cause problems, but unless you’ve been shockingly neglectful (which, I don’t know - a lot of people are, and I don’t know anything about you) it shouldn’t have killed a 3 year old car.

All that said, if you’ve changed your oil even twice, since new, you shouldn’t have enough sludge built up yet to cause problems.

Please post the exact mileage and date for each oil change that you did.

Did you purchase this vehicle new ? If not about how many miles on it when you got it ?

Additionally, we need to know the conditions under which the vehicle is typically driven (mostly low-speed local driving, mostly highway driving, a mixture of the two, a lot of idling, etc) , and we need to know how often between oil changes the OP checked the oil, and what he found each time that he checked the dipstick.
While 40k miles does seem to be very early for a damaging accumulation of oil sludge, the way that the vehicle has been operated does play a role in this process, so we need to know that.

Engine sludge seems to have become a convenient GET OUT OF JAIL FREE card for dealerships and manufacturers. Isn’t that great…

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First I have to ask; have you been checking the level of the oil between changes?
Also, how FAR above the recommended oil change mileage have you been driving it? 6,000 miles? 7,000 miles? 10,000 miles?

This diagnosis sounds awful fishy to me. There’s no way I’d accept it without independent verification. An independent shop can simply remove a valvecover to determine if there’s sludge buildup. Ask them to allow you to take photos, lots of photos, to prove that there’s no sludge. Note that you’ll have to pay for the shop to do this, but if you end up in court and win you can recoup the costs.

Legally this is true, but the way it actually works is that they simply deny the warranty claim with a simple statement on the shop order and the onus is on you to prove them wrong… generally in court. It stinks, I know, but that’s the reality.

When an oil sludge engine comes in normally a valve cover is removed and pictures are taken of the engines condition. Next the customer is asked to bring their oil change records in for proof of maintenance.

You can take your vehicle to another shop to challenge the findings but the sludge probably has already been documented, just ask the dealer to show you what they found.

The dealer techs do not want to fool with a damaged engine but you may find an independent repair shop willing to try to repair this engine.

I bet ajackwad is a friend of the troll whose motor caught fire.

It ends with wms, not wad. I’ll give him/her the benefit of the doubt unless he/she proves otherwise.

If your Murano has the 2.5L 4 cylinder, they are notorious for blown head gaskets. White smoke indicates coolant, not oil and that is consistent with a blown head gasket. But you are just out of warranty, but maybe if you call Nissan CSR (number can be found in your owners manual), they might pay for some/most of it.

Unless you used some real crap oil, your engine should not be sludged up. When you have sludge bad enough to cause oil to burn, it is the drain back holes that are blocked up. They can be easily cleared. But when they get plugged up, you burn oil all the time, not just at start up. Oil burning at start up is usually due to valve stem seals, again you should not be having that issue on a vehicle of your age and miles, and it would be blue smoke, not white.

Are you checking your coolant level? If not, do so. Are you loosing coolant?

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Good things to check for above. Another idea, white smoke out the exhaust pipe right after starting the engine is normal in cold weather. The colder it is, the more white smoke. My truck smokes like a chimney with white smoke first start in cold weather. Nothing wrong w/it. If the white smoke (which is really just steam, a normal product from the combustion of gasoline) goes away in a couple minutes, this may not require anything at all be done. One test for this would be to keep the car in a heated garage overnight, heated to say at least 65 degrees. If there’s little to no white smoke on the first start of the day at 65 degrees, like I say, nothing needs to be done. Just steam. It’s normal.

Brown or black smoke right after starting the engine often indicates faulty valve stem seals. But if the black or brown smoke isn’t all that much and goes away within a minute or two, many owners would just live w/it. Replacing the valve stem seals for that wouldn’t yield much bang for the buck. Check the oil level a little more often is all.

I’d be surprised if you had a sludge problem on a 2 year old vehicle. Especially if you’ve changed the oil & filter at least once a year and at least once every 10-15,000 miles. And used the correct spec oil for the change. So if you’ve changed the oil at least twice and drive about the normal number of miles most of us do, seems dubious to have a sludge problem. Yu’d want to get that independently tested by another shop at the minimum before taking any expensive-sounding action.

Not saying 15K oil change intervals is a good idea for the long term life of your engine btw.

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[quote=“keith, post:11, topic:97460, full:true”]
If your Murano has the 2.5L 4 cylinder, they are notorious for blown head gaskets.[/quote]The Murano only comes with a 3.5L V6.

You can replace that engine with a low mileage salvage yard engine for a fraction of $10,000, but there are a lot of options to try before giving up on the engine.

First, verify that it is blueish smoke (oil) and not white water vapor. If it is oil smoke, it may be that you notice it more after startup because the catalyst helps burn the oil smoke up when it gets warm. Thoroughly clean out the crankcase ventilation system. Replace the PCV. Clean the oil mist eliminator, which on a Nissan is probably attached (permanently) to the inside of the valve cover. Don’t be bashful about drilling the drain holes a bit larger in that mist eliminator.

There are no end to the types of snake oil you can add to your oil to help clean out sludge. Drive it hard and change oil often. Marvel Mystery Oil, ATF, and Seafoam come immediately to mind. Some cars burn oil because the oil rings get stuck in the piston ring grooves. Those snake oils just might free them. Remember that if your final option is engine replacement, you have nothing to loose by pouring snake oil into it to try to clear the sludge.


Jack I have the same exact problem with my 2014 Nissan Murano. Have been battling them for 4 months. I bought it “certified pre owned” with 30000 miles on it. I changed the oil 4 times over the year since I bought it. I was convinced to buy an extended warranty for 120000 miles of coverage. Denied repair under warranty. Blaming me for lack of maintenance which is incorrect. The previous owner was allegedly a car rental place, but I’ve been shown no service records. I didn’t have receipts for the oil and oil filters i bought from Walmart over the past year so they’re denying on the assumption I didn’t change it. It’s been ongoing battle. Lots of BS. But I’m continuing to battle. Maybe there is an issue with this model. Strength in numbers. Contact me if you want to exchange information of our dealings with Nissan.

I understand your frustration @Gr8rbimanone but I don’t think you can expect Nissan to cover an engine warranty problem when you are not able to provide evidence that the required routine servicing has been performed. When purchasing a used car, besides asking your own shop to do a pre-purchase inspection, part of the transaction is the owner providing the buyer the servicing records. If the records are not available, the buyer might still want to buy the vehicle, but would probably expect a sizeable discount on the price. I don’t see anything about a design problem w/this engine causing oil sludge, so I’m skeptical about this being a known issue. I expect you just got a little bad luck and perhaps not being quite as diligent as required during your purchasing transaction. If there is some sludge buildup, removing it is usually quite do-able in most cases, but may be somewhat time-consuming and therefore costly.

. Contacting people through a internet forum where real names are not used is a waste of time. Your main dispute is with the extended warranty company.

The reason denials are so easily made is because the car manufacturers and warranty insurers have heard it all. Even someone who has neglected a vehicle all to hell will swear on a 10 foot tall pile of Bibles they maintained it religiously.

I’m sure your car has been maintained well but without records you’re up the creek. If you read the terms of the warranty you will find it spelled out quite clearly.

As for extended warranties, ti’s tougher to take advantage of those than an original factory warranty as the fine print is lengthier and there are more hoops to jump through.

A warranty is essentially a contract, and enforcing it requires that certain requirements be met–and those requirements include documentation of maintenance. Without documentation, it is essentially impossible to get them to comply with the terms of the warranty.

The typical extended warranty has so many weasel clauses built into its verbiage that it can be very difficult to get the warranty company to comply with it–even if you do have documentation of maintenance. Additionally, these companies have a disturbing tendency to go out of business, taking your money with them.

The only extended warranties that are worth the paper they are printed on are the extended warranties offered by the vehicle manufacturer itself.


My brother bought a used car from dealer. He was offered a warranty by 3rd party company and had 30 days to accept. On day 28 his motor developed a knock. He called warranty co and told them of issue and said they would warranty motor if he overnighted check for warranty. Which was a lot less than new motor. He got a new motor.