Sludge in a infinity 2008 infinity EX 35

Hi ,

I have a sludge problem with this a 2008 infinity EX 35 .

The car was initially stalling and had been in service at the dealership several times .

Error codes were present and they didnt know what the cause was . They replace spark plugs and tried to find a bandaid rather find the cause ,

Now they are claimimg they cant do anything for the sludge issue and blaming it on poor maintenance … the oil was changed ever 3000 . they have the records of this also .

They talked about flushing the engine , but stated it doesnt work

Is this vehicle prone to sludge . Its onlyonly running on 5 cylinders instead of 6 per dealer . .Does everyone have any

suggestions or solutions ?

woul;d appreciate it .


If you have documentation of 3000 mile oil changes, I can’t see how they could claim it’s maintenance-related. This should be 100% in their hands to fix completely. You might want to send them a letter explaining this, with copies of your maintenance receipts, registered mail. It sounds like you’ll need a very clear record if they continue to be uncooperative.

The Nissan V-6 engines are NOT known for being sludge prone.
Even less so with a 3k mile oil change interval.

Tell them you want proof of sludge in the engine, i.e. a couple of pictures of the engine with the valve covers off.

How long does it normally take you to put on the 3k miles before your oil change?
How many miles are on your SUV?

Also, the valve covers are known to leak oil at the spark plug tubes on this engine, and when they do, the oil shorts out the spark plug, which then makes the car run on 5 cylinders instead of all 6. Usually this happens in one of the two rear cylinders, and is a COMMON issue with Infiniti cars and SUV’s with the 3.5 V-6.

The worst part is that you can’t just buy the replacement o-rings for the spark plug tube on the valve cover, they want to sell you the whole valve cover kit, which costs quite a bit from Nissan/Infiniti.

Are you still within the power train warranty (I believe 70k miles on Infiniti’s), if so, tell them that they HAVE to replace the valve cover gasket if that is the cause of the missing cylinder.


Nissan/Infiniti is famous for being uncooperative when it comes to warranty claims.
They are just ahead of VW and Hyundai for unhappy dealings with the service department, and the corporate offices for North America.


I Wonder What Prompted Nissan (?) ( Is That Who Makes Infinity ?) To Start Recommending “Nissan Ester Oil” engine oil in some of their 2008 - 2009 engines ?


The ester oil was supposedly to take care of excessive valve noise at high (above 6500) rpms.
It didn’t.

But it was a great way for Nissan/Infiniti to start charging owners $12 a quart for poor quality engine oil.


There’s a lot of info missing. How many miles on the engine, what codes exist, whether the car was stalling at idle only, any CEL on, compression test done, etc, etc.
The only way sludge should cause an engine miss would be if the piston rings on that cylinder sludged or coked up and the compression dropped to a very low level.
I’m having a hard time seeing that happening on an '08 with regular oil changes.

What they’re telling you and doing is a bit suspect at this point. Spark plugs are a wild, and bad, guess.
Flushing the engine could fall in line with the sludged/coked piston ring thing but one would have to assume they ran a compression test during all of this.

Nissan/Infiniti is famous for being uncooperative when it comes to warranty claims.

Owned several Nissan’s and NEVER EVER had a problem with warranty claims. Usually when there’s a problem with warranty claims it’s the Franchised Dealer…NOT the manufacturer. I do know Nissan Dealer in NH that is notorious for this and extremely bad service…That’s why I bought my Pathfinder from another dealer 20 miles farther north…and when I did have to make a warranty claim…NO PROBLEM WHAT-SO-EVER. Even had a free loaner for the day.