3.5 engine knock

[daisley]

My '01 QX4 with the 3.5 litre engine has fairly loud piston slap when cold. On initially asking the dealer about this, they said they had never heard of this problem with these engines. However, after hearing the noise first-hand, they then commented "oh, thats normal, they all do that".I'm thinking this engine is going to grenade. Has anyone else had piston slap issues with these engines?its only got 83,000 miles (132,000 km), and I'm really disappointed with this vehicle. I think an engine should last longer than this.

[Q451990]

Have them start up some other vehicles on the lot that have been sitting until cold and show you the noise. If they all do it, then you're probably OK. Did the noise just develop? How long have you owned your QX4? Are you sure it's piston slap? It could be a lasy lifter, leaky chain tensioner, etc.

My Q is super quiet at start-up unless it sits for several weeks (then some rattles) - but my truck has a lot of start-up clatter. Supposedly it's chain noise from tensioners that bleed down. In any case it's a very common issue and one that no one has resolved, at least for long...

Heath

[3Q Jay]

i'm no expert, but i have owned two vq series cars. is the 3.5 in your qx4 the vq35de? if so, is the 'slap' you refer just for the first second or two at cold start up? my vq30 [95 max] did this about 25% of the time. I believe it was the chain tensioners oiling up/purging. the G35 has only done this twice in 33 months. only other 'slap' i've experienced is a soft knock when warm at 900-1100 rpm when under a small load. both engines started doing that at about 20k mi. i've not heard of a normally aspirated vq expiring...although i'd bet someone has blown one.

[daisley]

I assumed it was piston slap causing the clank-clank-clank noise. It does it for about the first 5-6 minutes after a cold start, and only under load. A lifter would tap all the time, whether under load or not. Chain noise is more of a rattle, this is a definite clank (light knock). Yesterday the dealer finally heard it from a cold start, and verified it is definitely piston slap. I've had piston slap in older engines, with high miles, but I'm really disenchanted with my Infiniti at this low mileage.

[maxnix]

I assumed it was piston slap causing the clank-clank-clank noise. It does it for about the first 5-6 minutes after a cold start, and only under load.

Why the wise owner will always bring engine up to operating temperature before subjecting it to load. Usually less than 5 minutes at idle form a cold start.

[Q451990]

But at 81K it shouldn't be an issue either way. Do you have service records of regular maintenence? I'd start pursuing some factory "goodwill" on this one. I assume the warranty has expired, but if you can document good service history - you may be able to get some assistance. If you didn't buy the car new, try to get a copy of the Infiniti service records by having the dealer pull them by VIN. If you're lucky maybe the former owner complained about some engine noises before and you can document that the problem existed during the warranty.

I agree that it would be highly unusual to have this problem on any well maintained Nissan product at this mileage, but you may be in that 1-2% that got a lemon

Good luck!

Heath

[Jeff Williams]

Nissan replaced my 3.0 V6 engine in my 1995 Pick-up under a 100,000 mile warranty. The paperwork said it was a piston wrist pin, that would knock when extremely cold. It was not a big deal to me, so I drove the truck for a while, before I had it fixed. I thought they would rebuild the existing engine, but the dealership told me that they would put a factory refurbished engine in.

I got the warranty extension notice in the mail, and when I took the truck in, with 93,000 miles on it, they replaced the engine, no questions asked. Nissan even gave me a rental car for the 2 days they had the truck. I sold it at 139,000 miles, so I don't know how well the refurbished engine lasted.

I don't know of any similar problems with the 3.5 V6

[daisley]

Well, I only bought this thing 6 months ago, and have only put about 5000 miles on it. I really don't feel comfortable about keeping it for the long term, which was my original intention. I hate to unload it on some poor unsuspecting soul, but that's what the Infiniti dealer did to me!! Is there an oil additive which will mask the piston noise?Anybody wanna buy a QX4 ?

[Richard Petersen]

Sell it when the engine is very warm?