IceY2K1

iTrader: (3)

I've had a weird starter screetch/timing chain slap sound once or twice awhile ago, so I know it's not that. However, after sitting all weekend, like always, when I started it up this morning a *HORRIBLE* knocking sound and rough idle/stumble occured. Knee jerk reaction was to shut it off immediately, so I did. I restarted, the knocking/stumbling continued, so shut it down. I checked the oil level, hard to read but plenty, so I started it again. It continued knocking for 15-20secs. maybe and seemed to be coming from the front back side of the engine, cylinder #1 if I had to guess. There seemed to be a small amount of smoke, but could have been condensation, not sure. It smoothed out after 30secs. or so and after driving to work it idled/reved/drove fine.

HISTORY....I've been thinking I've been down on power(thought about checking the VIAS), however I figured it was just in my head after all the broken VIAS threads. Also, about a week ago or so, after a WOT run or two, once I stopped there was a strong egg odor/cat burning smell. Also, flushed my power steering last weekend...don't think that matters though.

I know sitting for long periods of time allows the oil to really drain out of areas in the engine, so some noise/roughness is "normal". However, this HAS to be a sign that something is going awry inside the engine.

It is still under warranty, so that's not a concern except waiting for it to do it again and having it towed to the dealer so they can hear it on the 2nd/3rd start. I plan on getting an oil analysis this next oil change or maybe next week to see if SOMETHING can be found not within normal limits. If it does this again soon, it's going to the dealer for a compression test or other diagnosis. Also, thinking about checking the TB screws, but that's a VQ35 issue.

spiromax

Could one or more of your cats be fouled or damaged? I've heard of VQ30 precats being a problem spot. You say it sounds like it's coming from the "front back side of the engine," which makes no sense to me. The Maxima's precats are integrated into the exhaust manifolds, which are bolted to the engine, so that might be why the weird noise is coming from under the hood either in the front or rear. A fouled or damaged precat could also explain a loss of power.

This is a stab in the dark. I'm sure a smarter Maxima guru will come up with another explanation.

GBAUER

iTrader: (2)

I have the same problem after mine sits for a day or two (yes, I know that mine is a 3.5 and his is a 3.0). I also have noticed a lack of pwr over the last few months. I'll check the TB screws tonight, but I think it's the cat due to the smell. Incidentally, I used Seafoam this weekend to see if I could bring back some power. I noticed a little more pep in my state-of-the-art butt dyno, but, more importantly, the knock seems to have subsided a little. If I add Seafoam in the tank, does that increase the octain? If so, I think my timing may be off a couple of points and may actually need to be turned down some.

Also noticing a loss of oil over time (1-2 qts every 3k). I almost think that I'm burning oil and cloggin up the cats (blew smoke at a fellow .orger that was following me from the MIR meet in DC). Regardless, that doesn't explain the HARD knocking at start. I'm switching over to a heavier oil when I change it next to try to limit that. And, yes, I'll be rebuilding the engine soon to stop the blow-by.

GreenSeMax

wow, ice it almost sounds like your timing chain tensioners aren't engaging soon enough. The VQs have a hydraulic-type tensioner, which is why the chain slaps when you crank it in the morning, mine always does, but when the crank comes around the pressure builds up and it stops. My questions, what oil are you running, how many miles does the car have, and where exactly is the sound coming from? The front back side to me sounds like you meant passenger side rear of the motor, being that the engine faces the pass side. Other than having sticking chain tensioners, which would explain the smoke(inaccurate timing) and erratic noises, I can't think of much other that would cause this.

IceY2K1

iTrader: (3)

Yeah, passenger side/firewall, I'd guess cylinder #1.

Redline 10W-40 w/39,xxx.

The chain slap was only once, maybe twice, in the past year or so.

This noise was something clanking/banging like piston slap definitely not just a "sticky lifter" that hasn't got oil yet sound.

A bad precat that allowed a piece to get sucked back inside the engine like Sentras/VQ35s have might be a possibility.

Larrio Motors

iTrader: (23)

how many miles on the engine ice? your description sounds like what happens when you throw a new engine into a car and the chain tensioners are trying to get enough oil pressure to the timing chain so it keeps knocking.

and the rotten egg/bad smell after WOT runs happens with me also (although I think my cat is fine, not sure where the problem is from)

IceY2K1

iTrader: (3)

39,xxx miles.....

I've heard the chain slap sound before, however this was something completely different, I believe. The chain slap was a quick clunk/screetch sound IIRC, however this was a serious knocking/metal on metal thuding sound.

GreenSeMax

I'm baffled to be honest, I can't quite relate to the precat situation, because i only had them for a couple weeks, but i do know before i purchased the car it had the stock y replaced because it fouled..................food for thought............but all the same the old owner said it didn't make any noise, just smelled and lacked power. But all the same very well likely. My other thought would be a plugged fuel pickup, since we have no ext. filter, moisture in the lines from sitting, or just plain ****ty gas. I dunno i hope you figure it out man.

IceY2K1

iTrader: (3)

Yeah, I don't know what I can do other then wait for it to happen again and tow it to them to hear it. Or wait for it to get worse and die, so Nissan replaces it. However, even though I only have ~40K, the 5yr mark is ~8-months away.

I've heard that if you go over 5yr/60K, even with the extended warranty, they replace it with a used motor vs. a new one?

GBAUER

iTrader: (2)

Check your contract. I can't see how if you paid for the warranty that they can change it after the fact. Read the fine print.

I've never heard of the 3.5 pre-cats breaking apart and allowing pieces to get sucked into the block. You'd have to have a LOT of things go wrong to do that: the pre-cat would have to fail and break itself apart and the car would have to misfire otherwise it would go out the back, not try to exit through the intake. Like I said, I have a simular issue in my 3.5. Have you checked your timing? If not, it might be the place to start. Also, is it possible you could have a weak fuel pump that takes time to ramp up to speed? If you ran the engine too lean, the engine make detonate too soon causing the bang. The reason I brought up Seafoam was because it might lie in the fuel system rather than the cylinders, valves, cams, or crank-case. For $5, if it helps even a little, you've narrowed down the problem.

IceY2K1

iTrader: (3)

Just what I've heard here(BlackBirdVQ??) and on the net...basically under deceleration you get some reversion into the combustion chamber and if the precat is in little pieces it can be sucked in.

spiromax

I've heard of the VQ30 precats clogging/disintegrating, but I've never heard of material from them being sucked back into the combustion chamber. I remember the thread you're talking about. I brought up the precat problem on Nissan's QR25 engine (used in the B15 Sentra SE-R). Their precats disintegrate due to excessive heat exposure, and little bits get sucked back into the engine. Somebody here said that it's because the QR25 doesn't have a conventional EGR system, but it uses aggressive valve overlap to draw some exhaust gas back into the cylinders instead. I don't know if this is true.

Anyway, your precats could be damaged somehow (possibly due to heat), and they might be disintegrating, but I don't think pieces would get sucked into your VQ30 the same way they do on the QR25. It could still be causing a rattle or metal-on-metal knocking, and if the pieces are gathering up and collecting against the parts of the cat that are still intact, then it could explain the power loss, especially as you go higher in RPM.

GreenSeMax

My best advice is to induce it if you can again, let it sit, and then pinpoint on the car exactly where it's coming from. From experience you can often feel vibration better than hear it on the motor, and if it's cold you can touch the exhaust for a minute or so. About the warranty.........at 121k i can't relate, but that sounds bogus. If anything maybe a remanufactured motor, but not used. Hell you can pick up VQ30DE-Ks for like 400-800 with less than 60k on them around CT. Even if it was the case, I'd offer to pay the diff to get a new one over reman anyway.......just piece of mind, instead of piece of ****.

IceY2K1

iTrader: (3)

Pretty sure it was the Sentras and VQ35s, not VQ30s, but since at least on 2001s(cali 2000s?) and the VQ35s, we don't have the "convential" EGR...maybe we're in the same boat?

Anyways, the rotten egg smell could have been anything, I didn't mean to muddy the water with that.

IceY2K1

iTrader: (3)

I did...it was coming from cylinder #1 area. You could FEEL the knocking and visably see the motor shaking almost like a misfire, but with a LOUD knocking/piston slap metal-on-metal sound.

I'll check my warranty, but if it was a used motor, I'd dump the car.

GBAUER

iTrader: (2)

Could it have been a misfire that the computer didn't read for some reason? I'd also check the plugs and coils as well. May have had a CES light and not known it due to the computer cylcing for the first 15 seconds. If you have an Autozone around, you may want to see if there's any codes stored. Since you say the engine was knocking hard and rocking back and fourth, it sounds more like a cylinder isn't firing than anything else to me.

BTW: had that too. Same deal. Code didn't show after the incident until it was pulled from the memory. In fact, at this point if it's gonna happen to a VQ35, I've most likely had it happen to me. 108k on my '03 se.

Larrio Motors

iTrader: (23)

the sentras and some VQ35 altimas at my local dealer with the precat problems are not getting brand new motors but refurbished ones

IceY2K1

iTrader: (3)

This wasn't a misfire. Definitely not.

GBAUER

iTrader: (2)

In that case, time to tear it down, invest 7k and convert it to a 4.3 liter.

IceY2K1

iTrader: (3)

IF I did that, it would be in a G...

Darton liners w/VQ35 crank in a VQ30 would be 3.8L-4.0L depending on how much you bore the liners for a lot less.

GBAUER

iTrader: (2)

I'm going to need to talk to you when i get this thing paid off. by that time, it'll have 200k on it, so it'll be due for a rebuild regardless. When I get to that point, I'm boring it out, working on the internals, T/C or S/C'n it, tossin on NOS and killing that 11.5 time we all keep hearing about! (ya, I want to make a true 4DSC out of my max and I got the cash flow to do it.)

Anyway, I'm out of ideas on your problem. I'd post it on the all motor section. Maybe one of those guys have run into the same thing.

EDIT: I looked at your profile: you're an automotive engineer? What company? I'm a ME from Purdue. Now I do engineered sales. Sorry about the off-topic rant.

IceY2K1

iTrader: (3)

Haha...since you've already got 3.5L, you just need liners not sleeves probably, so even cheaper.

Check out the 350Z forums for more info then I can give.

GBAUER

iTrader: (2)

Thanks, I'll be doing that in about 12 months.

Rob01ski

Hey Ice how about go to your nissan dealer on friday tell them about the problem leave the car their over the weekend and then let them hear it on monday when you start it up, oh yeah dont leave them the keys cause they might run it to say it was just something you dont have to worry about i run mobil1 5w-30 and nothing like that has ever happened to, could be do to the fact that it has all the oil drained down but i dought the start would be as roof as that, maybe you had a miss fire, have you checked you battery, or the power in your car maybe you have a short somewhere and its draining you power thus causing ruff starts.

GBAUER

iTrader: (2)

He already said it wasn't a misfire. We've covered the oil issue, and he uses a higher grade oil than you. I don't mean to flame a noob, but please read the post first.

IceY2K1

iTrader: (3)

If it does what happened today AGAIN, I will shut it down immediately and have it towed to them. Then *IF* it repeats the same procedure/noise, ie for 2-3 starts/30secs. or so, they should have an idea of what's wrong.

GBAUER

iTrader: (2)

Expect them to lie to you at least three times before you get the truth.

sascuderi

Ice, the day before this happened did you happen to start the car, move it a few feet, then shut it down and let it sit over night?

If I move my car a few feet (eg, move it our of the garage, wash it, move it back into the garage) and let it them sit over night, I have the same thing happen. Very much so with my 95 max and even with my 2000. (The first time it happened to me it sounded/felt like something was seriously wrong with the engine and I shut it down quickly in a panic)

I have looked into it, and best I can figure is that quick start up/shut down lets fuel sit in the cylander making for a rough few minutes the next day at start up.

IceY2K1

iTrader: (3)

YES, now that you mention it, I cleaned out the garage on Saturday. I moved it into the driveway on Saturday around 2pm, let it sit till 7pm or so, then pulled it back in where it sat until Monday morning when this occured.

IceY2K1

iTrader: (3)

What in the hell could that have caused to happen?

DAVEB

iTrader: (133)

Man, dunno if it helps, but my experience with VQ30 engine issues has more to with what they DON'T do. I have seen at least 100 P0420 & 30 catalyst replacements & NEVER seen evidence of ingestion on a VQ30. We did a cali-spec '00 with 193K last month & the catalyst honeycomb "looked" great. Failures of engine internals are ALWAYS due to massive oil abuse, which your car has not been subect to. This is really weird...

GBAUER

iTrader: (2)

Dave: you ever see blow-by on the 3.5's? Im losing oil badly (1-2 quarts every 3k, ya, I know it's "in-spec" but still it's excessive). Changed the valve cover gasket already.

BlackBIRDVQ

iTrader: (15)

When you fire up a cold engine, its given alot of fuel in the 1st few seconds of it runing- kinda like a older carbed vehicle with a choke. When you shut off the car there will be some fuel in the combustion chambers. Maybe what you are hearing is PRE-ignition, this is what happens when fuel is injected at the wrong period of time into the combustion chamber. I just did a engine on a 04 TL cause the guy had hydrolocked the engine with fuel. He bent the rod one day and kept on driving till it snapped and punched a H right in the block (h-beam rods), I found it pretty amazing since H- Honda hehe :P Anyways take it to the dealer and have them fire the car up with you there, so they don't give you no BS bout it.

My Pre-cat was totally messed up and my main cat was the 1st thing to go bad. On 01s and Cali spec 00s they use 2ndary butterflies in the lower intake manifold. After the clutch is engaged the Rpms blimp up for a split second between 2-3200RPMs, this creates effect similar to EGR and keeps the NOx emissions low. ECU controlls this function and there is no fuel injected into the cylinders when the RPMs blimp up, its all due to exhaust reversion and ignition of the totally unburned gases that get sucked back into the combustion chamber. This only happens on 5spds, on automatics they do things differently.

I got 105K miles on my 3.0L, without a problem. I got some chain slapp goin on slowly and my chain rattles on start up. I will be putting on a BLINB BLING timing chain cover that is all chromed out, at the same time I'm gonna repleace the chain guides, tensioners and the water pump. I wanna be all good for minimum of 300K miles on this motor.

DAVEB

iTrader: (133)

Yeah, we have an '02 with 71K that was using enough to foul the plugs on the rear bank & have a ton of blow-by, but the motor is pretty sludgy inside- oil abuse once again! I haven't seen a well-cared for VQ35 use a lot of oil for no reason, (except maybe yours!) but I did have a customer call on Friday claiming to have an '03 (yes, an '03) with 300K on it. Didn't see the car.

gratuitous

This is wack! I've had the same thing happen to me a couple of times, and it's always under these same conditions -- when I move the car a couple of feet, and it's not fully warmed up. I've been searching for a while trying to find some pointers on this board, and this is the first thread I've come across where someone has experienced the same problem. I can leave the car somewhere outside, it'll get below 0 outside, and I still won't have the problem. It's only when I move the car a couple of feet and then let is sit for a while. I've used Mobil 1 forever in the car, and thought that it was crazy to be a sticking valve lifter. This puts my mind at ease a little now. Now I just need to make sure that I don't do short moves anymore when the car is cold.

ecsdesignz

iTrader: (18)

haha old thread but yah i'm starting to get that noise too O_O 69995 on the OD O_O

AuAltima3.5

Same problem! I don't know what the deal is. Anything less than a minute or two, and then starting the next day, it will stumble for about 10-30 secs, and occasionally knock.

Dimashka

i had exactly the same thing happened to my car. I had a thread about it but no one could help me. It has happened once and never again. It as well happened after 4 days of not driving. so i think it could condensation in the engine or something like that. but until it comes back i am not worried. good luck.