Awful noise at startup.. 99 Q45

[ESFITNESS]

car's a 99 Q45t with 109k miles, paid $5200 out the door.

2nd day I had the car, I went to start it and got a loud "screech/whine"... the same noise you get when you go to start your car when it's already running, except it wasn't running. I turned the key off, and tried it again, and again and got the same noise... then it started.

now, a couple weeks later, it's done it about 4-5x total... a couple of those times the noise ended with a loud "thump/thud".

the car drives fine, although for a v8 it seems weak. at least when accelerating from a steady 20 or 30 to 40 or 50.... I don't feel any misfires or hesitation and the idle is just fine (if a tad noisy on the front end)..... also, I can smell gas when startup near the driver side when I open the door.

also, it sometime takes a few seconds of turning on the key for the engine to turn over.

it did throw a code a week after I bought it, and when I took it back to the dealer to run the codes, he said it was the gas cap, but when I went look over his shoulder at what other codes there were, I could've sworn I saw a 'knock sensor' code or a cam or crank position sensor (I wrote them down as soon as I was back in the car), but that was a couple weeks ago and no codes have been thrown since. if it was a knock sensor or cam/crank pos sensor, two weeks would be plenty of time for the code to show again, I would think.


soooo... my main question is WHAT'S CAUSING THE SCREECHING SOUND AT STARTUP!??!? lol.... I spent 3yrs in automotive tech school like 10yrs ago, but I can't figure this out.

thanks.

[Q451990]

to NICO!

My guess would be that you have one or more bad tensioners on the accessory belts. They will tend to lock overnight and cause some belt squeal on start-up when they get really bad. They'll whine a little, like a bad alternator or transmission to. The colder it is outside, the more you'll notice this.

I'd pull the belts and check for any roughness or noise when spinning the tensioner pulley... they should be very smooth and quiet.

As far as your codes, knock sensors won't light the "check engine" light, but when they're bad they put the engine in a safe mode of sorts that can cause performance issues like you describe. It's probably time to get it hooked up to a scanner somewhere... be it a free one at a parts store, or a real technician somewhere, just to know what you're dealing with.

Heath

[BadQ45t]

and you need to stay away from the dealership for sure. I think the advise you just got was spot on, I can tell you while this is not the power of a 2013 V8 for sure it is a V8 and has plenty of oomph when it is in good condition.

The knock sensors, coil packs, spark plugs are all in the same place when you have the car opened up from all the plastic covers. If you goal is to keep this car for 4-5 more years acquire all of those parts and do them all at once. yes it will be a bunch of money for parts (and labor if you cannot DIY) but that will probably be the main parts you need to get performance back.

[ESFITNESS]

to NICO!

My guess would be that you have one or more bad tensioners on the accessory belts. They will tend to lock overnight and cause some belt squeal on start-up when they get really bad. They'll whine a little, like a bad alternator or transmission to. The colder it is outside, the more you'll notice this.

I'd pull the belts and check for any roughness or noise when spinning the tensioner pulley... they should be very smooth and quiet.

As far as your codes, knock sensors won't light the "check engine" light, but when they're bad they put the engine in a safe mode of sorts that can cause performance issues like you describe. It's probably time to get it hooked up to a scanner somewhere... be it a free one at a parts store, or a real technician somewhere, just to know what you're dealing with.

Heath

it's not really a 'squeal'.. I didn't know how to describe it... it's the same sound/noise you get when the engine is already running and you turn the key to start it. (and no, the car isn't already running when it makes the noise)... doesn't really sounds like a belt.

I've found knock sensors for about $60 online.. searching now for a 'how to' on replacing them myself, so long as it doesn't involve removing the intake manifold. lol.. I've seen 3.5hr labor estimates so far, that's about $315 + tax where I live. The dealer says he'll do labor at $45/hr, but I dunno if I trust the dude after his employee/cousin/brother cleared the codes before I could write them down... i'm sure I saw a PO330 code at the very least.

I wasn't expecting it to be a beast of a v8, but I guess i'm used to the 5.9l magnum in my old truck... even my gf's 08 g35 seems to put me in my seat harder.... even at WOT.

[Skibane]

it's not really a 'squeal'.. I didn't know how to describe it... it's the same sound/noise you get when the engine is already running and you turn the key to start it.

Almost sounds like your starter has a problem - Either something's loose inside it, or it isn't meshing properly with the teeth on the engine flywheel when it's spinning.

You might try looking under the car to see if the starter looks like it's been replaced recently - Might be something as simple as a loose or missing starter bolt.

and you need to stay away from the dealership for sure.

+1.

Relying on a dealership for repairs to a well-used car is a sure way to go broke quick.

If you MUST use a mechanic, find a good independent garage.

[OwnerCS]

Where are you located? We may be able to recommend a "known good" shop.

[Q451990]

When you say "dealership" are we talking about an Infiniti dealership, or another one where you purchased the car?

Heath

[ESFITNESS]

it's not really a 'squeal'.. I didn't know how to describe it... it's the same sound/noise you get when the engine is already running and you turn the key to start it.

Almost sounds like your starter has a problem - Either something's loose inside it, or it isn't meshing properly with the teeth on the engine flywheel when it's spinning.

You might try looking under the car to see if the starter looks like it's been replaced recently - Might be something as simple as a loose or missing starter bolt.

and you need to stay away from the dealership for sure.

+1.

Relying on a dealership for repairs to a well-used car is a sure way to go broke quick.

If you MUST use a mechanic, find a good independent garage.

something 'not meshing/lining up' is what I thought at first. sounds/feel like the starter teeth are locked up and not spinning when I turn the key.

the dealership isn't an infiniti dealership.. it's a used car dealership. I do have a place down the road that I trust, and they give me a AAA discount, it's a lil better than $90/hr labor.

CEL still hasn't come back on.

I gotta calculate my MPG... rough est is i'm getting about 14 avg, but i'm in Palm Desert (palm springs) and it's not like San Diego where 85% of driving is on the freeway. my drive is 8miles to work, and only about 3 miles is on the freeway... everywhere else is stop and go with traffic lights and a max speed of 45.

[nuuBeeq45]

Ya it sounds like the starter gears wernt meshing up right before the starter motor started spinning. My 2000 AE has done that a couple of times.
Ya,stay away from the dealer for repairs. If you can,wonder back to the service garage an infiniti dealer has and talk to the techs themselves,they love to share info but it's frowned upon by the bean counters in the front office.
This car does have some issues with all the computer/sensor stuff. Would like to just go to carbatooter and magneto for fuel and ignition. The engine itself is pretty good as a unit itself,it's all the accessories/sensors that bog it down.

[OwnerCS]

If you are not far from SD, there was a Jerry Tucker All Import Service in San Diego at 858-573-1118. Not sure if he is still around.

[ESFITNESS]

i'm actually in Palm desert, but i'm FROM san diego (mira mesa), and head down to san diego pretty often. i'll check him out.

now, if the Knock Sensor's are showing codes, wouldn't that mean the engine is knocking for some reason? and wouldn't that be the bigger problem?

[Q451990]

A knock sensor code means that the sensors fail their self test... it's a common issue. When they fail their test, the ECU goes into a full safe mode in terms of fuel mixture and timing advance to protect the engine - essentially "assuming" that it "hears" knock.

Heath