The Q45: what a stupid car.

[paranoidjack]

Good site. Imagine the size of the crankshaft grinder lathe?

Jack

5.6million lb/ft?

Weak.

[ZMARKUS]

maxnix
Re: The Q45: what a stupid car. (DoinkMobb)
Unread post 05 Apr 2008 17:14

You need to read Q45tech's early posts. The Q45 and President were designed for upper level executives who had the car serviced every 90 days by a factory trained technicians. DIY bohunks in the US maintaining them was not even on their
radar


I know this thread is from 100 years ago but this comment is so full of logic that I had to comment. It illuminates how irrational it is for a DIY Infiniti/Nissan owner, to expect cooperation from their car's engineering, when attempting to tackle repair themselves. I won't go as far and say poor people trying to maintain rich people cars as one of the post stated. Yet, it does question does the desire to own a particular vehicle, eclipse the ability to maintain it.

[98_Q45]

maxnix
Re: The Q45: what a stupid car. (DoinkMobb)
Unread post 05 Apr 2008 17:14

You need to read Q45tech's early posts. The Q45 and President were designed for upper level executives who had the car serviced every 90 days by a factory trained technicians. DIY bohunks in the US maintaining them was not even on their
radar


I know this thread is from 100 years ago but this comment is so full of logic that I had to comment. It illuminates how irrational it is for a DIY Infiniti/Nissan owner, to expect cooperation from their car's engineering, when attempting to tackle repair themselves. I won't go as far and say poor people trying to maintain rich people cars as one of the post stated. Yet, it does question does the desire to own a particular vehicle, eclipse the ability to maintain it.

Good point you make. And now as we can see in the “future”, many new cars are not only hard to work on but: most people don’t even seem knowledgeable enough to do it in the first place (knew a guy years ago calling the dealership at 7 am to get an oil change, saying he didn’t want his engine to blow up if he doesn’t get it on time SMH. Like bruh…have you ever been 1,000 miles from home, with 8,000 miles on the oil? Nothing happens unless you run out lol). Add in the fact some parking lots, apartments and even storage units prohibit work/maintenance on your vehicle ( I think I see a whole statute in one state forbidding people to do it). For what is worth: the car manufacturers have no need to make it “easy” to work on stuff anymore.

It sounds good, but that often equates to packed auto shops, expensive labor, and just overall incapability to maintain one’s own vehicle.

That said, not sure which gen Q this person was writing about originally: but at first I thought the Q was a complicated beast, however over time I’ve realized it’s actually built very well. I have a Cadillac, same year …and even though I do some of my own maintenance: trips the shop have proven far more expensive each time, than the Q.

Just this week, I had $1,000 repair bill. Part of that was from brake lines sprung a leak and rusted out, something I’ve never experienced on a vehicle before. Couple years ago the tensioner for the water pump seized, ruining a pulley in the process. And that pulley had to be pressed into the camshaft. $500.

The only 3 things with the Q I find unreasonable, are the starter placement, the A/C compressor location and the differential cover (it should not have been required to drop the diff to remove the case). Other than that, a front facing engine makes it very easy to change the alternator and all the belts.

[VStar650CL]

For what is worth: the car manufacturers have no need to make it “easy” to work on stuff anymore.

It isn't a matter of "no need" so much as designs which are intended to be built by robots and not disassembled by people. I can point you to dozens of instances where moving a fastener a quarter inch would cut hours off a repair job or obviate the need for special tools. There actually is CAD software which can analyze and optimize the ergonomics of repair, but nobody uses it. I'm not sure why, because it isn't like companies aren't paying for those extra hours on warranty repairs. Maybe AI will change that in future designs, we can always hope.

[fontana dan]

This thread was a very entertaining read lol thanks for bumping.
I've wrenched on my Q45 from front to rear and I've never had too much frustration. I've done plenum gaskets, spark plugs, AC compressor, struts all around, diff bushings. The list goes on. My impression is that it's average as far as ease of repair goes, but finding quality replacement parts is near impossible at this point.

[cbird805]

That's why it's called the dreaded Valley of Death plenum job. It's something you put off until it's absolutely necessary. I've jumpered a knock sensor mounted on flat piece of aluminum and bolted it to the back by the idle air valve. I'm certain one of my injectors is starting to go bad, and trying to find ways of arthroscopically removing and replacing them. If I can loosen the fuel rail just enough to remove the bad injector without taking on the plenum somehow- it would be easy as a piece of cake! The worst part of removing the plenum is trying to find replacement hoses, gaskets, and all the misc. hardware that got damaged. I've learned not to throw anything away, no matter how insignificant the item may look. Some of those rubber grommets cost over $50, if you can find them. Good luck and we're here to help should you run into any unforeseen issues.

[fontana dan]

True that on not throwing anything away. I regret throwing away a couple of major original components I removed from my car. The aftermarket replacement stuff is not in the same league of quality whatsoever. I keep everything now.
Possibly my biggest frustration with this car though, besides parts, is the lack of knowledge. I feel like I'm on my own to figure out any and all problems. There are not many "experts" who regularly chime in on this forum. That's a difference I've noticed in the ownership of this vs more common american cars.

[cbird805]

I usually do a search of the forum, if i ever get stuck in a rut. I recommend downloading the FSM for your model and year. Do you currently have any questions you want answered? i’ll try my best to help you.

[fontana dan]

I have the FSM downloaded and refer to it religiously. It is a huge asset.
How are you certain one of your injectors are going bad. Did you ohm it?
The issue that has had me stumped for the longest is the P0171 and P0172 codes my car likes to set once in a blue moon while idling. Long term fuel trims bank 1 and 2 are +20-30% only at idle. Symptoms are that of a vacuum leak, but I have not been able to chase it out for the life of me.
Is the fuel system on these cars known to cause lean misfires at idle? It seems to kind of act up on hot restarts. What are the symptoms of a failing fuel pressure regulator?
Thanks for your time.

[VStar650CL]

The rich trim at idle pretty much rules out a leaky FPR and leaky injectors or seals, all of those would cause extra fuel and shift the trim negative. I'd also doubt a fuel pump issue, because a weak one will generally starve the engine at high RPM and cause balky cold starts. You might have a "hidden" vacuum leak like a stuck PCV Valve or a pinhole in a vacuum solenoid or brake booster diaphragm. Did you mean P0171/P0174, or are you actually getting both rich and lean codes on the same bank? If it's the latter, I'd suspect your bank1 front O2 has a problem.

[fontana dan]

My mistake VStar, the codes were indeed both banks lean, P0171 and P0174. I also believe there is a hidden vacuum leak but I can't find it for the life of me. New PCV valves. I've done smoke tests, I've tried isolating the "hidden" culprits by pinching off their lines. No luck. I must be missing something due to the maze-like arrangement of the vacuum system.
I also have a slight misfire creeping in especially when the car is hot and idling or under load at low rpm but its very intermittent. No codes. What is the best way to do a cylinder drop test on this older model car?

[cbird805]

Have you tried using propane to find the vacuum leak? I find it works a bit better than smoke test for hunting down vacuum leaks sometimes. With the engine running, take a propane canister, barely cracked open, point the nozzle (DO NOT LIGHT) by vacuum lines and components, listen for engine rpm to rise. Good for checking hard to reach places. It may sound dangerous, but really isn't. Just don't smoke while you're doing it.

[fontana dan]

Have you tried using propane to find the vacuum leak? I find it works a bit better than smoke test for hunting down vacuum leaks sometimes. With the engine running, take a propane canister, barely cracked open, point the nozzle (DO NOT LIGHT) by vacuum lines and components, listen for engine rpm to rise. Good for checking hard to reach places. It may sound dangerous, but really isn't. Just don't smoke while you're doing it.

Yes I've used propane. I even put a hose over the end of the propane nozzle so i could direct it under the intake plenum, etc. No luck.
I've also done the propane test while logging o2 data looking for a spike to rich, Because a lot of time while the engine is idling the o2s dont switch, they just stay nearly flatlined at .1v. Or they will switch for a minute then stick lean and go open loop randomly, doing bizarre things which I do not understand.