'99 Q45t with a shake problem

[johngalt]

I am new to Infiniti's, and am "still" reeling from all the information overload. I have found a lot of info that contradicts what I have been told, and am wondering just exactly what is going on here with my car. Seems to be mechanical, but no one seems to know for sure.

Scenario: I have driven the car a bit, and pull up to a stop light. After wasting some amount of time (inversely proportional to the operating temp it seems) the car abruptly "shudders' as if I have just been involved in a low-speed MVA - I at first thought it was only at operational temp, but this morning I drove to a doctor's appt., came out 1.5 hours later, and cranked the car - drove for a tenth mile and stopped at a stop sign - and it manifested (immediately) - and it was not at normal OT by any means.

I was told by the previous owner that the idle RPMs are supposed to be around 900 RPMs, but then found this page, which shows the idle should be around 600 - which is a bit "lower" than my car actually idles at to begin with (usually 700-750). However, I also see that the compression for each cylinder should be 185, whereas the pre-purchase inspection including compression test I had performed on the car prior to buying it at Infiniti of Gwinnett in Atlanta showed 7/8 at 210 or better, and 1/8 (#6) at 205. Granted, I am nowhere near a mechanic, being more of a Computer junkie and tennis player, but I want to learn. And I don't mind getting dirty.

So, any one have any ideas on what ht shudder / shaker / quake is? Or at least what to tell a dealer to look for when I take it in next? I ma the third owner *and* it has high miles (138K+)? The car is in great condition, and rides smooth, and I am having an oil change performed this afternoon - using Mobile 1 oil and filter, as that is what the previous owner stated he used (M110 filter and 10W-30 oil).

I have a rash of questions but now realize that I need to read a lot on this car before foraging out into the wild blue yonder (which I unfortunately did not do before posting at freshalloy).

EDIT: Added the followingOh, BTW, I *did* search for shake and shake q45 as noted by elwesso, but found nada. a search for shudder found so many links to posts that someone used the word shudder (referring to themselves / their bodies, usually after empathizing with someone) that I gave up.

Modified by johngalt at 10:22 PM 12/14/2005

[Q451990]

I would absolutely skip the dealer service appointment and have the guys at T3 automotive take a look at it. Byron at the S. Cobb location is excellent. Many of us on the board drive literally days to get there... you're lucky to have them in your back yard!

Welcome to NICO!

Heath

[elwesso]

If you find a better place for the Q45, I can tell you id be there!!!!!

I would try cleaning the TB and MAF and see if that resolves it... Should only take an hour or so..

[SardarQ]

Just curious... check the voltage reading on your battery when car is on with a digital voltmeter... and post.

[maxnix]

Check and clean the EGR and IAC valves and connectors.

[SardarQ]

Some common problems (in order of importance):

1. MAF ( clean it with the proper spray)2. Change your air filter if dirty3. Clean the TB4. When in the TB, clean your IAC

Some uncommon reasons which may cause this:

1. Bad coil(s)2. Bad alternator (or going bad - volatge reading close to 13V during charge).

[FarFetched]

In my opinion, you need to look into replaceing KS (knock sensors) and (posible) harness. I had the same shudder/studder problem. After replacing KS (both) the problem is gone!Also, do a throttel body clean up and MAF sensor connector inspecton.

Cheers!

[johngalt]

I appreciate all of the extremely quick responses - however, I have to figure out what half o this stuff means. I was a driving enthusiast, but haven't learned all the nitty gritty details of this car yet.

Specifically, I see several different suggestions, and *lots* of acronyms, and I will find most of them in here I know, but I think searching for 2 letter acronyms may not work. Anyhoo, I need a lot more basic info to begin with - what, for example, is T3?

I think the best thing for me to do at this point is to find the basic links, such as basic maintenance, recommended repair shops, etc, and see what I can to from there.

I will try Googling for T3 and South Cobb and see what is up. Hopefully I can get out there today and see if it is going to be a major thing or not.

EDIT: Added the followingI cheated, since I cannot get the digital pics off the phone yet and the camera is buried somewhere else, I found pics of a car *extremely* similar to the one I purchased.

http://philanet.com/~zcar/99q4579.html

*it* has heated seats - I don't. I also emailed the lot to inform them they have a V8 in there not a V6.

Oh, that reminds me - I looked up the VIN specification and based upon the VIN of my car (and, interestingly, of the above car) I found something very weird.

using this page and my VIN, I see something *really* weird. Specifically, the fourth 'digit' of my VIN is B, and according to that page, it is supposed to be a

Code: Select all

B KA24DE; SR20DE

engine - and I am like WTF?

I found the links at q45.org for T3 - gonna call them up and see what they are looking like today.

Thanks again for all the help folks.
Modified by johngalt at 10:38 AM 12/16/2005

[johngalt]

Then again, I just realized that there is not a 4.1L engine reported there, so that might have been added in for that particular letter designation later on....

EDIT: Added the followingI just called T3 - spoke with Ty - and he said Brain has not worked there for a number of years now. I wish I had called two days ago - he might could have fit me in today - but he needs a couple of days - so it looks like I am waiting until after Christmas.

And it also looks like I may be looking to get a second one - I love this car a lot - and I think my Mom will too, since she is currently driving a '92 Maxima.
Modified by johngalt at 10:51 AM 12/16/2005

[96Qowner]

Heheh, it's Byron, not Brian, and Byron's the chief Infiniti tech, anyway - not really the guy to talk to on the phone. T3 knows everything there is to know about all the Q45's. Trust 'em. They work on literally hundreds a year.

And I'm sure some more 2nd gen Q45 owners here will chime in, too. My first thought was that it's MAF related. Dirty and failing MAF's can cause a shudder and/or stall when you come to a stop. It can cause idle hunting, too.

[johngalt]

OK, I now realize that I did actually say Brian, as opposed to Byron - sheesh, I must need sleep. I think I will g o along with MAF first and see - I also need tension rods and have a right rear leak in the suspension, according to the pre-purchase inspection I had performed.

Now to find out what a MAF is....

[Q45tech]

Mass Air Flow devices have been used on many engines since the late 70's [even GM started using in 1984 on some engines] and joined their cousins the MAP [manifold air pressure].

Just like the first electronic fuel injectors go back to 1966 in UK.

http://www.annagarrison.com/MAFS.html

[goody90q45]

Interesting article. The entire fuel injection circuit is very well managed for performance, fuel economy and emissions. You hear a lot of complaints about how emissions systems have cleaned the air but reduced performance, which I think happened with a lot of the 80's-90's cars. In the Q, the emission system allows you all the performance you want (well for most of us) and manages fuel economy and emissions quite well. Most cars with this kind of acceleration and speed only get 8-10 mpg where the Q gives you 15-20 mpg.

[Q451990]

OK, I now realize that I did actually say Brian, as opposed to Byron - sheesh, I must need sleep.

If I remember correctly - Brian was one of the service writer / shop manager/ lawn upkeep / front end guys. With all of those duties they burn out quickly!

Heath

[johngalt]

@Q45tech: Thanks heaps for that article. Bookmarked for further study.

@goody94q45: I have to agree, that the raw power I feel in my car (and the couple of times I have opened her up flat out from stop) have almost unnerved me in the sheer response time and acceleration, and yet the mileage that I ma getting is pretty decent. After I get some minor things fixed I will start really watching the mileage - currently it seems to be giving me better than 18 mpg, so I really cannot complain.

EDIT: Added the following@Q451990:

I'll bet - sounds like a Net Admin triple dutying as a Help Desk Tech *and* as a Test Bed Deployment tech....which I have done by myself....

[elwesso]

John, it sounds to me like you just need to start doing your basic tuneup things....

[johngalt]

yeah, I probably should - but I need to learn so much more about the car itself - I'd hate to make a stupid mistake / let someone else make a stupid mistake on my car...

[99q45t_vl]

Did you get your problem resolved?

[johngalt]

no, not yet. I missed the meet, I haven't had the opportunity to get to Atlanta and leave the car up there (I think I spoke with Ty on the phone) and I only have today off from work as a result of a broken finger....

I *did* replace the A/F with a new one (and yes, I went with the K&N) and it seems to have gone away for the interim - but then again, temperatures have also been near freezing at night, and I haven;t had as many stops to deal with.

With today being so pretty (even if nippy) I am going to do some testing on my car and see how things are.

[maxnix]

I *did* replace the A/F with a new one (and yes, I went with the K&N).

Not a beneficial choice. More reading of the previous posts and you will learn why.

[johngalt]

If there is a serious detriment to using them in the Q I haven;t found it yet in my reading, but then again, I still haven';t had a lot of time to read about the car - and I keep seeing designations for it that throw me every time - like G50 and Y33, etc.

Anyhoo, I will continue to read to see if there is a real problem with the idea of using the K&N for this car - 'cause if it is only the price, and anyone who wants to argue with me is welcome to, at $15-18 a pop for the OEM and at $37.xx shipped for the K&N, I figure that I am coming out ahead inside of 3 years. (I have already added 3K miles to my car in 1 month, so 36 / yr means A/F pretty quickly).

[maxnix]

OEM is less than $8 from Joe. Compare the filter area to K&N.

Saving money to allow grit into your engine is no savings.

[Q45tech]

In general we have seen a much higher MAF failure rate with oiled type filters than with oem paper types.Of the 17 MAF we have replaced in the last 5 years more than half were on cars with K&N cone filters.....see so few K&N drop in filters hard to correlate.

Anyway why mess with oil medium and take the chance so many other items wear out fast enough that Nissan doesn't need any help.

Worrying about an $8 oem [even a $20 ONE] air filter every 1-2 years is infinitesimal.The newer less robust MAF require that the ecu be recalibrated every time one is swapped so be especially careful on post 2001 versions.

[johngalt]

OK, point taken. I should have done the research, but as I used the drop in as opposed to the cone, and it was factory oiled, I figured I was better off once I saw the price comparison.

Live and learn.

At any rate, the temperature here has been rather nippy (and at times downright cold) but I have noticed that for the last week or so the 'searching / seeking' that this thread refers to has not been evident - until, that is, the temp jumped up to a frigging blistering 69 F - then, I was at a stop light, the car had been running for about 10 minutes, and it occurred once.

Hence, I realize that now I need to get some time off and get the car over to T3 ASAP and let them take a really good hard look at some of the things that I need fixed (as already diagnosed in the pre-purchase inspection I had performed) as well as see what other stuff I need to start looking at.

[FarFetched]

Have you tried BG44 yet?Have you tried different gasoline (brand)? Some are crap some are good. Y33 for some reasons very picky when comes to gasoline. Mine is!If BG44 makes it (hick-up) go away then its your fuel system (most likely). If it doesn, you are looking into KS, harness (possible) full tune up (minimum) .That's just for starters!Cheers!

[johngalt]

Well, been using primarily BP, but this problem was prevalent from the day I bought the car. With the new A/f it is now a lot less pronounced, indicating that it probably has to do with air intake somewhere.

I have no idea what BG44 is, but that is what they make search for, right?

***runs to find bg44

[maxnix]

BG44K

http://www.bgprod.com Sold by http://www.everythinginfiniti.com

Lose the K&N for OEM. There is no OEM oiled air filter.

Keep going. You are on the path.

[johngalt]

Yeah, I know the OEM is not oiled. That was a selling point for me with the K&N, as my '97 Eclipse performed better with it's drop in K&N.

At any rate, I have it now, and need to get an OEM, so I am stuck with it for now. Besides, I need to do the torsion things next anyway, and that will probably be a good time to do the OEM A/F.

The good news is that since the replacement the shake is almost non-existent - having only seen it twice since I have installed the K&N, so the dirty as hell OEM that was in there was contributing at least partially to the problem. When I tackle the MAF (rather, let the T3 folks tackle it) then I have a feeling it ill fade into nothing more than a bittersweet memory.

[nermq45]

I have read through this whole thread, lots of ideas and input. Can anyone tell me where I could find out about how to clean the MAF and the TB to try that to see if it fixes my problem? I am a relative novice at self repairs but not afraid to try anything assuming it is not something tremendously difficult to do.

Thanks!