*HELP* G overheated,now won't run properly !
 

So my Infiniti was running perfectly fine and then overheated one day. (Luckily I was already pulling into my driveway as I noticed the temperature gauge climbing)

After getting it towed and diagnosed I realize I needed a new radiator (obviously) and somehow in the mix the battery went out also..

get all this fixed, then go to back my G out of the shop and hear the loudest CLUNK ever, then as I enter drive, the vehicle will barely climb over 1500rpm

Could this be from the coolant leaking onto trans sensors or into the trans?

PLEASE HELP. Nearest dealership is over an hour away and I really would rather self diagnose first before I waste any more money at 140/hr for this old thing

Is it throwing a check engine light, typically when it's in limp mode it's also got codes attached telling you WHY it's in limp mode. Start by getting it on an OBD2 scanner.

How was the vehicle towed? On a flatbed?

Well, I had it towed by rollback and took it to a guy I've been dealing with since my first vehicle... He performed all the repairs, (never had driving issues prior to this) and CLAIMS he never even backed it out of his bay after making the radiator repair and battery change.

It didn't throw any codes when It first cranked;we tried resetting the computer by letting the battery sit disconnected.. Didn't work... The guy told me he would figure it out, then dodged me for a while and never told me anything but now says his computer "says it's transmission sensors, or it needs a new transmission" . He did not provide the exact codes, nor a repair estimate to simply fix what wasn't wrong in the first place so I just left it there.

But, this in fact IS limp mode like I thought? He said he didn't think that was it. I also heard the Nissan's and some vqs have issues with radiators busting and leaking coolant into/onto the trans and nearby sensors

You cannot tow a G35 with the rear wheels on the ground, it's a RWD vehicle and doesn't have reverse oiling. It may have smoked the transmission, I would have it PROPERLY towed (on a flatbed) to a local reputable transmission shop and then if the transmission is shot send the other guy the bill.

Here's a link to the owners manual for the 2006, everything pertaining to towing is the same between all model years 2003 and newer.

https://cdn.dealereprocess.net/cdn/s...i/2006-g35.pdf

Here is a snipped of the towing section.

https://cimg5.ibsrv.net/gimg/g35driv...56f4951832.jpg

Most vehicles on the road will experience a radiator failure at some point, it's just the nature of the beast. I don't believe your overheating issues and transmission issues are related unless you fully hemorrhaged the thing but you would probably know if you were bleeding out all your coolant and transmission fluid. The tranny starts to slip VERY quickly when it's pressure drops and you have no choice but to pull over because it simply won't propel forward anymore. There are no transmission sensors in the forward section of the engine bay on these vehicles.

Also you can easily determine if it's in limp mode because the engine will not rev above 2000 rpm in park.

Sorry, I had to look at the video when they towed it (this has been almost 7 months ago) and it was a flatbed. So, the theory about them burning my trans out from towing it is out the window.

My question now is, if its in limp mode, would it still have good power in reverse? Because the vehicle has FULL power in reverse, but when you shift back to drive, DEAD.

(Thanks for your time/input so far also sir, I DO appreciate it.)

Yes, limp mode doesn't cut torque output it just sets a very low rev limit. Reverse will always feel strong because it's such a high gear ratio.

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The next step will be a coolant pressure test to verify there are no leaks, a compression test to verify the overheating didn't damage the motor.

If those both pass and it still isn't driving properly I would take it to Nissan for a diagnostic, their computer is much more detailed than what most shops have and the car computers can be put in diagnostic mode where they self-check everything.

(Sorry for late response, I'm just now getting back used to Forums lol)

But, yeah its looking like its dealer time .. I just got the vehicle back... Now im back at square 1 because even with the new battery in.. The vehicle suddenly wont start again, and is seeming to not be holding any power. Put my battery charger on it, and it lights up green like the battery is fully charged and ready to crank..

I try to crank it, and it almost just seems to surge as if the battery is bad or something

Could this be crankshaft/camshaft issues, or sound like ECU? I'm just lost at this point and considering parting lol

Spin it by hand and see if it's siezed