Hi guys, I’m almost about to hit 150k on my 07 and I’m kind of in a jam. Cooling system started breaking down, got a new radiator, hoses, thermostat, changed fluids, belt. And I’m not close to being done with trying to get things up to par.

While I was doing this I started accumulating everything I would have to do With internals at this point. And correct me if I’m wrong. But I’m looking at replacing spark plugs, coils, fuel rail, injectors, POSSIBLY pistons and a new head?, and god knows what else I need cause I’ve never hit 150k in a vehicle.

whatever is remaining may cost well over 1000 to maybe install myself. And instead of checking things off one by one I was thinking to drop it all and just get an engine with 50k for like 1500 or something just put that sucker in there and be happy with that.

ive also thought of taking it to a machine shop for a rebuild but trusting someone else with oem specs and measurements seems like a long shot.

im completely lost.

hope that made sense to u. I’d like to know what everyone else would do and maybe pros and cons of each direction?

thanks all!

 

These motors can last well over 200k-250k. Your mileage may vary depending on if you were using **** oil, and how well you took care of it.
Do do a compression test and a leak-down test. If they are fine stop worrying about opening up your block. If the coils arnt bad why are you replacing them?
Change your spark plugs, Freshen up the timing side of things (New chain, new guides) While you are in there get metal oil galley gaskets, change the water pump and seal.

Sounds like you are just replacing everything just to have it new.

 

Let's try to get you out of the LOST neighborhood. First, has your Z already had the major service at 100K? Next, what do you mean by the "cooling system breaking down"? Was your HR overheating or what were the specific symptoms?

The first thing to understand is that the VQ35HR is a precision-built engine. That means you need to know what you're doing and from your past posts, it seems like you're still searching for an upgrade. I'd suggest you STOP before painting yourself into a corner and reconsider what you're capable of doing.

Unless you have well over $1K to invest and are an expert wrench, completely rebuilding the HR is not a realistic goal. Depending on your answers to the first few questions, there's no real need to do so. Replacing the fuel rail, injectors, pistons and heads shouldn't be necessary for most DIYers in tuning up their HR.

 

I see, I was looking at some manuals and service intervals and saw that at 150k things should be considered being looked at so I started expecting the worst and peeled into doing all that.

looked into timing chain kits for the HR but it’s hard as hell to find one or I’m just dumb.

so first thing I should do is a compression test?
spark plugs,
then the timing kit?
not sure how much it will help but I got an obd2 reader coming maybe that will give me a clearer picture.

 

I’m sure it had the 100k service.
Here’s what I meant by the cooling system... long story.

car stalled and overheated one day, somehow drove it home only able to get to like 2500 rpm.
replaced thermostat, bottom bolt was broken in the hole, had to drill a bigger hole, put an insert and installed the thermostat.
After burping it ran okay for a couple days then started heating up and leaking coolant on the other side. So I got a new radiator, hoses, and a prayer to God or Allah or whoever is mightiest.

And yes I agree that I shouldn’t touch any precision made equipment so that’s why I had to think of the option of getting a used motor and just hitting the reset button in a way.

and I’m not entirely sure if the radiator is the reason why it’s overheating in the first place! Makes me wanna just drag my nuts on broken glass and die from loss of blood

 

Sounds like you have air in your coolant to me. These cars can be a bit picky about burping the system.
Everything i said is if you want to refresh the engine, might not even be necessary. I thought you were coming at this to make it new again.

I would 100% do a compression test and a leak-down test if this is a new car to you. Knowing the motors health will give you peace of mind. Especially if its showing good numbers.

 

i 100% want to refresh the engine but like dk advised, I don’t want to open something that was made with precision.

anybody know where I can find a used HR to throw in there?
ive looked at junkyards and eBay but nothing caught my eye for something I’m gonna spend that much money on

 

Before you look at throwing a used HR in there, it's NOT like hitting a reset button. There's no way to know what kind of treatment and maintenance a junkyard motor has received. If your HR has had the 100K service and regular oil changes throughout, it's a better option to keep that engine going. Get an experienced Nissan or ASE tech to do a compression and leakdown test FIRST and examine the results. To repair your overheating issue, get a Lisle funnel to fill and burp the new radiator properly.

 

Make sure the radiator fans are turning on. Mine went out on my DE a couple years ago and all I had to do was replace them. Had me thinking it was the thermostat at first too.

 

Ok thanks for the advice.

and by the way. Has anyone brought up anything about what kind of sounds and/or signs someone might experience for any serious or minor issues?
Reason why I ask is before I can bring it to get it tested I have to resurrect it when I receive my radiator, I want to try and detect as much anomalies as I can so I don’t get hit with something I wasn’t expecting.
for example, certain clicking sounds, knocking sounds from an area, noises when sitting idle..?

besides junkyards I could only find ipp long blocks or something and I’m not sure where to even start with one of those and if it’s even alright if I stay N/A with one of those and drive it as a daily? Shrug

in the end what I want is a clean strong NA HR motor. Turbo problems are not problems that me or my bank account want.
but even after all the frustration anxiety and pain I’m feeling positive about what I can achieve with this baby

 

yea I actually tried to bleed some air out in between and it was working until it just stopped cooling and started overheating, made a u turn and went straight home and saw it was steaming and leaking. Hopefully I’m correct about the radiator.
gonna go get a lisle funnel to bleed it correctly and if everything seems good I think I can take a small break from worrying about the car and make a game plan with the testing and whether I should maintain it as it is, re-do timing, rebuild, or look for another motor.

 

So while I patch up this cooling system I’m hoping to find other irregularities that might call for concern. Got an obd2 reader not exactly sure how accurate it will be as far as giving me my issues, especially with the o2 sensors cause I know I have test pipes and if I know anything about electrical, which I really don’t, test pipes will trigger that check engine light and sensors will not read properly sooooooo.

like I mentioned earlier does anyone have any notes or anything as to what problems one can point out using sight sound and smell when it comes to knowing if I have to get the timing chain looked at, if I have a blown head gasket, if pistons or going to **** or if I need to bore the head? Which is why this chain of thought led to saying “screw it I might as well find another engine”

 

Wow- I don't know what brought on this case of automotive hysteria, but unless you have some abnormal sounds coming from the front of the HR (where the timing belt is) there's no need for a lot of concern. As others have said, 150K is not a lot of miles for a well-cared for VQ engine, so don't go looking for problems. Now, if you've been abusing the engine by overrevving it, not changing the oil/filter, or bouncing the Z off curbs, well it's time to confess and freak out...

 

DK has the patience of Job. OP- get your temp problem solved, then get a shop to do leak down and compression check. Update this thread AFTER doing these things. Good Luck!

 

Lol!! I think I’m traumatized from dying on the road... and I take care of my ride, only drove about 4K in a couple years but I’m very thankful to have everybody’s guidance on this. I will update all after compression test! Thanks crew!