Engine Swap or Cylinder Head Job?

la_fx35

la_fx35

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Location
Chicago
Car
2017 QX70S
Name
Andy
My brother-in-laws 2003 FX35 (my old FX35) with 170K miles has misfire on cylinder 4 and I have diagnosed down to a leaky exhaust valve on the cylinder.

I'm trying to decide if I should just replace the cylinder heads with rebuild ones or swap in a low mileage engine, or a rebuild engine. Whats holding be back on doing a cylinder head job is the 170K miles on the engine and I'm un-familiar dealing with the timing chain. It use oil quite a bit due to worn seals/gaskets due to the high mileage it has; about a quart every 3000 miles. I have asked a couple shops to do the cylinder head job and they advise not to given the high mileage on the engine.

Swap in a low mileage engine seems to be the easiest route. I do understand the risk of inherit any problems of the replacement engine may have. And I also realize there is a separate set of problems with a rebuild engine may bring as well.

Feel free to charm in.
 
Andy...I say swap in a low mileage engine. This one already has 170K on it and is burning oil. You will save yourself headache in the long run.
I think if you get a rebuilt engine from a reputable shop that knows the VQ35...that should be fine too.
 
swap, I am sure you can find a good VQ for relatively cheap and if you can do the swap yourself that's even better.
 
:rotfl:... OK, a "How to: Swap your engine" DIY if it comes to that.
 
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If you go the engine swap route one thing I'd suggest is having another FX standing by to compare stuff to. When I helped swap an engine into my buddy's Z it was really nice being able to look at another Z to see where stuff went, like wiring harnesses and cables. I don't remember that being too hard, but I also wasn't there for all the work, and it wasn't my car so there was nothing to get stressed over.
 
Thanks for all your input. Swap... it is.

---------- Post added at 08:36 AM ---------- Previous post was at 08:34 AM ----------
StuLax18 said:
If you go the engine swap route one thing I'd suggest is having another FX standing by to compare stuff to. When I helped swap an engine into my buddy's Z it was really nice being able to look at another Z to see where stuff went, like wiring harnesses and cables. I don't remember that being too hard, but I also wasn't there for all the work, and it wasn't my car so there was nothing to get stressed over.
Click to expand...

Does your buddy get to listen to the engine or he buys it online?
 
If I remember correctly the guy had bought it to swap himself but never got around to it, so my friend bought it from him. Pretty risky, but I think it worked out. I'd think you can find one out of a wrecked one in the rear and maybe get to hear it run.
 
If you have alot of time on your hands it might be worthwhile to pull the head. I mean it could just be carbon stopping tge valve from seating completely flush. I mean it would be fairly cheap to just buy 1 valve,stem seals & have a machine shop clean it & put the stems on. But then again its up to you if you have the time and its alot more time than doing a swap. But if you want the chain learning experience To do the chain is pretty straightforward. Nissan has color coded chains so you just line up the colored teeth with the marks on the sprockets afterward & reset the tensioner.
 
Hmm, thanks for the insight Edwin on the timing chain. I will look into it. Pulling the head definitely much lesser time then the entire engine.
 
I'm sure it's a long shot, but does tchuck still have his spare engine laying around?
I'm not sure if he pulled the heads apart, but it seemed like he had fun with the pistons, rings, and bottom end.
 
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If you get the engine from a reputable place, they should offer a warranty of 30 or 90 days (or something like that). Lots of them verify that the engine was running before they pulled it.

I agree with the others to swap it, you'll get a lower mileage motor and the labor isn't going to be significantly more than just pulling the head. Just swapping the head involves a lot more precision. I swapped the VQ30 on my old turbo Maxima when a lean condition melted a piston and it was honestly ~10 hours at a friend's shop on a lift. Just make sure to bag and label all bolts and label all harnesses. The FX has a lot of room so I don't think it would be too bad.
 
Thanks again everyone for your input. Car-part.com and ebay; here is come. Anyone know of a reputable vendor?
 
I bought mine from LKQ, they're pretty big on eBay and have been around for a long time. I think I bought my motor from them in '05.
 
LKQ is where I got my glass. One thing, I ordered over the phone and the next day my CC had a fraudulent charge on it. I was told I had to purchase it and then they'd tell me when it was ready for pickup the next day, so that's why it was over the phone.
 
Yeah lkq actually offers warranty on their motors. The lower the mileage the better the warranty. You just gotta confirm warranty with them & have them put it on the receipt. Also ask them if labor costs are covered incase you get a bad motor. Thats if you choose that route. Besides its alot easier to just swap a motor in and call it a day than going into the internals. But then again its all your choice bro. B
 
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