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VQ35DE Engine Differences?


starbai
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Hey everyone. I have an 02 Pathfinder. The engine is shot.

 

I have a few JDM importers in town here and they have a VQ35DE from supposedly an 03/04 Pathfinder. Some shops are saying that the 03/04 isdifferentn than the 01/02... and some shops are looking at me like I'm a crazy person for asking why the VQ35DEs from the Pathfinder would be different across the 4 years they were offered.

 

That said, does anyone know defininitively if an 03/04 VQ35DE is different from an 01/02?

If it is different, are the differences material enough where the motor wouldn't work without some basic/small modification?

 

Lastly, and this question may be more difficult, any material differences from the JDM motor vs the USDM motor that may make this impossible? I know that I may have to swap my IM... but anything else I should be concerned about?

My goal is the easiest plug and play option here, I dont want to go into changing ECU's and other major items if I can avoid it.

 

Thanks in advance everyone!

 

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There's another similar post the other day (http://www.nissanpathfinders.net/forum/topic/43916-some-quick-help-needed/). Most notable difference is 03-04 are drive-by-wire, everything prior drive-by-cable. So just bring over the throttle body and check for any coolant plumbing differences. Beyond that, they were pretty much identical. If anything else appears different, should be able to bring over from your engine.

 

Bummer about the engine, though. What did it in?

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I honestly dont know yet.

 

I had the motor apart for a few months. I did timing chanin/water pump/guides/tensioner... I checked all valve clearances and replaced the lifter buckets as needed. New Oil pump while I was in there. I mean I really refurbed the thing.

 

A few months ago on a longer drive, oil light starts flashing at me... car started loosing power... major knocking/clicking ensued and the motor died.

 

I got it towed home and I haven't driven or had the time to figure out exactly what was wrong with it since. I tried starting it a few times with freshly charged battery and the motor doesn't even want to turn. I put a socket on the crank and tried to turn it and it was locked up. ITs still got all its oil no leaks.. So whatever it is, is internal. I'm just done trying to salvage it and figure at this point it'd be more cost effective to put a new motor in it and call it a day.

 

Before I ordered/picked up a new motor, I would at least do at least a little more investigation like checking for metal in the oil etc.

My guess is, and it's only a guess... is that some RTV broke off from somewhere, clogged an oil passage, and starved the motor till it died. My only clue as to what has happened thus far is that that oil light was flashing intermittently when I started the car... and went away for about a week.. then one day it came on, stayed on, and the motor died.

On another note, I considered swapping my IM/Throttle body off of my motor and putting it onto a new motor if I deiced to do with the 03 since there were no differences other than the TB... drive by wire... But before all those troubles mentioned above, I had a P1130 that wouldn't not freakin go away no matter what I replaced. So I was hoping that if I went with 'new motor' it would include its own TB/IM and all the @!*% that goes with it so that that code would no longer be an issue.

 


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For future reference here... I just got this feedback on FB... of course I cannot confirm it myself...

"If you want to use your ecu and harness you need to swap a lot off the original motor including cam sprockets, timing chain cover, upper oil pan, fly wheel, o2 sensors, upper intake plenum, throttle body, air box...you really have to convert the 03/04 engine to an 01/02 engine. Otherwise if you just want to drop it in as is you will need the entire front clip including harness, ecu, and instrument cluster, but I’m still not positive the new ecu would talk to the other units like transmission ecu. It was a huge pain but can be done"

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I agree there are some subtle differences, but is there certainty that they are what differentiate the newer from older engines, instead of just being part improvements that coincide with the model change? For instance, the cam sprockets have different p/ns, but the cams, camshaft sensors, and timing chains are unchanged...so would any cam sprocket variances be significant? Why would O2 sensors matter? You're reusing yours, plus the exhaust manifolds. Upper oil pan? That should only matter if the 03-04 transmissions changed mounting style.

 

But, let's put it this way: if the shop has concern about differences, just go with it. Bottom line is they are different, but perhaps not enough to matter if you were to DIY. If you force them to pursue work based the interwebs, it's going to blow up in your face. There are surely plenty of 01-02 donors that will eliminate any guesswork, so I'd go that route.

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Thanks. @hawairish...

To complicate things further, I now believe that the 01 and 02 Motors are different from each other.

Basically, you had 4 years of the VQ35DE in an R50.

04: Drive By Wire
03: Drive By Wire
02: Throttle Cable + Black Plastic Valve Covers
01: Throttle Cable + Aluminum Valve Covers.

This is how you can visually identify them.

The cam/crank sensors/coil packs (and potentially other things) are different from 01 to 02... So if you're in my position and you're trying to replace a motor from the 01/02... you gotta be sure you get the right thing or else you'll have swapped from the original motor the cam sprockets, timing chain cover, and god knows what else. I'm told that the 03/04 coil packs would definitely not work in an 01, and possibly an 02 as well.

I want plug and play... so for me, I need to find a motor with a throttle cable and black plastic valve covers it seems. IF anyone else has any other suggestions on how to visually inspect what I need I'd really appreciate it.

Local places def dont have an 01/02 motor in stock which means I can now only go off of what I can see in pics online. That being said I'll take any visual cues you can offer!

 

 

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Yes, and then there were the valve covers...if I'm not mistaken, the coil packs in the 03-04 models are the same as the 02 models with the plastic valve covers. It's the 01 that had the aluminums where the #1 coil was different from coils #2-6 because of a boss on the cover. I want to say later 01 models had plastic valve covers, too. RockAuto shows a split at 7/01...might have classified as 02 models.

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Now what scares me is if i find an 02 motor like mine, that has the black valve covers and the throttle cable.... that there are still even more variaations within that subset of 2002s that end up requring me to take off the timing chain cover which is what I'm seriously trying to avoid.

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Yes, and then there were the valve covers...if I'm not mistaken, the coil packs in the 03-04 models are the same as the 02 models with the plastic valve covers. It's the 01 that had the aluminums where the #1 coil was different from coils #2-6 because of a boss on the cover. I want to say later 01 models had plastic valve covers, too. RockAuto shows a split at 7/01...might have classified as 02 models.

 

Right I have an 02. and I know for sure I got the black valve covers and even with that, I know for sure that my #1 coil pack was different than 2-6.

 

 

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Wait...I was pretty sure the plastic covers (02-04) all used the same coil packs for all positions.

 

Also, I should add that my buddy has an 02 and there's an 03 engine in his truck. Casualty of the power valve screw. His swap was done by a shop, and I know with certainty it's drive-by-cable. I'll check with him if he remembers anything extra about the swap, but I really don't think there was anything special.

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I am inclined to agree with Hawaiirish. I am in the same boat as you (that's my thread linked above), in needing to swap my engine, and had asked whether there were differences between the VQ35s. I looked at the diagrams and indeed there are differences, but it is hard to tell whether the differences will result in an issue.

 

It may be the best option to find the same year engine as you are replacing, yes, and I may have dodged a bullet by finding a 2002 5spd 4x4 and grabbed the engine, tranny, and transfer case. However, I find it hard to believe that Nissan would have revised things so heavily between model years with the same engine that it would be as insanely difficult as the FB thread would have you believe. I'm not saying Vargas doesn't know what he is talking about, but some of the things listed are a bit trivial in my opinion, and shouldn't make a lot of difference.

 

As much as I know about Nissan's, it has become apparent to me that many items across the same model vehicle are more compatible than diagrams would lead you to believe.

 

I can also confirm that the no1 coilpack is different on my current engine as well, because it was a HUUUUUUUUUGE biatch to get the bolt that holds the coilpack down off and even though I hand tightened it half way I still cross threaded that SOB and had to easy out it in a state of panic, lol.

 

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I've been reading through these two threads...

http://forums.nicoclub.com/2003-pathfinder-with-2001-motor-no-start-no-spark-t613787-30.html
http://forums.nicoclub.com/01-pathfinder-3-5-swap-to-03-jdm-3-5-no-start-help-t614604.html

 

It seems that the biggest problem with the 03 vs the 02 other than the throttle body is the flexplate.

 

the 03 has a different number of cam/crankshaft position sensors. Without the right upper oil pan and timing cover, the ports dont exist in the right places for these sensors. And the cam sprockets are also different.

So in order to make sure I dont have to crack that motor open, I need to get one that has the correct cam sprockets and ports for cam/crank sensors.

At least I understand what I need.

 

To be as simple as possible, I have narrowed it down to an 02 motor. Visually from pics, I need to identify a throttle cable and black valve covers.

I've identified two possible motors that have these characteristics. What I need to do now is figure out how explain to ebay sellers to check for the cam postiion sensors and confirm that they exist where they need to. Once I do that I have to hope that the cam sprockets are the same. I'd HOPE that the black valve covers are enough to indicate that the cam senors are present where they need to be... I just dont know how to do this yet.

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OMG this is killing me!!! The day after Thanksgiving we went out to get a Christmas tree and I heard a tapping I'd never heard before. No performance problems, other noise or smoke. I pulled it over & had it towed to a shop. They were sure it was lifters and, after wresting with differences between early '01 and late '01/'02s we finally decided to do the heads. I told them I was worried about the Power Valves (I just learned of them from TowndawgR50 when I called him from the side of the road with the noise). They more or less considered this an afterthought and pushed for me to get a used engine. However, when we opened it up heres what we saw:

Power_Valve.jpg

 

That's 5 screws gone & the #4 butterfly valve in the #6 position. The rest of my engine appeared pristine but they couldn't find the screws anywhere & essentially refused to put it back together with any sort of guarantee. Again they pushed for a used engine but could only produce one with 118K on it. This pissed me off as I knew my engine was otherwise in excellent shape (I've had it it's whole life). After much back and forth over parts cost (Thank you Courtesy Nissan for providing me leverage) they suddenly found an import with 50K on it. It arrived yesterday and goes in today. Now I read all of this & I'm worried if it's even the right engine! Oh boy!

 

Here are the shots of my "new" engine. They sure as H#!! better have the right engine.

Import_Engine-_Front.jpg
Import_Engine-_Rear.jpg
Import_Engine-_Side1.jpg
Import_Engine-_Side2.jpg
Honestly, this whole Power Valve thing has really shaken my faith in Japanese reliability. I have to eat sooo much crow. I'm going to end up spending more than it would cost to buy my Pathfinder just to end up where I started. It's really disheartening!
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Kent, I really hate to mention this, but I'm a bit curious about that engine. For one, it's got the aluminum valve covers...looks like a 2001 engine. Two, those motor mounts...I don't recognize that. Ours are taller, the two studs are oriented 90° from shown, and that plate would prevent it from mounting to the subframe. However...I would be fairly confident that the upper motor mount bracket from your engine would carry over to the block and your motor mounts re-used. The upper oil pan looks the same, at least.

 

And man, your upper pan is pristine compared to the donor!

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OMG this is killing me!!! The day after Thanksgiving we went out to get a Christmas tree and I heard a tapping I'd never heard before. No performance problems, other noise or smoke. I pulled it over & had it towed to a shop. They were sure it was lifters and, after wresting with differences between early '01 and late '01/'02s we finally decided to do the heads. I told them I was worried about the Power Valves (I just learned of them from TowndawgR50 when I called him from the side of the road with the noise). They more or less considered this an afterthought and pushed for me to get a used engine. However, when we opened it up heres what we saw:

Power_Valve.jpg

 

That's 5 screws gone & the #4 butterfly valve in the #6 position. The rest of my engine appeared pristine but they couldn't find the screws anywhere & essentially refused to put it back together with any sort of guarantee. Again they pushed for a used engine but could only produce one with 118K on it. This pissed me off as I knew my engine was otherwise in excellent shape (I've had it it's whole life). After much back and forth over parts cost (Thank you Courtesy Nissan for providing me leverage) they suddenly found an import with 50K on it. It arrived yesterday and goes in today. Now I read all of this & I'm worried if it's even the right engine! Oh boy!

 

Here are the shots of my "new" engine. They sure as H#!! better have the right engine.

Import_Engine-_Front.jpg
Import_Engine-_Rear.jpg
Import_Engine-_Side1.jpg
Import_Engine-_Side2.jpg
Honestly, this whole Power Valve thing has really shaken my faith in Japanese reliability. I have to eat sooo much crow. I'm going to end up spending more than it would cost to buy my Pathfinder just to end up where I started. It's really disheartening!

 

 

 

 

 

 

Well... couple things to say here. One given the way my engine started knocking like crazy out of nowhere and also just died I'm starting to strongly consider that this was my motor's failure too. I don't know but I will find out.

 

As for whether or not the motor you have is correct, I would definitely say that it is at a 2001 motor, an early 2001 motor. I say this because 1. there's is a throttle cable so it eliminates 03/04... and I see aluminum valve covers so it's definitely not an 02 motor.

 

I hate to say this but I really don't think that that motor is going to work for you. They'll end up swapping many things to make this work. You'll need the new style flexplate. And for that flexpate you'll need the ability to connect the sensor next to it that will work. To do that I think you have to change the upper oil pan beacuse I thint hats where it mounts. The ECU will be looking for a different type of signal than the front cam sensors currently have because they use different sensors. Those different sensors require different cam sprockets. To mount those 'different sensors, you'll need your old timing chain cover.

 

Is this a USDM or JDM motor?

 

The good news for you is that since its at a shop they have the time/patience/and expertise to swap whatever they may need from your previous engine. If you have the ability to ask them, it would be extremely helpful for me if you can find out that, if it's a JDM motor, does all of the cam/crank sensors and mounting points exist where they should? It very likely does not.

 

For me personally, I REALLY, REALLY don't want to have to take off that front cover again or deal with the chains again. It was an utter nightmare and I'm still not confident that it wasn't something I did that caused my motor's eventual failure. The only saving grace that I did it correctly (and it was a subsequent failure of something else) is that I did run the truck for about a good 6 months and 5k miles with no problems after my work.

 

That said maybe it won't be so bad with it on an engine stand rather than me leaning over the fenders and grille on a step stool to get the valve cover on correctly.

Edited by starbai
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Kent, I really hate to mention this, but I'm a bit curious about that engine. For one, it's got the aluminum valve covers...looks like a 2001 engine. Two, those motor mounts...I don't recognize that. Ours are taller, the two studs are oriented 90° from shown, and that plate would prevent it from mounting to the subframe. However...I would be fairly confident that the upper motor mount bracket from your engine would carry over to the block and your motor mounts re-used. The upper oil pan looks the same, at least.

 

And man, your upper pan is pristine compared to the donor!

 

Have them check and recheck the cam and crankshaft sensors, I believe there are 2 per camshaft and two on the crankshaft. (Please correct me if I'm wrong, but we may all have a different perspective on this since it seems that that varied by year).. My numbers above are based on an 02 motor... or at least the 02 motor in My pathfinder.

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Just read this on my FB post... its the other way around but basically the same position you're in...

"I just did a swap from a pathfinder to a qx4 . 01 qx4
From a 03 pathfinder
We had to swap out pretty much everything from the plenum gasket up including all of the wiring harness. Because the qx4 has a boost sensor and the pathfinder does not .

Its was a bit of a bitch but it worked . All of the powertrain is the same .
I had to get at the knock sensor to replace anyway and thats under the manifold . Runs perfict now.
Take a look at the wiring
Harness plug and see if the same amount of power connections are there.
If you have 1 to many you will probably need to swap out what we did."

 

 

thing is, since he had an 01, maybe the ECU wasn't looking for all the stuff that it does in 04?

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Thanks everybody. I'm leaving work now and will stop by the shop and review what I've learned from you. It is a JDM engine. The mechanic seems competent and he's at least interested in the work (as opposed to finding it a pain). The mechanic intends to switch out all the electrical gear from my old engine, he's quoting about 4 hours of work. He seems comfortable with the job and he was the only one the shop manager thought could take it on. The shop management has been pretty clear but it's been a lot of back and forth. They definitely won't be thrilled to have me coming in last minute with these concerns from the forums but it sounds like it's potentially worthwhile. I wish they had listend to me more in the beginning. It's definitely not a consumers market here and unfortunately, I'm just lucky to have a place that will do it. Quite honestly, I'm pretty sure the management regrets taking it on. They're pretty used to fat wallets and no questions.

 

Even though they couldn't find the screws, they essentially looked everywhere. They had questions about them being in the short block and they were afraid that, even if they weren't, they might reassemble the engine and find the noise was still present. I wonder if the noise wasn't that powervalve #4 coming loose. It was a tapping form the back of the block on the driver's side that was relatively light but distinct & rev dependent. Part of me wonders if just fixing the powervalves would have made everything go away and save me the cost of essentially the whole truck.

 

I'm aghast at the cost but since the rest of the truck is in excellent shape with no rust and I know it's history from day it's cheaper and more reliable to keep it than to get a new one or something else. Also, and I mean this sincerely, I really treasure the NPORA community online and my friendly and generous locals like Kyle (ferrariowner123) and TowndawgR50. In fact, TowndawgR50 has been involved almost daily for the past couple weeks helping keep my sanity as the shop tried to test it. When it first happened, I called him from the side of the road as I was near his house. He was in California for Thanksgiving but helped walk me through things and brought up the power valve screw issue. I REALLY think we need to find a way to put that out there front & center. I've been on the forums fairly heavily since May and somehow hadn't run across it.

 

Sorry if this has been a threadjack, though it seemed relevant, and thanks for everybody's help.

 

Another quick question, would you do the timing chain on this 50K JDM motor. It adds ~$1,200 to the job ($440 labor(=4 hours here) + >$760 parts (and that was after I talked them down using Courtesy Nissan's pricing). I doubt I'll put another 50K on this truck in the next 10 years but I would like it to last about a decade and I've been puttin on about 5K/yr for the last couple years once it was no longer my daily driver again.

Edited by RainGoat
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Another quick question, would you do the timing chain on this 50K JDM motor. It adds ~$1,200 to the job ($440 labor(=4 hours here) + >$760 parts (and that was after I talked them down using Courtesy Nissan's pricing). I doubt I'll put another 50K on this truck in the next 10 years but I would like it to last about a decade and I've been puttin on about 5K/yr for the last couple years once it was no longer my daily driver again.

 

Honestly, What I've learned from my mess is that sometimes it's better to not mess with things if they're doing okay. I get if it had high mileage...but since it does not. I think its worse to open it up if unnecessary.

 

On the other hand, it seems like they're going to be cracking that timing cover off anyway. I don't see how they're going to use that motor without ultimately taking that timing chain off to swap out the sprockets anyway... so what it boils down to is what the real cost of chain replacement? It shouldn't be anything more than parts beacuse you're already going to be paying to swap all that stuff out of that motor of yours. In this case, might as well put a shiney new chain on it. What I will say though is dont mess around, replace the chains, guides, tensioners and water pump with OEM. Dont do what I did and go with ebay for some of this stuff... you'll regret the money and time u've put into all this just to skimp on the parts if you dont.

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Honestly, What I've learned from my mess is that sometimes it's better to not mess with things if they're doing okay. I get if it had high mileage...but since it does not. I think its worse to open it up if unnecessary.

 

On the other hand, it seems like they're going to be cracking that timing cover off anyway. I don't see how they're going to use that motor without ultimately taking that timing chain off to swap out the sprockets anyway... so what it boils down to is what the real cost of chain replacement? It shouldn't be anything more than parts beacuse you're already going to be paying to swap all that stuff out of that motor of yours. In this case, might as well put a shiney new chain on it. What I will say though is dont mess around, replace the chains, guides, tensioners and water pump with OEM. Dont do what I did and go with ebay for some of this stuff... you'll regret the money and time u've put into all this just to skimp on the parts if you dont.

 

Well, TowndawgR50 had offered to help me with this but it was just too big of project to as someone else to help with and neither of us have a protected space where the truck could sit for the weeks it would have taken us (and it rains nearly constantly here in the winter). The shop insists on OEM in order to warranty it, the trick was using Courtesy Nissan to drive their parts prices down somewhat. Labor here is $110/* so that hurts. Adding the chain to this swap is $1,200, going back to do it later is $1,800. Definitely cost effective to do it now but I would not have expected to need it in my engine at all if I hadn't had a failure and I'lll probably not top this new engine out past 100K. I've got to make my mind up this morning but I'm leaning towards no - as you said, maybe they'll have to get in there anyway in which case I might reconsider.

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Well, the saga continues....I dropped by the shop with a summary of everybodys findings to find that the mechanic had stripped the JDM down & just come in to ask the shop manager for a different engine. They were to busy to elaborate & said wed reconvene this afternoon but the manager was already on the phone inquiring after an 02 Pathfinder engine because the mechanic said he had some concerns with the current one. Maybe it had to do with the issues youve brought up. Ill keep you posted!

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