I did a 3.5 swap on my 97 maxima last fall. I haven't been able to work on it much during the winter. I just captured a video of it. It basically runs like liquid dogsh!t as can be seen in the video.

http://media.putfile.com/35-96

I put a new timing chain, tensioner, and guide in it. After putting in a new timing chain, the fuel pump does not turn on unless I power the fuel pump manually. I checked the fuel pump relay and its fine. The fuel pressure is set to 50psi. All cylinders are firing. All cylinders have 190psi of compression.

The engine only has 800 miles on it.

What really worries me is the metallic clanking sound that can be heard in the video. Piston valve interference????

I checked the timing and it's at around 15deg BTDC.

The only codes it throws are relate to EVAP and the IACV.

I've put so much damn time and effort into to this that I just want to push the car over a cliff. Does anyone have any suggestions?

 

You'll need IE to view the video.

 

i no how you feel.once i get this video to play i'll see what i can do to help

 

Sounds sorta like 3.0l did when i spun the rod bearing. Is the sound better or worse when the engine temp is warm?


BTW what did you do to fix the compression issues you were having? I did one on mine and it read almost exactly how yours did.

 

I just took the upper IM off and peered into the lower im and all the intake valves looked good. They weren't bent or anything.

 

No vacuum leaks?
No blockage of fuel?

that metal claking like sounds cant be good at all. Which area is the sound originating from?

worked fine with firefox.

 

Man i wish i knew , good luck

 

Just saw the video.. Have you taken off the valve covers and checked to see if the cams/buckets/etc are all okay?

 

I was doing some more troubleshooting and found that there is no compression in cylinder #3 and that the intake valves are not closing and the piston is coming up and hitting them. That's what the sound is.

 

well that blows bad.they video nvr worked for me.does the motor still got a warranty?

 

i figured it had something to do with the valves. Looks like you were right on about what you suspected. Wasn't cylinder 3 compression at 190 before?

 

def was a valve problem, hopefully you can use the warranty on the motor still

 

whered u get the motor from ? ... junkyard ? ... did it come with certificates for the tests they ran on the engine b4 they sold it to you ?..compression, leakdown, etc... ?

 

+1 on the vavle problem. My dek was bad too, rod knock and spung bearing. The sound is totally different but hopefully u get another 3.5 in there soon. Good luck.

 

Here's the two intake valves on #3 with the buckets off. No obvious damage there.


Here you can see that the two intake valves are stuck open about 1/2"


Here's cylinder #3 whose piston looks to be in good shape. There's a small mark where it looks like it was hitting the valves.

 

There may have been a 6 month warranty on the engine, but I bought it back in september, so it's too late now. It didn't come with any certificates of tests being done and I didn't really think of it since it was basically a brand new engine. As can be seen in the pics, the engine is clean as a whistle. I really don't see any reason why I can't fix the valves and use this engine.

I'm still kinda stumped on the noise and the lack of power though. I would think it if the piston was hitting the valves, there would be more damage than there appears to be. Especially with the racket it was making. If the cam timing caused the problem, I would think that it would cause problems on other valves as well. Even if you have one cylinder with no compression, I would think that it wouldn't run as poorly as it was. I had a 2000 maxima with two bad coils and it ran better than this 3.5 did.

I'm not sure if I might have overlooked the cylinder or what when I was compression testing a few months ago. What would cause the valves to get stuck like that???

One thing I was thinking about doing was getting some PF heads to put on it so I could use the 00vi and have the ports match up. I bet the 00vi with PF heads would really make it scream.

 

having a cylinder like that would cause terrible running. the air from the cylinder would go in, but then go out on the exhaust, would kinda be like backfiring without the spark. the valve reliefs on the pistons may have saved you from serious damage, as they didnt get bent or anything. are there any springs for the valves? could be super weak springs or something.

 

I just removed the two valves. Looks like I did have a couple of bent valves.



Should I simply replace the two valves or should I get new guides as well?

 

Nicely bent, there.

I'd get new guides just to be on the safe side, I've seen guides somehow catch a valvestem and bind it, keeping it from going all the way up or down, and it's possible that in the short time you've been running with those two bent valves (or not so short time, whatever), they may've ****ed up the guides.

In any case, like I said, better to do it now than have to pull off the valvetrain and head to replace the guide at a later point.

 

yeah, replace them, the valves being bent like that may have messud up the guides

 

why would a new 3.5 with 800 miles have problems like this ?? .. not properly breaking in the engine in its first 800 miles ?? ... someone shine some light as to how this could have happened in the first place

 

perhaps the timing was off in the first place.

Good thing I got a 1 year warranty on the 2 3.5's I bought.

 

If your valve timing is off, then all three cylinders in that bank would be affected the same way.

It is a bit of a puzzler how two valves in the same cylinder get bent when the only mechanical elements they share in common are the camshaft and the piston.

If I had to guess, I would say that the engine was seriously over revved in its short life.

 

I would think that with the 3.5, you would throw a rod before you would have valve float. It is weird though that only 2 intake valves in the same cylinder would be affected. Usually when the cam timing is off, it'll affect more than that. In addition, I've revved the engine to redline so if the cam timing was off I would think that more damage would have been done.

I ordered the parts from dave B and they should arrive early next week.

 

"Throwing a rod" generally occurs due to a failure of one or both rod bolts. Rod bolts will generally always fail as a result of a fatigue crack initiating from the threads or a surface defect in the shank of the bolt. It can take many thousands of high stress cycles to intiate a crack and then many more thousand before it grows to a size whereby the remaining section can no longer support the load.

On the other hand, valve float can occur in an engine with 0 miles on it due to a single inadvertant downshift.

 

From what I understand, anything over 7200rpm with stock rod bolts on a vq35 pretty much guarantees a rod failure. The engine was mated with an auto tranny in the donor car before being installed in my car, so it'd be pretty hard to overrev it.

 

Don't get me wrong, I agree that you will have a stock rod bolt failure if you make repeated runs to 7200+ by means of an extended rev limiter. That is probably not a high enough rpm to ever see the onset of valve float.

However a single rev to 9K+ can float the valves and not cause any observable damage to the rod bolts other than possibly a little measureable strain.

Being that your engine came from an auto, that possibility is pretty remote.

I just hope that your engine did not sustain any other damage that is being masked due to the rough running with the bent valves.

 

Hahahahahaha, man I understand EXACTLY how you feel just from the delivery of "pissed sighs" in that video. You have figured out and solved at least one problem. Get and install valves and guides, then come back with the results.

 

wahoooooooooo. Fletch Lives!!! My only problem now is that the fuel pump doesn't turn on by itself. I have to run some jumper wires to get it to turn on and build up fuel pressure. I tested the relay manually and it worked. The fuel pump fuse is good.

Any recommendations?

 

Wiring between the relay and pump must've gotten frayed somehow. I guess now would be a good time to wire a kill switch directly to the fuel pump wiring.


J/k lol...glad to hear she's up and running finally.