My Axiom engine install 6VE1 (late)

[Espritmike]

I bought my 2001 VX in June with 88k and change in miles. I was concerned with the fact it had the engine replaced at 65k miles and warrantied at 81k. I have receipts for the 123Engines build plus labor, which in my opinion was way too low to have been done right. In my case the crank broke in front of #1 rod journal so the build may not be the problem. I have owned a AAA approved shop going on 20 years now and am very OCD about my engine installs. When pulling this thing apart I noticed missing bolts from motor mounts, one missing exhaust donut, water hoses pinched under intake and loose and damaged torque converter bolts. After having 2 motors local motors sent and refusing due to quality, I tracked down a June 2002 unit with the screw in PCV valve and 82k miles on the odo (CARFAX documented). We replaced the normal things- PCV valve, intake + plennum gaskets, timing belt-including idlers, tensioner piston assy, serp. belt, thermostat, water pump, spark plugs and I even stepped up and bought Denso reman alternator and starter assemblies. Started it today and it sounds great. In my opinion, outside the fact that these have piston and PCV design flaws, nobody builds a better motor than the factory. Thats why when putting motors in cars here at my shop its - Used, OEM dealer crate motors or JASPER.------

[Espritmike]

Now for the differences from our VX motor to the "Axiom screw in PCV valve" motor. I know the DI engine (2004) is different, you can see even the timing covers are different. But here is a list of what is differences are to the '02-'03 motors.
1) Upper intake plennum- Axiom motors have 3 threaded mounts for some kind of module, other than that looks to be the same.
2) Lower manifold- same except the bolt pattern for the throttle body is smaller on Axiom motor- Throttle plate appears to be the same diameter in fact.
3) Wiring harness different- obviously
4) Axiom motor does not utilize the cam position sensor at rear of drivers head- had to remove valve cover and punch out plug to install the VX sensor. Camshaft is the same and does have trigger pointer for sensor though.
5) Ignition coils are totally different and have different plugs but our coils bolt right on to valve covers.
6) PCV different but Axiom hose plugs into same place on intake soooo.
7) Axiom does not use knock sensor- but the threaded hole is in block so VX sensor screws right in.
Everything else I swapped over- motor mounts etc. so not sure what else is different, but the fact is, if the late model motor is improved, I should be okay.Mike

[vp277]

Tell us about your driving impressions with the new engine. Is it the same displacement, stoke, bore, etc?

[nocturnalVX]

I know where to go if I ever need to replace my VX's motor...

[TheGanzman]

Thanks for taking the time and effort to weigh in on this! Please keep us apprised on it vis a vis short & long term results. Good to see that you're "local" to me if mine ever takes a dump...

[Espritmike]

My VX ran fine when I got it in June, although never driving one its hard to compare it to anything. It did pass smog (I ran the test myself) but the motor was always a little noisey. Through the fenderwell I could always hear a mechanical noise. Not sure if it was just the exhaust leak on the passenger head pipe, valvetrain or the broken crank. It is possible the noise could have triggered the knock sensor to back off the timing causing loss of power, but the new motor definately runs smoother and has seems to have more power. 50 miles on the clock so far. Vp277, the motor is virtually identical. By what I can see the only differences are the pistons (more drain back holes), and the drivers side valve cover (PCV valve mount).

[Leon R]

Nice write up, Mike! I completely agree with your on factory engines! In fact, I would go a step further and say that I distrust all rebuild motors, unless I know and trust that particular builder!

I wonder if the crank failed due to being cut down? A practice adapted by many BIG engine rebuilders...

Would you recommend upgrading to 02/03 PCV system?

[Espritmike]

Leon R, I suspect cutting down the crank caused the failure also. I had it happen when my brother-in-law ran his 3.0L Ford Ranger out of oil and seized the crank (only had 29k on the truck!). We rebuilt it and 200 miles later the crank broke in half. Never made that mistake again. Time will tell, but to me the late '02-'03 Axiom motor seems to be the ticket. Now If you tear down an early motor and change the pistons (more drain back holes as documented in a few posts here), that too could solve the problem but I'm not sure how much the PCV system makes a difference.
Here is the thing, I could have installed a reman motor, probably done right, but, it would have been probably $3200 just for the longblock. As it is I got lucky and got this motor for $1200 plus shipping ($165). Most of the ones I see are $1700-$2100 used. On top of that I put another $900 or so in misc. parts (gaskets, starter, alternator, torque converter etc.) PLUS about $600 which is what I paid my tech to install it (we were slow the last few weeks so I could justify it). That is $2900. I paid $9300 for the VX in June and didn't really want to drop another $4900 into it, BUT I do still have my standards and wanted it done right. If someone just walked throught my door and I did the exact job, it would have left at over $5000! Of course I toyed with putting the 5.3 E-rod or equivalent into it but that would be about $15-20K and I have waaaay to many things going on in my live to justify that kind of project.

[Marlin]

I would love to drop an Isuzu diesel in the truck,I would be just fine with the loss in power for the durability/versatility/dependability of the diesel. But mine runs like a champ, had the same ticking noise from the passenger fender for 5 years, partially a crack in exhaust manifold, partially valve tap. No other issues, at about 150K miles now.

[Espritmike]

I would love to drop an Isuzu diesel in the truck,I would be just fine with the loss in power for the durability/versatility/dependability of the diesel. But mine runs like a champ, had the same ticking noise from the passenger fender for 5 years, partially a crack in exhaust manifold, partially valve tap. No other issues, at about 150K miles now.

The valves are adjustable on these. Although a pain

[Marlin]

Yep, I watched the tech video for how to shim them, I know myself well enough that I do not have the patience for that kind of detail work. I also realized that it doesn't matter, and just about every 3.5L trooper I have ever heard has the same tap, so no worries here.:smack:

[Y33TREKker]

I've often wondered if a competent motorcycle tech could do the valve adjustment if he/she also had access to the factory Isuzu VX valve adjustment tech videos to watch before starting the job.

I say that thinking back of the shim-in-bucket valvetrain system that was used in all of the large-bore inline-four Kawasaki street bikes I've owned over the years. 900 Eliminator, 1000cc Ninja ZX-10, and 1100cc Ninja ZX-11D.

[Espritmike]

They use them in v-6 Toyotas and some BMW motors. I had an E34 M5 that was set up like that. I had to pull the cam boxes so I measured the valves,pulled the boxes (including the camshafts) and re adjusted. Way easier than trying to compress the valves with the special tool.

[Leon R]

Of course I toyed with putting the 5.3 E-rod or equivalent into it but that would be about $15-20K and I have waaaay to many things going on in my live to justify that kind of project.

I keep going back and forth between adding a mid-mounted turbo to 3.5 or going with LS4 engine. LS4 is very cheap (as little as $900 for engine with engine harness!), but you need to address starter issue (there isn’t a provision to mount one on the engine). Ether way, I also have too many projects going on right now, so I am glad I have time. As long as my 170k miles engine doesn’t come down with rod knock…

[nfpgasmask]

Yeah, this is good info. Thanks for posting.

Bart