Hey fellas,
Wow, it's awesome to see other guys getting closer/completing their swaps! It's worth it in the end! Anyway, here's my periodic update...
The truck runs great! As I've said before, this was the best mod I've ever done!! But nothing is ever absolutely perfect as I'm sure you guys know! Here are some issue that have been ongoing after logging ~10K miles post-swap...
Exhaust: I went with compression-bent, 2.5" piping from the manifolds back, into two Magnaflow cats, then into a dual-in/single-out Flowmaster SUV 50 muffler, with a 3" tailpipe. It worked great until I eventually got used to the new sound of the engine, then I heard it...the drone. I would be cruising around 2K RPM/65 MPH and the engine/exhaust would be SOOOO drone-y inside the cab. I mean to the point of not being able to hear someone speak!! I dealt with it for awhile since I was rarely was driving in that regime, except for a few miles on the freeway each day. Anyway, I finally decided to do something about it and redid all the floor insulation. I laid down some Damplifier Pro from Second Skin Audio, followed by 8# carpet padding from Home Depot. In the front, I added a thermal blanket in between the Damplifier and padding. "That should do it!" I thought. Not quite. Although muffled, the drone was still loud & annoying. So I decided to move to the exhaust itself. After a little bit of research on lextreme, most guys were installing 2.25" piping into their SC/LS400's. That apparently was the magic number for the exhaust unless they were planning on super/turbo charging. Anything bigger than that, and you got the drone. So it seemed my 2.5/3" exhaust set up was a little too big for a naturally aspirated 1UZ. Anyway, I took the 4Runner in and had the Flowmaster replaced with a 24" Magnaflow and had the 3" tailpipe replaced with 2.5". It helped, but still the drone continues. I considered replacing all the piping with 2.25, but that's just ALOT more money. I think the next step is to install a resonator in-line in the tailpipe. What do you guys think? Anyone have similar problems with their exhaust set-up?
Oil Pan: After investigating a leaking oil pan, it looked as though the custom pan I had built was a little too tight between the front differential and front cross member. When I took the measurements for it, I failed to take into account the torquing of the engine under load and settling of the rubber in the motor mounts. I'm sure the pan had been contacting the frame every time I gunned the engine. So I replaced the custom set-up with a stock LS400 pan. Here's where I found a new problem! When I was originally fitting the 1UZ and taking measurements for the motor mounts, I had a pretty banged-up oil pan installed on the motor. I didn't realize just how dented it was until I went to install a near new oil pan...it wouldn't fit! The engine sits too low in the vehicle and a "normal" oil pan contacts the front cross member. I'm either gonna have to make new motor mounts or install a spacer place somewhere to raise the motor in the engine bay, away from the cross member.
Oil Leaks : I noticed this shortly after driving the car after the swap. The seal on the black oil pan was leaking along with the front crankshaft seal. After replacing the custom oil pan, the leak around the top went away. But every morning I find a nice fresh oil spot on the driveway. I've looked and looked and found both the front and rear crankshaft seals are leaking pretty bad. I replaced the front seal when I rebuilt the engine but not the rear. Plus I remember on the front seal, that I had a bitch of a time getting it to seat correctly. Obviously it wasn't!
The last big issue I've been having is a near constant CEL with a code of P0420: "Catalyst System Efficiency Below Threshold (Bank 1)". I keep resetting it but it comes back within 50-75 miles. I've already replaced the front O2 sensors (they came with the motor) but I still get the same code. My exhaust guy thinks it might be because the exhaust is flowing
TOO well. I don't seem to have any exhaust leaks so my next guess is to replace the cat on the left side. You guys have any suggestions?
Anyway, that's about it for the update! I think my next big project will be to buy another 1UZ and have it rebuilt professionally. I replaced all the necessary seals, gaskets, etc before installation of this one, but it still leaks! Plus, I want to go all out and have this thing ported & polished, etc. Smitherz did it right from the beginning!
