An overdue introduction

[sewebster]

An overdue introduction and my saga to this point

 

Last fall an acquaintance of mine was selling his 91 SE as he was going on an extended vacation. I do a lot of outdoor activities up here in BC (mountaineering, hiking, backcountry skiing) and around here that means logging road access, so I've kinda wanted a 4wd for a while. I decided to go have a look. Truck was basically described as not looking pretty but being functional. At this point I knew nothing about Pathfinders or really trucks in general.

 

It had pretty bald 33" Mud Terrains on it when I got there, with a 1" lift (unknown springs in rear, torsion bars cranked a bit). Was a little banged up on the outside, but seemed generally ok. Frame looked fine. Took a test drive. Definitely a lot different than I was used to, because, a) it was manual, which I didn't really know how to drive, and my other car is a 2 door small car. Felt like a beast, but it drove around. I talked him down from $1500 to $1200 and decided to buy it and just see whether I liked it.

 

A few days later I was doing a better job checking the oil (I think I checked it when I bought it and he said it had been changed recently) and ended up deciding that I couldn't see any on the dipstick. My dipstick anyway is more confusing than I am used to… seems to pick up a lot from the tube so you need to be really careful to find the true level. Anyway, that seemed bad if the oil was low. Decided to change the oil.

 

When I drained the oil, basically the worst stuff I've ever seen came out. It basically looked like grey liquid metal. There were significant metal shavings in the drain pan. So this had me somewhat bummed. I'm the kind of guy that doesn't like driving a ticking time bomb, and I did know that it wasn't really running super smooth, so I figured the engine was about to die.

 

At this point I guess I had a few options, including: just drive the truck and see what happens, sell it again (might not be so honest), or, I could do what I did, which was rebuild the engine. I had previously replaced the crankshaft in my car (driven without oil by a roommate after the rear main seal blew), so I had some experience removing and installing engines and figured I could just do a relatively quick job in a few weeks. I knew I'd be putting some cash into it, but I figured by ordering stuff from rockauto that I could do it for reasonably little money, and then I'd have a good engine. I also figured I'd learn something.

 

So I arranged to work in a friend's garage, since I don't have one, and set about tearing things apart. Got the engine out and stripped it all the way down. I have some pics of this process online here:

 

The dude with the long hair is a friend, I'm the guy with no hair. Old guy is the friend with the garage.

 

Somewhat surprisingly, I didn't find anything supremely wrong. The piston ring grooves were quite worn and stuff was pretty gunked up though. I started doing a ton of inspection based on the FSM instructions to make sure everything was in spec. As I went along, I kept deciding to replace some more stuff "just in case." So I got new pistons, rings, bearings, valves, lifters, rockers, rocker shafts, probably some more stuff in there too. I ended up getting the cylinders bored 0.5 oversize (matching pistons) and the heads machined and the valve seats ground. I didn't replace the oil pump because it kinda seemed expensive and I did all the inspection and decided it was good (foreshadowing).

 

So I put all this engine stuff back together. All this took way longer than I expected, like a couple months. I am a student (doing PhD in physics at the University of British Columbia) so my schedule was flexible, but I was still trying to do school stuff). Anyway, eventually got it all back together to my satisfaction. Put the engine back in. Replaced clutch (and pressure plate and bearing) even though the old clutch was still basically good.

 

Started it back up and it was making a pretty terrible clattering sound from the top end. Eventually stuck my hand in the oil fill port and found some rockers were totally loose. Took the cover off and one of the rocker shafts wasn't tightened properly. Sigh. Felt pretty dumb about that, but didn't seem to do anything bad.

 

So I was driving it around the block and stuff (did break in procedures first etc.) and this is when I really started to notice how messed up the transmission was. Basically makes bad sounds a lot of the time, like when you let off the gas, semi-bad sounds in 3rd and 5th, pops out of 4th when you aren't on the gas etc. Oh well. It also seemed to handle badly and make noises. So I decided I needed to take a look at the suspension etc.

 

Basically all the shocks were the OEM ones and were toast, especially the rubber bushings at the end, so replaced those. Also found out that my tie rod ends were toast too, so did them as well. I guess I was anxious to start using this thing outdoors, so I bought new tires, 31" (this is smaller than the 33s that were on there before) Goodyear Wrangler Duratracs. Were recommended to my by a friend and I really liked that they had the snowflake symbol so I could feel good about driving them in the winter. Anyway, while I was driving home from the tire place, I noticed that a slightly remaining top end noise from the engine seemed to be getting worse, and the engine would hesitate sometimes.

 

So, i pulled off the passenger rocker cover again to see what was up. I was very dismayed to see that one of my cam lobes was chewed up and there was metal in there. Pulled the lifters and the lifters was totally chewed up on the bottom (this was a new lifter). Measured the diameter and it was oversized. Now that I knew I could notice that it didn't slide as smoothly in the guide plate. LAME. Pulled the plenum and the other rocker cover and there was the same problem on that side! So now both my cams were destroyed. Things were not going so well for me in this rebuild process.

 

I guess I was too far into it now, so I ordered some cams from RockAuto. One of those ended up being out of spec, so I found one locally at a cam shop (I highly recommend Shadbolt Cams to anyone in Vancouver BC or the lower mainland). Anyway, I also started ordering more lifters and after several attempts I finally got some that were in spec. I can't believe how many out of spec lifters I measured. Ridiculous that these people don't check their product better. I also got some "new"

lifter guide plates at the wreckers too that measured better.

 

Ok, so I got the new cams in and it all back together and it wouldn't start. What??? Just seemed to spin around and around. After cranking it for a little while there was this very loud bang, like an explosion. I thought for sure my engine was toast and I was like, oh well, I tried my best. A buddy of mine who was there said it sounded like it came from the exhaust manifold. Things didn't actually seem too exploded though and soon I found the problem. I had the ignition timing 180 degrees out of phase because I'd had the engine at #4 TDC when I put the distributor in. I don't recommend this. A bit later I was under the truck and found that my (brand new, I had replaced it as well) muffler was exploded open. Litterally blown open. That was the explosion. Unburnt fuel in the exhaust was finally ignited by a spark when I was cranking it with the ignition screwed up. So, another new muffler went in.

 

Ok, so, all good now right? Well, not quite. Things seemed to be better in general, but the engine would miss sometimes. At this point I had new plugs, wires, rotor and cap so I figured the ignition should be decent. There was also, AGAIN, a tapping sound from the passenger side head. So, off came that cover again. My mind was blown away when I found one of the valves was stuck down and the rocker was all loose. I tapped on the valve with a hammer and it popped back up, but I figured it was probably bent up from hitting the piston. I had no idea how it could have been stuck. I bought a leak down tester kit and rented a compressor and found that a lot of my valves were leaky.

 

So, I pulled the heads. Turns out the valves were all rusted in the guides. My new valves. What seems to have happened is that when I had the machine shop do my valve seats, they installed the valves, because they were lapped to match, but they didn't lubricate them! Then, when I shut the truck down for a month or so to replace the cams just after that, they sat there and rusted and one of them got totally stuck. Thankfully it wasn't bent at all. So I cleaned up the valves and guides and seats, lubricated it all and put it back together again.

 

At some point around this time I found that the rear (thankfully disc) brakes were seized, so I replaced callipers, pads, rotors. I decided to also look at the front, and despite them being better, they were still basically toast, so I did callipers and pads and rotors there too. I also did some front wheel bearings and replace the parking brake cables (that was a pain since I broke a bolt and had to buy a close quarters drill to get it out, also you have to dismantle the mini-drum brake in the rotor).

 

Now, things were getting a bit better, but I could hear an air leak in the top of the engine. By pushing around on stuff I found it was at an injector to intake seal. So, off came the plenum again. Found I had a bent fuel rail (from some previous owner hooligans I guess) and I got another from the wreckers. Swapped my injectors over and I was back in business.

 

I also replaced a broken headlight, replaced the voltage regulator in the dash, replaced the drivers side door handle and lock, replaced front and rear sway bar bushings, and replaced the diff fluids and transmission and t-case fluids with all synthetic (MT90 for trans and tease). Replaced O2 sensor and cat and all exhaust gaskets. I also fixed the super noisy external tire carrier death rattle.

 

Now things were working pretty well, but a few weeks later my truck wouldn't start. It would start to turn and then it was like the engine hit a brick all and CLUNK. Nothing. Eventually I found out that my oil smelled like gas. I'd read about this on the forum here and yep, my #4 cylinder was full of gas. Engine couldn't turn over has it was "gasolocked". Sigh. I had torn an o-ring when I switched my injectors to the new rail. I was now suspicious of some of the other injectors, so I had them all refurbished at a fuel injection place, and replaced one of them that had a bad resistance.

 

Ok, so, what else could go wrong? Well, after I switched out my engine break in oil to some thinner stuff (5w30 synthetic). I found that when I was fully warmed up the oil light would come on at idle sometimes. I had installed an aftermarket gauge too and it seemed pretty darn low. Measured a little low at 3200 rpm too (the FSM spec is like 53 psi+). HMM. So I was worried about this and decided that one thing that could be wrong was the oil pick up tube o-ring. When I replaced it the new one didn't seem so great. So I pulled the oil pan. As you may know, this is rather annoying as you have to remove the front diff (gave me an opportunity to replace some torn CV boots). Anyway, got it off, but the o-ring seemed basically fine. I decided to be suspicious of my oil pump. I started blowing in the input port and seemed like there was air leaking out somewhere nearby. Not so good.

 

So, off came the timing belt for the zillionth time. At least I'm good at it now. Replaced the oil pump (a mechanic at the dealership asked me what it was, I guess they don't do too many wd21oil pump replacements around there). This seems to have solved the oil pressure problem. Hooray!

 

So, I think that's pretty much my story up to now. I did drive the truck up a pretty gnarly logging road last weekend. Someone else with a pathfinder had posted on the web that it was impassible, but I guess I proved them wrong.

 

Some stuff I still need to do:

 

-fix alignment better

-fix rear defroster

-fix abs

-fix transmission!

-replace front compression rods and weld on new bearing cups to hold bushings

-weld new sheet metal into two holes in the floor

-put in cd player and get the speakers to work

-replace windshield

-some bodywork

-install baby car seat (due in a month!)

 

Pics:

 

IMGP7053.jpg by sewebster, on Flickr

 

IMGP7056.jpg by sewebster, on Flickr

 

IMGP7058.jpg by sewebster, on Flickr

 

IMGP7061.jpg by sewebster, on Flickr

 

IMGP7062.jpg by sewebster, on Flickr

 

Truck came with some stickers that I'm not sure about. Probably should get an NPORA one sometime at least.

 

So, I put WAAAAY too much money and time into the truck now, but hopefully it runs for a bit. It was (kinda, sometimes) fun and I certainly learned a heck of a lot about pathys and trucks in general.

Edited April 9, 2011 by sewebster

[Slick]

wow. just..... wow. hopefully everything is ok now

[teixeira]

That's some serious work....