Scion xB Forum banner
1 - 3 of 11 Posts

Registered
Joined
469 Posts
08 xB. 142,500 miles. "Loaned" it to son/DIL for 3 years (son is NOT mechanically savvy). Suddenly developed rough-running - comes n goes - oil consumption up - "misfire" and O2 sensor codes. We retrieved the car, as their local stop-and-rob Toyota dealer quoted "engine-replacement - $10,000" without investigating anything. Thinking it was coil-pack - I asked son to swap 1-2 - now misfire on 1 AND 2 (he did that before we were able to pick it up). Got it home, and compression test found #1 with NO compression at all. Hmmmm, must be stuck valve? Removed rocker cover to check. Intake cam - inner flange at main bearing boss - doesn't look like the exhaust cam. The flange - i.e., a machined part of the cam casting - BROKE OFF from it's position on the cam and wedged-open one of the intake valves in #1 (looks like a big thick "washer" flopping around on the cam). My suspicion is that it was a defective casting. There is nothing preventing "endplay" now, except the timing chain tracking with the tensioner and the exhaust cam sprocket (of course we're not driving it). Anyone ever replace cam(s) without removing engine? I'm up for trying it if I don't have to horse the engine out of there.... View attachment 80847
First off, Welcome to the club! This is over my head but I will say: Yes it's easy to replace the cams- just do it with the stock ones from a Junkyard- because everything is right on top- 1.8 Tony or Superbee44 ( knowledgeable club members) probably have done this a few times.. They may chime in. And yes $10 grand for a motor is ridiculous, you can get them for $900 to $1,200 low miles at a JDM motor sales shop.... Others should chime in.. Again Welcome.
 

Registered
Joined
469 Posts
Thanks for the come-back - being a NOOB, that encouragement is helpful. Late yesterday, wife found a pair of cams online for $80 (she's real good at interweb stuff), and I found a pretty good how-to video, so I might try it (I'm 70 years old with gimpy knees, so that sitting on the ground and reaching past the wheel to get to crank and chain might cause me to farm it out). Wife's really disgusted with the kids - car looked brand new when we "loaned" it to them - now dents and scratches and nasty innards, and not very attentive maintenance...but she wants to drive it again.
Well I had my Dad's 1979 Impala station wagon and I drove it into the ground not caring about it because my Dad owned it and paid for all the repairs back in 83. Kids seem to learn to take care of things when they have to pay for it.. 馃槅 Let us know how it comes out!
 

Registered
Joined
469 Posts
Tony - thanks for the how-stuff-gets-damaged assessment. While waiting on the used cams and bearing-caps, I got everything disassembled and inspected. Caps and bosses - except for the tore-up one - looked pretty good for 142K, at least I thought so. Chain wasn't side-to-side sloppy at all. Followers didn't appear to be marked up - just some discoloration - even the one that had that broken-off flange wedging the valve open (#1-intake, closest to the cam-phaser). I only used the replacement intake cam, and did a "fingernail" scratch test on the bearing journals on both it and the original exhaust cam - used narrow strip of 600-grit emery paper on each - counting see-saw motions 3 times around each one until they were smooth. Used an entire can of brake cleaner on/in each one to clean them, and another couple of cans on the head and chain. In the well next to #1 follower, I used a magnet to retrieve probably 1/4 tsp of iron bits. Got cams in, tensioner snapped in, oil changed (made sure chain got a good dose too), and then cranked it for 15-20 seconds to make sure oil was getting to the head OK. Cam cover back on - coils - and then cranked for a run. Happy to report the initial "stumbles" quickly disappeared and it ran smooth within a few seconds.

I'm just guessing... I found a Pennzoil filter on it - I know the kid would in no way have changed it himself, but I don't know what stop-and-rob quick-lube place uses those products. I noted that the oil that I was blowing out of the wells in the head, with the brake-cleaner, sorta' reminded me of the juice from prime-rib - little globules of fat swimming around - the brake-cleaner didn't really "dissolve" it as much as it just loosened it up and floated it away. The drained oil was also NOT 0 or 5W - anything - it was THICK, and could have very well been NOT synthetic. I'm guessing that was more likely the cause of this problem - too-thick oil, run too long, and maybe made from dead dinosaur skin instead of re-constituted "gas." Will change the oil after a few hundred miles, and replace with 5W-something and a WIX filter. I saved the old filter - will see if Hobo-Freight has a filter-cutter - would like to see what's in it.

Thanks again!
This is very interesting!! A mechanical noob like me is just eating this stuff up!! Thanks gentlemen
 
1 - 3 of 11 Posts
Top