joomanburning Posted January 13, 2016 Share Posted January 13, 2016 Hi all, New to forum. I just changed the timing belt on my 99 OBS 5spd, and now I have weak power/surging power up until 3,500, then it screams. Especially on hills, or when I'm at low rpm trying to accelerate. If I run it 30 min at highway speeds it's gone, I can put it in 5th at 45 on a hill and it seems just fine. Am I one tooth off? It seems like cams are loading up, engine responds like a timing retarded SBC... Help!! Quote Link to comment Share on other sites More sharing options...
joomanburning Posted January 13, 2016 Author Share Posted January 13, 2016 (edited) But again, it seems to go away after a long freeway jaunt..... Maybe vacuum? Edited January 14, 2016 by joomanburning Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 13, 2016 Share Posted January 13, 2016 Hi. I assume it was ok before the timing belt change? Did the previous timing belt break? Is it giving any codes/CEL/MIL? If it was ok before the belt change, and is now acting up, the easiest things to check would be making sure any stuff on the intake i.e. tubing etc is all connected back up, though '99 2.2L I think does not have a MAF but uses a MAP instead so it might not be that. One possible test to see if it is off a tooth is a compression test. Not sure about it seeming ok after a long jaunt but probably after it's nice and warmed up it is most efficient so maybe it just isn't as noticeable. Quote Link to comment Share on other sites More sharing options...
joomanburning Posted January 14, 2016 Author Share Posted January 14, 2016 Previous timing belt broke at idle on a cold night when warming up. I was right outside the car and there were no crazy noises. There was a quarter-inch strip of belt remaining intact all the way around with the teeth sheared off around the crank pulley, suggesting to me that the valvetrain simply stopped when the teeth sheared. All pulleys and idlers were intact and functional. I bought a timing belt put it on and it fired right up. I have not run a compression test yet for I didn't have a tester available to me, and the car was in a bad spot. No CEL, no codes thrown. I'm stumped because its fine above 3,500 rpm, or after it "warms up". It's like an old two stroke before it finds the power band. But then again SOMETIMES when I get into stop and go traffic AFTER a good freeway jaunt it'll start loading up again. Sometimes it runs just fine after such an event. At idle it purrs. When it's "warmed up" and running good it's super smooth. All of this suggests to me that I got lucky and didn't bend any valves... It makes power well and runs too good when it's "warmed up"... if valves were bent you'd think I'd get a consistent issue, all the time. Not something finicky-ish like this. Grr. Quote Link to comment Share on other sites More sharing options...
joomanburning Posted January 14, 2016 Author Share Posted January 14, 2016 I might add that this is the first time I've owned the car in the cold.... And the night the belt broke was the first night it got cold here ... Again, no issues or CEL previous to the timing belt breaking- car ran like a top. Runs just the same after it's "warmed up " Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 14, 2016 Share Posted January 14, 2016 (edited) Hm well that is an interference engine so there is a possibility one or more valves got bent a bit when the belt broke. You're right you may have gotten lucky and not bent any valves, but then again maybe not. A cylinder leakdown test would be the way to tell for sure. Edited January 14, 2016 by porcupine73 Quote Link to comment Share on other sites More sharing options...
joomanburning Posted January 14, 2016 Author Share Posted January 14, 2016 Right, but you'd think it'd idle rough and give me consistent issue had I bent any valves. I'll check compression, change fuel filter this wknd and see what happens. Quote Link to comment Share on other sites More sharing options...
KZCool Posted July 30, 2016 Share Posted July 30, 2016 Hey man, I was wondering if you ever figured it out. I have a 99 OBS AT. I've been having a similar issue but probably not the same reason. No time belt break, just suddenly threw a knock sensor code on a newer sensor. Replaced it with two other sensors and still giving me no power on low end until randomly after some hiway driving, but now no code. I've looked at basically everything I can thing of. I've got 290 k miles on this beast and I want to see that big 300! Lol Quote Link to comment Share on other sites More sharing options...
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