: How Do I Get This Lucky?

02-23-09, 12:55 AM
So I bought another Catera over the weekend about 1000 miles from home, (00 Sport) get there to pick it up only to find it has a misfire which the local mechanic there tried to fix with some new spark plugs and new coil packs. Of course this wasn't mentioned but after driving 1000 miles I'm really not looking forward to driving back empty-handed so I begin trying to diagnose the car after 18 hours of driving and going on 35 hours with no sleep.

I first figure a headgasket with 106K on the clock, but the coolant was full and clean and so was the oil. I decided to take it for a drive after being suspicious that the oil was just changed (now thinking they were trying to cover things up). I take it out for about 30 minutes and find that it doesn't misfire under acceleration, only at idle. I come back and check the coolant and oil and find them both perfect. At this point I just figure it was a clogged or faulty injector on the #5 cylinder since the technician there swears he checked the compression on the #5 cylinder to be 145psi. So after being frustrated I offer $2300 and drive off to start the trip home, hoping the car is up for 1000 miles.

Sure enough, mile after mile was uneventful with no misfires on highway cruise, only when I'd stop for gas and come to an idle, and then for a few thousand feet after I'd pull off from a stop. About 800 miles into the trip I stopped for an hour or so to have breakfast, got back in the car, and now I was getting a constant misfire all the time. The car made it back fine and I checked the plug, coil pack, and swapped out the injector on #5 as I diagnosed it, then on the last start-up with the new injector it fired up with no misfire, then about 10 seconds into the idle I heard a rattling from the timing belt area and as soon as I did I began getting the misfire again.

I haven't pulled the timing cover yet but I'm assuming it's the infamous tensioner culprit. But wow, did I get lucky putting 1000 miles on a ticking time bomb! I haven't done any timing belt work on one of these, does anyone know the location of the tensioner that usually goes bad? It sounded like maybe the passenger's side, but was hard to tell.

02-23-09, 10:30 AM
Ouch!!!!!! Sounds baad bro!... so much misfire, I bet you fried that cat on the passenger side .... I have seen a Catalitic Converter cherry red from a Dodge Caravan... one of the injectors wasnt closing so it was running way too rich so the cat was struggling to keep up wtih it... similar thing to your car... fuel doesnt get burned so the Cat will try and clean up the mess but it can only do so much... I hope that you dont have a catalitic converter failure down the road... as for the misifire check everything... plugs, injector etc... I think it might be the intere coil on that side that is going bad.

See if you can swap it out with the other side and see if the problem continues to exist... otherwise 106K isnt bad but I would change that timing belt ASAP!!!...

Other then that post some pics I am curious to see how the car looks...

98 Catera
02-23-09, 11:16 AM
The tentioner is under the timing belt cover. I just had all that done to my car 2 weeks ago (timing blet, upgraded pulleys, tentioner...) you don't want to wait till it snaps! While your at it, change your serpentine belt, it will be off already for the timing belt chang out anyway.