Hi, I have a 2003 Isuzu Rodeo 2WD, V6, 3.2L
I had a bad coolant leak and located the problem that was a bad rubber O-ring on the heater bypass hose. So, I tore down the intake manifold, replaced the O-ring, new manifold gaskets, and new thermostat, put it back together and decided to try and locate a squealing noise that recently started occurring as well. Replaced drive belt that had some wear and the idler pulley that had a ceased bearing in it. Drove it for a week just fine but I noticed a gurgling sound in my heater core, so I figured it had air in the system and needed burped. To no avail, I couldn’t get all the air out, further investigation I found another small leak coming out of the weep hole in the water pump, hence why it wouldn’t burp.
I replaced the water pump and a new timing belt. Did the timing by the book, meaning I had the number 2 piston at top dead center, the crankshaft pulley and the crankshaft gear with the v-notch in the 3 o’clock position lined up with the “I” stamp on the oil pump. Rotated the RH cam shaft several times until it sprung into place on the timing mark. Rotated the LH cam several times until it landed on the threaded bolt hole, and then rotated it an additional 90 degrees to line it up with the timing mark on the valve cover. Put new timing belt on with perspective marks, put crankshaft pulley back on and locked it down, pulled pin from tensioner, put number 2 spark plug back in, hooked up battery, started vehicle briefly. Check engine light is flashing and vehicle shakes, put it in gear to put a load on it, shakes more and acts likes it going to stall but doesn’t.
It seemed to me that it was a misfire happening or it could not be in time exactly. I took it all back apart and repeated the timing steps 3 more times and I am still getting the same results with the check engine light flashing and vehicle shaking. I did notice that my spark plugs were a little black, and the top white part looked burnt, it was about 6 months ago that I last changed them, not sure if this is a contributing factor and hoping that a valve is not bent, but that would be an extreme to the equation, but I’m not a professional mechanic by trade, hence why I am asking for your help. I’m stumped, if it’s in time to the “T” by the book, then why am I getting those results?
Unfortunately this engine is an interference engine. This means if the timing was set incorrectly the valves could be bent or damaged. Removing all the spark plugs and performing a compression test would identify what cylinders may be affected. It sounds like your timing should be good. A good rule of thumb is to rotate the engine several times, after setting the timing marks, and double check to make sure the marks still line up. I have seen the marks line up only to move one tooth once the tensioner is released. Sometimes you need to set it one tooth back so that when you release the tensioner it will line up correctly. Hopefully this is the issue and not valve damage.