Always been a V-8 guy so I have to ask for some help. Friend has a 1989 with the 3.1l v-6. He changed out the timing gears and chain, car wont start. He probably didnt set/check the proper gear alignment before he took it apart. Since he asked me about proper gear alignment after he put everything back together, it is reasonable to assume that he didnt verify alignment before removal. I did some research and I cant find a straight answer for replacing the gears assuming he disturbed the engine after removal of the gears. Time to check with the experts, how do I tell him to align the gears? Thanks, George.

 

It is basically the same as a SBC. Dot-to-dot (cam at 6, crank at noon), is TDC compression on #4. With both at high noon, TDC on #1.

#1 cylinder is right side of engine (opposite of SBC). Firing order of 1, 2, 3, 4, 5, 6.

RBob.

 

Thanks Rbob. I was reading the 88 shop manual earlier ( not a 3.1) and it showed the cam gear marks in both positions (12 & 6) and referenced #1 and #4 as TDC. I kind of guessed that they were showing either option, but they didnt state that so I thiught I would ask. Now I get to work on yet another V-6, my 2001 S-10 4.3 has an intake coolant leak.