3.4L DOHC/Twin Cam
 

Ok so I have a 93 Lumina that I was talking with my fathers mechanic about, because there is a power steering leak and was wondering how much he would charge to fix it. So anyway, he was saying that the 3.4 in these cars are junk and are always causing problems. He was also going on about how hard they are to work on which is obvious.

I guess I had never really heard that they were junk. So now my dad wants me to get rid of this car because of the "problems" that we are doomed to have I guess. Its only got 83000 miles on it, but it sat around a lot of its life these past few years so there is still a lot of work that needs to be done. It idles high when it is started, then idles normal after warming up.

Guess I was just wondering if this mechanic just got a bad one, or if I just havent been listening well enough about these engines. Just a chit chat about the reliability of the 3.4.

dunno if the 93 Lumina has the same 3.4L as my 03 Monte Carlo but mine is been honestly problem free since new just as long as you keep up with the maintenance, i have 150,000 and honestly to this day not a single thing like sensors, internal or external mechanical parts had failed yet, so if i had to rate the GM 3100-3800 series engines id give them a 9-10 out of 10

the 93 lumina has the same 3.4l v6 as the 95-97 z34 montes i believe. reliable engines with the lower intake issues that the 3.1s have. im sure others with much more info will chime in soon enough.

The 3.4 in that Lumina and the 95-97 Montes is a DOHC engine and quite different than the 3100/3400's. I'm not familiar with their reliability, but I do know they can be quite difficult to work on. mrl390, a member here, has one and probably knows the most about them. I know when I look at 5th gen Z34's, I tend to look at '98 and '99 models, because they have the 3800 in them which I am much more comfortable with. If I bought a 3.4 DOHC car, it would have to be in exceptional condition. This is not a knock on the engine, more on myself for not knowing how to work on them.

If you have the lq1 engine mine been good Haven't had any problems from the engine. I have 112k miles on it too

I've heard they are problematic but idk from experience.

If yours is a manuall then its rather rare. From what I read on here awhile ago.

Ok who ever that mechanic is, dont go back. people who say these engine are problematic and difficult to work on are ignorant.

this engine is very rare when you look at their numbers compaired to the 3100/3400 series and same for the 3800's these engines are infact very strong long lasting engines. mine went for 225,000 hard driven miles. I think that maybe most mechanics have never seen it before and dont want to take the time to read the book or learn.

people use them in fiero's a bunch and throw turbos and make 300-350 hp to the gound and the engine takes it no probs.

yes that lumina with 5spd is even more rare. if you want to get rid of it i know a few that will take it off your hands so dont go scraping it.

the issues they have are:
-lower intake manifold vaccum leak. both the 3100 and 3800 have this issue and it is easyer to change the gasket on the DOHC then these other two.

-Oil pump drive shaft leak... under the Throtlebody on the block near the trany there is a metal plug about the size of a silver dollar that leaks oil. you can lift it up and pack Quick steel epoxi or jb weld and seal it shut.

-Timing belt. this is the biggie. service intervals are 75,000 miles. you can take the access cover off and see the belt. if it look like a lot of shavings like more then a hand full and or the belt is less then 2" wide or is not tight then it needs replaced.