what is the opinions on the 3.1 gm

Status
Not open for further replies.
Joined
Apr 28, 2011
Messages
3,894
Location
missouri usa
i hear a lot of good and bad about these engines. i was curious what the opinion was on bitog
 
Last edited by a moderator:
Worthless junk motors. They have no power and depending on what year it's from it'll probably have/will have had/will develop Dexcool-related lower intake manifold gasket problems and/or head gasket problems.
 
The 2.8 was no stunner,and the 3.1 is just an enlarged version.The 3.4 is also related.When you stop and think that that family started out in March 1979 for the X-cars,you wonder why GM held onto it for so long...well,it was a 60degree V6 and not a 90 degree (so it was smaller for FWD applications),and it was cheap to make.GM always loved cheap.
 
Stepfather just sold 1994 Corsica with 3.1. As far as power it was plenty powerful for that car. It was before intake fiasco. He needed an alternator, tensioner bolt, belt, and motor mount in 180,000 miles. Coils were changed due to misfire, but new plug wires solved the problem. Otherwise regular maintenance on engine. Highway gas mileage was 35 + on some trips.

Heater core did need to be changed a few years ago. I lucked out and got to do that job.
 
i had one in high school and that was back when i thought i was cool. now i realize i was never cool but thats a different topic. anyway i used to do some dumb things with that car and it did great. my friend had a wrangler and i used to follow him in the trails with the corsica. but when i sold it it only had 131,000 miles it always ran good. i hear a lot of people say they are junk though so wasnt sure if maybe i was just lucky. OT but its easier to find a good running truck than it is to find a car for cheap for anyone who has been keeping up with my car shopping .
 
It's a reasonable stout little engine that fit nicely into a mid sized FWD car and less easily into a compact. The intake manifold gaskets were a huge problem, but with the updated gaskets it's very difficult to harm these engines. They came equipped with fuel injectors that may need regular cleaning if used for a lot of short trips.

It is a very good alternative to a 3800 series Buick engine. The light weight (assuming an aluminum head flavor of 3100) makes for a better balanced vehicle with better handling than using the heavier 3800 in otherwise the same vehicle. The 3100 also has far fewer "common failure" issues than a 3800, produces less vibration, and although it has less potential for maximum power output, it's power shows up at higher RPMs which helps avoid fragging the tranny.

These engines are not well supported for aftermarket performance upgrades. There are intake and exhaust manifold upgrades and cams, but not much else is readily available. Some performance parts such as rockers and connecting rods made for older Ford engines can also be put to use.
 
I think very highly of the 60 degree V6, also in 3.4, 3.5, 3.9. I actually prefer them to the 3800 in a lot of ways and maybe I'm in the monority. GM did drop the 3800 for the 60 degree before phasing it out.
 
Originally Posted By: MONKEYMAN
Stepfather just sold 1994 Corsica with 3.1. As far as power it was plenty powerful for that car. It was before intake fiasco. He needed an alternator, tensioner bolt, belt, and motor mount in 180,000 miles. Coils were changed due to misfire, but new plug wires solved the problem. Otherwise regular maintenance on engine. Highway gas mileage was 35 + on some trips.


The alternator is REAL easy to change and that is fortunate because they were short-lived for many years.

The rear plugs are a hassle. I found it easiest to remove the alternator and just reach behind the engine.

Belt tensioner flakes out early too. Replacements are usually improved over the original.

Coil packs.
33.gif
on the earlier models, some genius at GM decided to put them under the exhaust manifold.

Lower intake manifold gasket design flaw doomed a lot of 3.1s long before their time.

I would rate it with the Ford Vulcan 3.0 and Chrysler 3.3. The GM 3.1s had a few more glitches than the Ford and Chrysler, but they are external glitches. Not internal design failures. Overall the engine is durable. It has powered countless L and W bodied cars (and a few F and J bodies) for 100s of thousands of miles apiece.
 
Originally Posted By: Spazdog

Coil packs.
33.gif
on the earlier models, some genius at GM decided to put them under the exhaust manifold.



I forgot about that awful setup. Maybe my mind blocked it out because of some traumatic experience? 3 hours cool down time before a tune-up or Ouch!
 
my 2.8L Firebird was rock solid. 176,000 miles. 3 alternators, 4 starters, 3 ignition modules and 1 water pump. That motor was solid. I got pretty darn good gas mileage out of it, was able to hit 120mph all day long. Yeah, it took a bit longer, but fact is it did it and it never complained. I didn't have dexcool in 1989, I used Zerex Maxlife antifreeze at 112k.

my Mom had a 3.1L Chevy Beretta.. that motor was on the loud side, but it could keep up with anything. Had dexcool, but never had an intake manifold gasket leak. She sold it at 70k to a kid who drag raced 2 mustang 5.0's and won! of course tossed the tranny, but didn't blame us for it! Gave him a bottle of Greased Lightning Trans treatment and he was good for another year. But he junked the car after (the guy was a friend of a friend). It had a lot of guts in it, climbed steep grades like it was nothing.
tuneup and belt replacement was a . But a bottle of injector cleaner every oil change, no big deal, I didn't even put synthetic oil in it. I did use Valvoline WB though and a larger oil filter.
Oh.. replaced the coolant temp sensor and yes, 1 alternator.
All in all, it wasn't a bad car.. just hated the 2 doors.
 
I have a '92 Lumina with the 3.1L (not to be confused with the later 3100).

Decent economy on the highway (~28MPG), Lousy economy in town (15-18MPG). More of the way the vehicle is geared than the fault of the engine.

Pros:
1. Has been bulletproof for 180k miles.

2. Maintenance is easy.

3. Not difficult to work on IF you take your time.

4. Timing chain (see below).

5. Parts are cheap and easy to find.

6. No issues with LIM gaskets.

Cons:
1. Leaks oil from crankshaft snout/front cover.

2. Leaks oil from oil pump drive. Easy fix on a 3.1L (get the o-ring from GM, not aftermarket). On 3.4L, fix requires rear cylinder head to be removed.

3. Leaks oil from oil pan rail.

4. Leaks coolant from heater pipe at water pump housing (gasket failure).

5. Requires engine to be rotated to access anything bolted onto the rear cylinder head. This includes spark plugs. Removing the alternator is helpful.

5. Timing chain replacement similar to SBC. Have to drop the pan to remove the front cover. PITA and future leak risk.

6. Coil packs and ignition module ARE easy to remove. They are a PITA to re-attach to the engine. To help line everything up, it helps to safety wire the bolt that's closest to the oil filter adapter to the coil bracket before lining everything up. It also helps to leave off the right-most coil pack and bolt it on AFTER the bracket is attached to the engine.
 
I had one in a 98 lumina, the engine was good for power and decent mileage. It was very cold blooded though. There was a few times at 0F it would not start sitting outside. Had to use ether to get it started a few times.
 
Wife had a 3.1 in her 93 corsica. 29-32 MPG with a 3 speed tranny and peppy and smooth. Leaked oil at 200k miles from lots of places, the worst probably the infamous distributor blockoff o-ring.

I had a 3100 in a 2000 century, not nearly as nice. Rattly, 24-27 MPG. I think the piston slap was so bad the knock sensor was pulling timing.

Also had a 3400 in a silhouette van, same 24-27 MPG! This was a short wheelbase van and was probably pretty light weight, the torque and gearing made it pretty spunky!
 
Originally Posted By: EricF


my Mom had a 3.1L Chevy Beretta.. that motor was on the loud side, but it could keep up with anything. Had dexcool, but never had an intake manifold gasket leak. She sold it at 70k to a kid who drag raced 2 mustang 5.0's and won!


How does, what essentially is a Corsica 2 door automatic, happen to stay with V8 Mustangs?
 
Last edited:
Originally Posted By: EricF
my 2.8L Firebird was rock solid. 176,000 miles. 3 alternators, 4 starters, 3 ignition modules and 1 water pump. That motor was solid. I got pretty darn good gas mileage out of it, was able to hit 120mph all day long. Yeah, it took a bit longer, but fact is it did it and it never complained. I didn't have dexcool in 1989, I used Zerex Maxlife antifreeze at 112k.

my Mom had a 3.1L Chevy Beretta.. that motor was on the loud side, but it could keep up with anything. Had dexcool, but never had an intake manifold gasket leak. She sold it at 70k to a kid who drag raced 2 mustang 5.0's and won! of course tossed the tranny, but didn't blame us for it! Gave him a bottle of Greased Lightning Trans treatment and he was good for another year. But he junked the car after (the guy was a friend of a friend). It had a lot of guts in it, climbed steep grades like it was nothing.
tuneup and belt replacement was a . But a bottle of injector cleaner every oil change, no big deal, I didn't even put synthetic oil in it. I did use Valvoline WB though and a larger oil filter.
Oh.. replaced the coolant temp sensor and yes, 1 alternator.
All in all, it wasn't a bad car.. just hated the 2 doors.


The Beretta was a 16 second car. Was he racing pre-1986 5.0's? Because otherwise I call [censored].
 
I just sold my 2002 Century with 134K and the 3.1 was a great engine.
I did an IMG replacement at approx. 80K as a PM.
They designed it with only 4 bolts and a plastic gasket (which was ridiculous (GM beancounters saving money again).
With the proper gasket (Fel-Pro PS and new bolts) this motor could run forever.

It got over 30 MPG on the highway but dropped to about 22 around town.

My 2002 Century was an EXCELLENT car.
 
Status
Not open for further replies.
Back
Top