question for mechanics

[KansasFal]

just wanted to ask some of the local experts what they think of GM's 3800 series II engine, I have heard some say it is one of the top 10 production engines made.
please give me some feedback.

Thanks

[Noah Zark]

IMO, the General must have screwed up because the 3800 is a great engine, in certain years and vehicles. It has an excellent rep with local independent mechanics, one of which worked for 15 years at a Pontiac dealer. He points to one customer with over 250K miles on a 3800.

The Series II had a boost in output over the earlier 3800 and the 3.8 before it.

BUT, as automakers are wont to do, GM started de-contenting the 3800, and around about '96, they switched to a plastic intake on some vehicles, if not all. That thing will warp or otherwise deform with time and heat and start leaking fluids from one circuit to another, oil to coolant, for example. Excluding the cheaper plastic intake and the cost of replacing it usually after warranty and boren by the owners, the rest of the engine is pretty tough.

Certain styles of the solid state coil packs are prone to frying, giving you ignition on four of six cylinders.

But holy cats, my '92 3800 Series I (one) has 78,000 miles (and an aluminum intake!) and still gets 28 MPG at 65 to 70 on the I-road, 32 if I slow to 60-65.

Noah

[KansasFal]

Thanks for all the info Noah, I have a 1995 Pontiac Bonneville SE with 135,000 and its still a great vehical.
All I have had to do to it so far is put on a new water pump besides the normal tires, belts and plugs.

I have been hearing alot about synthetic oil like "Mobil 1" is it really worth the extra cash to have that in the crank case.
I heard a Mobil 1 commercial the other day say that after using Mobil 1 for 200,000 miles the engine showed no signs of internal wear, now that sounds to good to be true.

[Noah Zark]

Kansas:

I would hesitate starting to use a synthetic at this late date. There is a ton of documented incidents of seal leakage immediately following a switch to synthentic on high-mileage engines. Some have done so with success, but many more have not, and I would personally continue using what you have, with frequent 3K to 5K changes with filter.

Yours should not have the plastic intake, congrats.

Noah

[ginman999]

I had a 95 Bonnie with a 3.8. I fixed my intake with JB weld.