Opinion of 3.5l in Intrigue/ Aurora

The only problem I've seen is the balance shaft bearing (exactly like a camshaft bearing in a pushrod engine) starts to spin in the block, gets spit out and then the balance shaft chews up the block. At this point, you will be looking at a lot of money to pull the engine and possibly have the block repaired. We don't do it at the dealership, we just replace the engine. It's not a common problem, but when it happens it can be expensive.

The 4.0 liter engine is simply a smaller displacement version of the Northstar in the Cadillac vehicles. It has the identical problems that the Northstar has, water pumps leak, water pumps sieze and throw the belt and/or melt the plastic pulleys, head bolts pull out of the block, case half seals leak oil. Many of these repairs are very costly. And the engine needs to be worked on by someone who knows the engine and is familiar with repair techniques for these engines. Otherwise, you might just end up with scrap for a car.

Ian

Ouch! That doesn't sound pleasant. How frequent is such a problem? 1 in

I've heard the 3.5l burns a quart or two of oil between oil changes. Are there any other interesting characteristics?

Did this engine die with the Olds line, or is it being used elsewhere at GM?

Dave

gad wrote:

Well, it's probably not fair of me to comment too much. I work on them all day long and see all the bad things that go wrong. Example: We just had 2 Gen III 3800 engines come in the shop within days of each other...complaint: no/low oil pressure.....problem: spun camshaft bearings....identical problem in both engines. Are these one-off's? I guess we will see.

We have very few problems with the inline all aluminum engines... except the 5 cylinder. There seems to be some issues with the cylinder head design on that engine. We've had 2-3 engines with wierd misfires that ended up needing either all the exhaust valve springs replaced, or a new updated cylinder head installed. The 6 is pretty much bullet proof....we do almost nothing to them. I suspect the 4 will be like that too. The 4 cylinder Ecotec looks good. We have had a number of them come in with oil leaks....turns out to be porous blocks. Does GM replace the engines...nooo.....we epoxy the area of the block that is porous....yay for GM! The new generation small block (came out in 99) is by far and away the best engine GM has come up with. We rarely do anything to them. The cold piston noise is about the only real complaint. I've seen about 3-4 of them replaced since their inception. One had a crack in the block...some sort of manufacturing defect....another one, the oil pump cratered and took the motor with it. And then all the new VVT engines seem to be working quite good. We just got the first Impala with the 5.3 Displacement on Demand engine in it. We road tested it.....as far as we can tell, you cannot feel when the engine goes between the 8 cylinder and 4 cylinder mode. So there are a lot of good engines out there....and I think they are getting better. Most of the engines now have gone away from designs that allow coolant and oil to mix due to gaskets blowing.

Guarantee you that all other manufacturers have the same basic amount of problems. Ok, maybe not the Japanese ones, but they are still on a different level from the domestic manufacturers.

Ian

Thanks for the info. What models use the 6 cyl inline and the new gen small block you mention?

So far my 02 Impala LS (3.8 Gen II) is do>

The Trailblazers use the inline 6, the small block v-8 is used in the full size trucks, Corvettes, Cadillac CTS-V, and now it's starting to be used in full size front wheel drive cars.

Your car should have the updated lower manifold. They still can leak from the plastic upper plenum, but I haven't seen many of them do this.

Ian

Like the Impala SS, maybe?

Good to know. I had the recall work done (new fasteners and sealant). How about the EGR tube problem? Was that addressed at some point as well?

Yes, we just had one in the other day with the 5.3 Displacement on Demand engine.

Yes, the updated manifold that was available simply went right into the production engines. I think in 2001 it happened.

Ian