LIM/UIM Repalcement Commentary

[96LSS]

After putting it off longer than I should have, I removed the UIM & LIM off my '96 LSS N/A 3800 (excellent instructions in the Techinfo section, BTW). The car had just passed the 100,000 mark, was leaking oil and starting to consume anti-freeze. The previous owner had the UIM changed by a dealership in '07 but the LIM had never been off of the car and it was still running dex-cool. Upon inspection, it was apparent that the LIM gaskets had started to fail (as described in the forums) and the replacement UIM either wasn't torqued properly, or was warped, because that was the source of my oil leak. Overall, this isn't too bad of a repair - everything is pretty accessible. However, I have to say that I'm pretty disappointed with some of the obviously poor GM design issues behind the need for this repair in the first place. My opinion is that the 3800 is one of the great motors out there and it seems like GM should have known better. For less than a couple of dollars per unit, they could have prevented this problem up front. Oh well, I guess that's why these cars are so inexpensive - mine was a mint, one-owner local trade-in with 82,000 miles, absolutely loaded and I picked it up a year ago for $3600.

The APN UIM kit and GM LIM gaskets are on order, so I should have it back on the road in a week or so. I'm also replacing all four struts with sensatracs and getting rid of a noisy power steering pump while I've got it all apart. Should be good to go for several more years once I get it all back together. Thanks again for all of the great info on the forums.

Jim

[Jrs3800]

We are glad to have been of help to you... Its info that we learned over the years and continue to update as new or improved parts become available... Back in the earlier days we started seeing a lot of failed upper intakes and issues with the lower intake gaskets... we learned quickly what a problem this was and why and then started to watch the failures roll in... From that point we thought it was time for the 3800 II owners to know what problems they will face...

The articles have been updated and or added to as time went on..

You are a prime example of what we were trying to accomplish..

Have to thank you for your praise... I appreciate it as much as our Gearhead team

[bobfather99]

The 3800 is an excellent engine, once you get the UIM/LIM work done.
Powerful and pretty economical for a full size car engine.

If your car has Dex-Cool, I would recommend flushing it, replacing it with green stuff/Prestone "All Makes" coolant.

Drain the oil ASAP,
do your repairs,
buy any el cheapo oil/filter and run 500 miles, (I ran Advance Auto house-brand oil/filter)
then change oil/filter with the brand of your choice.
I did my engine work when the weather was warm, so I ran Chevron Delo 15w40/PF52 oversize filter for 3000 miles, just to make sure I got out the last bit of gunk.

Engine still running sweet, just turned 172,500 miles today, started no problem with temp of -6 this morning.