99 Lesabre Diesel Swap
 

I did some searching and didn't find anything, so here goes:

I have a 99 Lesabre, good old 3800 v6. As much as I love the 3800, it's definitely not the best for fuel economy. I've been thinking about doing a diesel swap of some sort for years; my original plan was a 4BT in an astro van for my family car, but now I commute 84 miles round trip, so I was thinking of trying it in this Buick.

The 4T-65 will supposedly handle 240 ft-lbs, which is probably right around what a small 4-cyl diesel would produce, so I think the tranny will handle it.

My question, does anyone know of a 4-cyl (or less I suppose) diesel that uses the GM Metric bolt pattern? I have access to a lot of fabrication equipment if I need, but a direct bolt up would be nice as a 4-cyl is going to be longer end to end than the current v-6 that's in there, so the less length I add the better.

I think you are going to have a very hard time with a diesel swap retaining the transverse transmission. I am assuming you have looked at a new R2.8 from Cummins, which I assume is too big to be mounted transversely.

I don't know the bolt pattern of the new 1.6L from the Chevy Cruise/ Equinox/etcetera but those would require a computer and electronics swap to work as well. Not for the faint of heart.

There are a number of people illegally putting tractor and generator engines in vehicles, but even most of those are based on the availability of a bellhousing adapter as I believe most of those are SAE engines.

If the Buick is your primary driver I would suggest you get a secondary car to do a swap in, expect large amounts of downtime during the transition. I ended up just buying a diesel Suburban for my "swap" which was more of a "refresh", no title or legality issues.

-Edit: And my family has had 5 Lesabres/Park Avenues so I am familiar with the platform.

Pretty much the only diesel that I know of that shares that bolt pattern is the old Olds 4.3 v6 from the early 80's, but those are pretty rare and aren't direct injection, so they aren't especially efficient. S10's came with 4 cylinder diesels from Isuzu I think but have no idea what bolt pattern those are.

Another important consideration is the trans in your car is electronically controlled by the pcm, so you will have to come up with a trans control for it. Aftermarket trans controllers do exist, but something to keep in mind.

My suggestion for best bang for the buck would be a vw alh, but it would take a good bit of fab work to make it happen. Someone has one in a fiero, so I know it can be made to work.

I'd say a diesel swap is not the best approach. If the 3.8 cant hit the mpg numbers you want, you could always put in the 3.1 liter. Also, taller tires will improve the gearing since the 3.8 likely has plenty of torque for it.

Thanks for the replies.

As for a 3.1, I'm really not a fan of the 60 degree V6's. I may be trading this car off on an escort shortly, so that would help my numbers quite a bit. My wife wanted my work car to be able to carry the whole family if need be, and in the past 4 months since I got it that has happened exactly 0 times, so I may pull the trump card of cutting my fuel bill 30-40%.

If a vehicle swap turns out to be the better option - and I really think it is - then a whole world of thrifty, long-legged choices lie at your feet. 84 miles is a lot of distance to cover on a homebrew swap. I'm not trying to cast aspersions on your wrenching ability. But you don't see people swapping little diesels into old LeSabres, so you'd be wandering off into the engine swap hinterlands pretty much by yourself. The difficulties you face are going to be new to everybody, which means you get to be Patient Zero in trying to work out the bugs.

If you were trying to pull this off with a small truck you'd have plenty of experience out there to draw on if you needed it, not to mention more room under the hood and a broader range of engines to choose from. But this? Yikes.

If it were me, I'd sell the LeSabre in favor of a good used hybrid.

A Mirage is a newer cheap fuel efficient option
Prii have come down in price and seat the whole family
A classic Insight can’t be beat on mpgs
Older used Volts start at $6000

Also that Buick of yours should turn high 20’s low 30’s highway
Maybe a manual transaxle swap would be a better option than a 1980’s Diesel

I'd love to put a manual in it. I don't think there's one that fits though? This is my first automatic in 7 years, and it's driving me crazy only having two pedals.

As for a hybrid: I live in the frozen wastelands of ND (it got above 0 degrees in sunlight today for the first time in nearly 40 days, and we've seen several days of -65 windchills), so I'm hesitant to trust a battery in that cold. I've also seen the damage on of those big Lithium batteries can do if it fails the right (wrong?) way.

Call me paranoid, but I'll stick with full internal combustion drive until the hybrids have been proven out more. Plus I usually run $1000 or less cars, and hybrid batteries alone are 3-4x that budget.

Most likely plan is going to switch to a little four-banger with a 5-speed. That's what I wanted in the first place but the wife pushed for a car we could all fit in (even though she has a minivan). When I did the math on what we could save a month if I could get a car to hit 40 MPG I think I persuaded her otherwise though.

An uncle of mine tried to put the same Getrag transmission fitted to some Opels and Saturns into a Pontiac Trans Sport with a 3800 V6. The problem was having to CNC-ing a new flywheel which was hard to get properly balanced.


I'd not disconsider a Diesel. BTW the Cummins R2.8 is supposed to fit into most applications for which a 2.2L 4-banger turbodiesel would be called for, so it may serve you quite well. It's already used in some space-constrained applications such as those forward-control vans in Asia (mostly Chinese copies of the previous-generation Toyota HiAce), so it seems like you wouldn't get too many clearance issues to overcome.

Buying a TDI Jetta would be a lot simpler. Comfy ride, not terribly expensive to get ahold of, though maintenance might kill ya.

As to a diesel swap...if you really want to go that route...assuming GM makes diesel engines with the same bell housing pattern as a 350, you can get adapter kits for chevy V8's to the metric bell housing. Of course, unless you find a used one, it will probably cost more than the car is worth.

Since it's no easy task, the sane route is to buy something that already does what you need of it and call it a day.