1981 Oldsmobile 98 Regency 5.7 diesel from North America


A great, smooth, unusual car, kind of lost in the modern world, but still survives


The car is 31 years old and has truly been a great car. Very few cars even last 31 years.

A few power windows over that past 31 years.

Transmission leak at the front seal.

Engine rebuilt in 2000 (the car was 19 years old) at 75,000-miles. Not unusual for this new "Diesel" technology that GM rushed to market in the late 70's (oil leaks - low compression, coolant leaks, getting harder to start), but the engine never actually gave out.

Rebuilt engine has head studs, solid copper head gaskets, and a beefed up mains. I added a water separator as well.

Injection pump rebuilt in 2000 also. Was leaking a small amount of diesel fuel due to old seals.

Glow plug system converted to push button activation with all new glow plugs several times over 31 years.

2 alternators in 31 years.

4 or 5 water pumps in 31 years.

1 fuel pump - I converted it to electric in 2000.

I drove this car to work for 20 years. Just down the road. It always started (no matter how cold) and never had to be towed once.

General Comments:

The car has been great. It can get up to 33 MPG on the highway at 55mph if driven like a Granny.

In town with the A/C on - it will get 17 MPG or more. By the way, the A/C is still 100% original with a minor leak - 1 pound of Freon per summer.

The old car drives so smooth and the cloth pillow top seats are amazingly comfortable. The car is by far more comfortable than any car built in the past 20 years.

The diesel engine is a bit loud, but these cars have become so rare, that at gas stations people always walk up to talk about the car, once they hear the diesel clatter.

The power steering is so easy to turn, and the car drives like a real boat. The ride almost makes you feel like you are on water, as you can feel no road bumps whatsoever.

The car is probably not up to speed in today's fast paced "rat race" world, but it is sure nice to drive on a Sunday.

It is a great car from a past time in automotive history in the United States.

By today's standards the car is under-powered, but we have to remember why the car was built during the energy crisis, the car was built for MPG - not horse power. Jimmy Carter was still in the White House when this car was being built.

I still enjoy driving the car, and will never sell it. I love the smell of the diesel exhaust along with the sounds.

Would you buy another car from this manufacturer? Yes

Review Date: 22nd May, 2012

22nd May 2012, 06:54

Wonderful cars, great review. Some people have bad luck with the diesels - I've had a couple with the gasoline 307. What I've always wondered, was if the diesel went out, if it would be prohibitively expensive or difficult to change out the engine for the 307 gasoline?

28th May 2012, 23:13

Converting from diesel to gas requires that you actually have to physically remove the engine, and replace the whole engine with a gas engine.

You can use a diesel block and put gas heads and intake on it, and build one bad engine with 500+ horsepower. The diesel blocks are very thick and tough.

Most all GM RWD cars will easily exchange engines and transmissions, as they all share the same bell housing bolt patterns and engine mounting locations. Even the exhaust manifold bolts are in the same place.

Going from diesel to gas will require you to also change out the braking system, as on the diesel cars, the brakes were totally hydraulic - not vacuum assisted.

This conversion is fairly simply, and was done on a daily basis at most shops in the mid 80's. Today most shops have moved on to a younger employee pool, and I doubt that these kids even know how to tune a carburetor. I don't even know if they even teach carbs in AES schools anymore.

I remember it was hard to find a gas 350 or 307 to put in place of a diesel. 95% of people simply converted to gas, and didn't even want another diesel.

The 5.7 L GM diesel can be made to be fairly reliable.

You must start off with the DX block - 1981 or newer block. You should put in high performance head gaskets with super high strength head studs. You should add a water separator along with several fuel filters.

Always let the car warm up for at least 3-5 minutes - even when warm outside before you really get on the acceleration very hard.

In the cold winter time - you should let the car warm up for 7-10 minutes before pulling out of the drive way.

Always use a super high quality oil, and only use an engine oil that is specifically made for a diesel engine, and change your oil every 2000-3000 miles. Change your own oil if you can to make sure it is done right. I have seen shops put standard oil into these engines back in the day.

The main problem with these cars in the 80's, was that people didn't let them warm up. The diesel fuel back then was so full of water and dirt. The engine oils were prehistoric in terms of high quality lubrication and protection properties. The shops really had no idea how to really work on these engines. They even reused stretched out head bolts when replacing a blown head gasket - well the stretched out bolt was why the gasket blew in the first place.

I have seen many of these engines last 200,000 miles or more, and that isn't bad for a car of the late 70's and early 80's. Most gas engines back then were lucky to hit 100-125,000-miles.

With today's modern fuel injection and great oils, along with super clean fuels - all cars will typically go 200,000 miles with little to no problems - even cheap economic cars are better.

Just because of how old these cars are today, I wouldn't recommend one as a daily driver. Any 30 year old car is too old for a modern driver car. You don't have ABS, air bags, safer crash designs, etc. Also the car is old - the heater core is rotten and could blow out any second, suspension parts are old, on and on and on.

Don't get me wrong on the safety- I did see a few years ago a big early 80's Buick Electra get hit head on by a brand new Honda Civic. 40 mph. Both were 4-door cars. Both cars had mangled front ends and the Civic even had a bent up roof. The older lady in the Buick was not hurt. The girl in the Civic was bleeding all over the face - probably from the air bag, and her left leg had a protruding compound break between the knee and hip. When they hit, the big Buick slammed the Civic to a dead stop and then pushed it backwards 30-feet. I was gassing up my car and heard the old lady hit the brakes with tire squeal and blue smoke. The girl in the Civic was texting and never even hit the brakes. The crash happened right in front of me. The sweet steam of the antifreeze spewed out and I could taste it on my lips from the back of my car.

So when I say not safe - I am speaking in relative terms - not absolute.

29th May 2012, 11:27

"Most gas engines back then were lucky to hit 100-125,000-miles."

Really? All my V-8 American cars 60s, 70s, and 80s, and those of all my friends, family, and acquaintances routinely made it to 200-300,000 miles. At 100-125,000 they were just barely broken in.

Loved your story about the Buick/Civic crash. The big old ones were far safer. ABS and airbags are nothing compared to mass.

30th May 2012, 17:07

I agree.

81 Olds Cutlass, 185,000 miles (before the odometer stopped working).

84 Grand Prix, 210,000 before the Buick built V6 got tired.

85 RWD LeSabre, over 140,000 trouble free miles before it was sold.

76 Ford Elite, I really don't remember this car, but I always hear about it hitting the 200,000 mile mark.

The Grand Prix was my 1st car, and I would give anything to have one again. The others belonged to family members and were excellent cars.

Not to say anything domestic from the late 80's - the 90's were bad. We also had an 89 LeSabre top out at 175,000, and my current 96 Town Car is rolling along at 165,000, and still runs like new.

25th Feb 2013, 16:47

You do not have to change out anything on the brake system. The diesel brake system is ran by the power steering pump. Bolt the original power steering pump to the gas engine, and you're good to go with no problems.

1981 Oldsmobile 98 Regency Brougham 307 V8 5.0 Liter from North America


Tough old cruiser


Speedometer cable broke at around 191K.

Oil pan starting to leak.

A/C compressor replaced and recharged/retrofitted to R134 coolant after original system finally failed in 2005.

Water pump at 212,000 miles.

Replaced all 4 ball joints; the only thing on this car that I think is truly hard to work on.

Paint is starting to crack and fade after nearly 30 years in the desert southwest.

Rebuilt carburetor in 2006 due to rough idle at startup or in cold weather. The gaskets were old and cracking, and the choke was sticking and needed a good cleaning.

Replaced both valve cover and head gaskets around 200K miles. They weren't bad yet, but usually around this age/mileage is when most cars of this vintage start to really lose oil control.

Replaced rear main seal last week, and timing chain as a precaution.

Replaced both u-joints at 210K. One cracked one day at 70 MPH, and I felt like I was in a jackhammer on wheels. This is the only time this car came even close to stranding me. I was able to limp the car at 30MPH to a repair shop.

Replaced exhaust from the catalyst to the rear at v213K.

Front passenger power window motor failed at 215K, replaced with one from a junkyard for $10. Left rear window motor is deathly slow and probably headed in the same direction.

I installed stiffer coil springs and firmer shocks last year to help get away from the bouncy/boaty ride a bit. The car handles and corners much better now.

General Comments:

I inherited this old GM giant from my grandparents after he died and she was moved to assisted living in 2002. Like most younger people, I had no interest in keeping or driving an "old man's car" or a "land yacht", but like most of the reviews I read on here, it didn't take me more than two weeks to fall in love.

The car is black with black vinyl top, and red velour interior. Sitting in this car it's hard to tell it's almost 28 years old. GM knew a thing or two about fit and finish back then. Time has taken a bit of a toll on the paint, but no rust in sight. My grandparents purchased this car new in the spring of 1981, and ironically I was with them at the time for some reason. I was about 5 years old and was fascinated by the new Delco electronic tuned radio and cassette player; it was the first time I had seen one up close. Grandpa let me play with it and I found a station that was playing REO speedwagon's "I'm gonna keep on loving you." This song mysteriously came on that same Delco radio in 2005 just a few minutes after breaking 200,000 miles.

This car has survived two trips from South Dakota to Georgia and three from South Dakota to Arizona. It has no problem achieving close to 22 MPG at 75 MPH on the highway, sometimes higher, sometimes lower depending on road and weather conditions. I use cheap 87 Octane gas and cheap oil from Wal-Mart, and never a hint of trouble. No oil usage, no blow-by.

Before anyone accuses me of driving a gas guzzler, you had better look at all the yuppies driving full size SUV's down the road at 75MPH and 14 MPG. My cruising range is anywhere from 320 to 510 miles with my 25 gallon fuel tank, assuming I add 21 gallons at each fill-up.

It's no drag racer, and a bit of a slug from a dead stop if you really want power. But mid RPM and high speed cruising is where the engine and gearbox shine. Its tall 2.56 gears are meant for fuel economy, and it has no problem keeping up with any modern car in the hills and mountains. Even when climbing through the Rocky mountains, I've only had the coolant temp gauge touch 200 degrees a few times, usually on a hot day with the A/C blasting. It's so smooth and quiet sometimes I rev it when at a stoplight or roll down the window to make sure it's still running.

Next summer I plan on having the car professionally repainted and re-rustproofed. The car has never touched a salty road and I plan on keeping it that way.

Would you buy another car from this manufacturer? Yes

Review Date: 19th September, 2007

8th Sep 2008, 00:00

I have almost the same car as this, except mine is gold with a dark brown top. It's a Canadian model too, so no computer. It has nearly 250,000 miles, 90,000 of them nearly trouble free and put on by me in New Mexico and Arizona. I think it was well worth the $1500 dollars I paid for it 10 years ago. Its so smooth and quiet, still no oil leaks yet. No rust yet but the paint is looking pretty bad. I treat the vinyl top once every few months and it looks brand new. I don't care if gas gets up to $10 per gallon, I'm never getting rid of this car. It's been to good to me.

22nd Apr 2012, 22:31

Wow, your Olds actually has the rare little rectangle temp/battery/oil pressure gauges? I am jealous, my '84 Delta doesn't have them, and I am told they were rare when these cars were new.

24th Apr 2012, 16:39

I used to own an 84 Delta with those optional gauges. They were actually pretty useless, mounted way below your line of sight in the instrument panel, and too small to be easily read when you did look at them. They looked exactly like the afterthought that they were; no wonder they were rarely ordered.

1981 Oldsmobile 98 Regency 307 from North America


Must have been a heck of a car in it's day



A/C compressor.

P/W rear.

Door handle broke passenger side.

General Comments:

Purchased for $300 as a third car for a spare. Now we drive it as #1 car.

Interior in excelent shape for the age.

Handles very well.

Gets excelent mileage for such a huge car, 24 m.p.g. Hi way.

Closest I'm ever going to get to a Cadillac.

We are planing on a new paint job, and keeping it as a classic!

Would you buy another car from this manufacturer? Yes

Review Date: 2nd August, 2002