Does anyone have any advise with regards to mid 80's diesel's? Are they considered collectible or something to avoid. I'm looking at an 84 Oldsmobile 98 Regency Brougham with low mileage but may need some work. Thanks for any assistance.

 

They're classed as "rare, but not desireable". A small population of the Olds world considers them special ... but you have to think ... To start, it's a land yacht. Then add, any olds block lacks aftermarket support, but the diesel wasn't well liked when it was new. The only ones actively looking for diesel blocks are people that want them for high powered gas conversions.

That said ... it is rare. You'll likely be the only one at any car show with that setup. And diesels can be fun, if you know diesels.

 

Welcome to the site. I agree with the above, rare but not desirable.

 

My uncle used to buy diesel Olds cars on the cheap in the late 90s and swap in gas engines. He said the hardest part of the swap was changing out the "diesel fuel only" on the gas gauge in the dash.

 

Keep the block for an SBO stroker build. Junk the rest.

 

Thanks for words of wisdom. My very first car was a 65 Cutlass with the trunk so rusted that a milk crate fell out while going down an old country road, loved that car. I just bought an 86 Olds 98 for my boy and he is enjoying the motor city classics. I'm looking for a daily driver to use for work and back driving the back roads of North Carolina. Something big and comfy. Any suggestions for good years or models? I don't necessarily want a diesel just came across one close by on craigslist.

 

the 84 and 85 are the ones to have as far as the diesels go.they have all the updated parts etc.the only things we ever did to ours is rebuild the pumps and replace head gaskets when they blow.buddy's dad had a bunch of em that will be going up for sale soon.has an 83 88 2 dr real nice chanpagne with maroon landau top,also has a super nice 84 buick le sabre limited 2dr. tan with brown landau top.also has an 82 buick electra.plus a couple 4 drs.

 

those cars make a great home for a 455

 

IMO the Olds Diesel was nothing more than a half hearted attempt to produce an engine that was more fuel efficient at the time. They're noisy and don't have a lot of power, plus they don't burn all that clean. The head bolts are also very weak and prone to failure, causing head gasket leaks. The fuel delivery system was also noted as being a weak spot.

An 84 Regency Brougham is a lovely car, I had an 83 with the 307. If your project is going to take a lot of work? You have options. If you can get it super cheap, do like Dave suggested - yank the Diesel, and swap in a 350 or 455. Actually the diesel block is cast a bit stronger than a standard 350, so you could bore it out really easy, and put on the heads of choice. If you do swap in an Olds 350 or 455? they will bolt right up to the 200-4R in the car and provide a lot more fun to the driving experience. Of course the other option is to walk away from this car, as it may become a money pit. Ha ha, either way it's going to be a money pit.

I have to say I have absolutely no idea how much work it may be to swap out the engine, but you will likely also have to flush or replace the fuel tank/sending unit and fuel lines. As far as the escutcheon plate that says Diesel Fuel Only? That's an easy fix. Those dashes are super easy to open up.

 

Aside from trying to get better fuel economy in a land yacht, Wern't they also trying for high torque and avoiding emission controls? I think it would be pretty cool, but they were not known for being trouble free. There are some people that have most likely figured out how to fix the bugs. But at a cost.

 

I think the best thing GM did for better fuel economy with those 80's land yachts was to install 200-4R transmissions, and add decent highway gears. IMO while the 307 was reliable (at least mine was), it was no tire shredding monster. Low hp, low torque, but really decent fuel economy.

I haven't seen very many 70's/80's diesels that had good emission controls. I think one of the incentives for diesels back then was the relatively low cost of fuel compared to the cost of gasoline.

 

that and out here in iowa a lot of farmers bought em and ran fuel from their barrel they used for their farm tractors"no road tax".so even cheaper

 

Here in California they are smog exempt. So buy one and put whatever you want in them.

 

swapping in a gas engine is as easy as an engine swap gets even using a 455.only thing i did with fuel system besides blowing fuel back to the tank was dropping the tank and cleaning the sock(they get clogged ) on the pickup and then cutting the return line off just under the sending unit to use as a vent.running a hose from return line under the hood to the air cleaner .if not you have to use a vented cap. if gm had only started with the DX block and the 200r4 they would have had a considerably better reputation

 

Like many GM ideas the Olds diesel had just about had all its major gremlins worked out just before the plug was pulled.
The engines produced in the last few years were reliable enough, although woefully underpowered, however they did give good mileage for leisurely driving.
Swapping one out for a gas engine has always been a popular modification, as has been said diesels are rare but not particularly desirable, but as there are less and less of these cars left possibly they might take on added value simply because of their rarity.

Roger.

 

Buddy of mine had a Cutlass Salon 2dr with bucket seats,5spd manual and a 260v-8 diesel.Great mileage,but the bumper sticker said"0-60in 13 mins"

 

sure that wasn't a v6.they made 2 different v6 diesels one for the front wheel drive cars had aluminum heads and the narrow bolt pattern for the trans.the rear wheel drive had cast heads and the standard olds bolt pattern for trans.i have a front wheel drive v6 that i replaced the heads with cast.it idles as smooth as my old 330.

 

The first couple of years of the diesel they made a 260 V-8 diesel for the cutlass,regal,etc.If they blew up under wty,they replaced it with the 350 V-8.I worked at an Olds dealer then.