Riviera Diesel Reliable?

Someone locally here has a 1981 (I think) Riviera with a 350 diesel for sale. Are these engines reliable? He is the original owner, but I'd prefer an unbiased opinion. Is there any other info I should know about this car? He's not asking much for the car but I'd like something I don't have to fix all the time. My father in law is a mechanic and says to stay away from front wheel drives as they are far less reliable than the old rear wheel drive GM's. Thanks.

That engine was a reworked olds gas engine. They perfomance was pretty good for a diesel with good fuel mileage. But....that performance was achieved with real high compression ratio (22 to 1 I think). They like to blow their head gaskets quiet often. The had a lot of fuel pump problems also. Can be hard starter in the winter, thats why they have glow plugs and two batteries. As far as the front drive goes in the Riv's I think the are reliable as I have not had any trouble. Front drive have improved a lot over the years.<P>Gene

If you go to 442.com and go to the FAQ they have alot of info on all the engines but you will eventually find the diesel.Somewhere there it mentions something was improved on and I think it was by 1981<P>It also states early lack of diesel knowledge by the automotive public.Poor fuel.I'm also wondering what RPMs these things shift at. 3200 0r 3600 is pretty high RPMs for something that develops 22-1 comp.Thats what our V.W. did though. However most work diesels red line at 2100.Could be the people that expected them to run like gas motors that had the problems.<P>The biggest thing with diesels is you cant get in them cold and drive the hell out of them or rev them fast to warm them up faster.<BR>I know guys that blew head gaskets on their Fords with the International 6.9 also.<P>Every once in awhile on of these GMs show up around here too. So some have gone the distance.

Diesel cars and trucks are smog exempt so if the engine craps out on you, you could put in a stroked 528 Buick and the fuzz wouldn't have to know.

The 1981 and after Olds diesel engine have a stronger block and a roller cam. These engines have a DX cast in the block while the older engines only have a D<BR>With some minor modifications and high maintenance it can live for a long time.<BR>The problem with blowing head gaskets can almost be eliminated by changing the head bolts to stronger bolts from a Caterpillar engine.<BR>- The death of this engine is dripping injectors or injectors with low opening pressure. Because of this the injectors must be checked at least once a year. The old type of injectors (before 1981) can be taken apart and cleaned but this is not possible with the “new” (1981 on) injectors, you have to buy new ones.<BR>-Change oil every 300 miles.<BR>-All the glow plugs must be in operating condition, even if you are able to start the engine it puts an extra strain on the engine with one or more glow plugs out. Be careful when you take the glow plugs out because the tip can break off and fall into the precamber. (then you have to take the head off............)<BR>-The full size cars with this engine used a mechanical glow control that is screwed into the water jacket on the engine block. The rest (Cutlass, Riviera etc.) used an electronic glow control that is located under the dash. <BR>The electronic unit is very expensive to buy new (if possible) and difficult to find in used, operating condition. Before you buy a car with this engine make sure the glow plugs are operating properly.<BR>-Make sure you have good battery cables and good batteries.<BR>-Check and tighten the starter bolts at least once a year and make sure the mounting bracket on the front of the starter is in place<BR>-Let the engine warm up before you put a load on it. <BR>-NEVER start this engine by spraying staring fluid/gas in the intake!!!! (can mean instant death)<P>Vegard<BR>Former Olds Diesel owner.<p>[ 10-30-2001: Message edited by: Vegard ]

BoatSlip,<BR>Are you kidding? RUN, don't walk away. Unless this is the cleanest, nicest car in the world (and SUPER cheap, to boot) don't even consider it. That engine is a pimple on the a**hole of GM's reputation for (GENERALLY) very good engines.<P>Now IF you're buying it CHEAP and plan to swap in a gas engine, that's a different story. Just don't expect it to EVER have any collector value--either in original, or converted, state!

Honestly, I have never owened one, and I can only attest to the bad reputation they had - as I belive that also Olds put a diesel in some of their cars too and also had problems. Rumors had it that after about 1 or 2 years, or when the original owners wanted to trade them in - the dealerships weren't taking them back in on trade because of the poor reliability and performance problems the diesels had, knowing they couldn't unload them as used cars. I agree with the previous gentleman (unless you know the owner and can trust his word as to lack of problems)....RUN, RUN, RUN away as fast as you can. I would also think that replacement parts would be rather hard to come by as well.

I owned two GM diesel cars, a 1978 Olds and a 1982 Pontiac Grand Prix. These were both beautiful cars but I found the diesels to be very high maintenance. It seemed there was always something in need of repair. For example, at about 70,000 miles the fuel injector pump would go out. When something needed replacement (like the alternator, starter, etc.), it was very expensive because most of the auxilary equipment was heavier duty than on gas engine models. Because of the high compression, the engine would eventially develop blow-by. I had to replaced the engines in both these cars. The 1982 was better than the 1978 but still left much room for improvement. In the winter, you really had to look after them if they were to start. If they really got cold (Minnesota), the only way you could get them started was to bring them inside a warm building. Well that is the bad news. The good news is that they were really fun on over the road driving at freeway speeds. Once that diesel got torqued up it would really fly. When passing another vehicle at 65 - 70 MPH with the throttle wide open, about the time you got alongside it felt like it was going to become airborne. If your looking for something with relatively low maintenance, I don't think you want a GM Diesel.

Thank you all for your replies! Not only will I run, but I'll hide too! Actually, the fella will take $500.00 Canuck bucks for his car, but after buying my 62,000 mile solid almost rust free California Centurion for $300.00 this summer, I think I'll just look for a cheap Impala. They're pretty much a dime a dozen around here.<P>Tomsriv:<P>Sounds like a good idea but I'm already building a roller 462cid BB Chev for my Pontiac. I ducked in time to miss the debris flying at me from all you Buick guys . The only car that ever beat my BB on the street when it was a regular cam/lifter/rocker arm engine was, wait a second, a Buick Grand National. Must have been the weight of the Caprice rag top holding me back!

My Mom's Diesel Eldorado started to smoke and run rough after about 15,000 miles of use even though it was impeccably maintained. By 30,000 miles things had gotten bad enough to warrant me changing out the engine to a 350 gas motor. Noise and smoke went away, power about doubled, and mileage went down, but she was able to use cheaper, non stinky, non staining unleaded fuel. Especially with computer controlled gas engines, diesels in passenger cars make no sense.

My uncle had an '81 Riv with a diesel. His lasted longer than most, about 70,000 miles. GM put in a new one for free! I would advise you to heed the advice metioned earlier and RUNNNNN!! Unless it's super clean and you're looking to convert to a gas engine.

Buy the Riviera and put a 6.5 turbo diesel engine in it. <BR>The 6.5 are a bolt on to the gearbox and even the motor mounts might fit.<BR>The glow control system on the 6.5 is the same as on the Olds diesel in the full size cars.<BR>This is not an easy swap but it is doable.<BR>Imagine this car with 205 (?) diesel horses<P> <P>Vegard<BR>Former Olds diesel owner

Vegard,<BR>But why?<P>Perhaps in Norway you guys have had to resort to unconventional swaps, but around here there are SO MANY cars to choose from, why bother with swaps??<P>As an earlier writer said...."RUN"!

I have a 81 Riviera with 45k org miles on it GM put a new crate engine in the car back in like 1983.

There have been 3 updates that I know of I will try to brake it down.

Most of the Improvements were on the heads they crack easy they start out with as low as 1lb of pressure bleeding back from the radiator. to missing and steaming all together.

On the glow plugs there are 2 styles that could have been installed a Hot start that was used in warmer areas and the Cold start these take a while longer to heat up but should start in winter unless you are in a -20 area and do not use the block heater.

As for FWD Please understand the Riviera FWD is almost like a RWD it is a transverse FWD transmission and they are like the Turbo 350's for RWD. Now these motors do rev higher than a normal diesel I feel this plays a part in the reliable area now if you are revving the crap out of it 4000 RPM or higher, you will have issues. and as far as I can tell 1981 was the only years Riviera has a 350 (Olds) Dsl in it after that they were putting in 4.1L gas and turbo 3.8's like the grand national.

If you are having cold weather start issues, I would check the Glow plugs first it could be the controller but if can check it quickly open the hood turn on key The wait light will turn on and when it turns off you'll a loud click as the solenoid is turning off. It was 19F here at my show and this car has not been started in 4 days and fired up smooth after 2 try's to start to glow plug heat cycles. and I did not have the block heater plugged in.

In a nut shell if you are looking at buying or driving one all of the time, Please do not drive it like a gas car drive it like a diesel and keep a eye on fluids and temps.

The one I have in the shop now is super clean from California and has a few issues people not knowing how to work on them and doing more damage than needed.

If you do have one and know diesels or Basically do a head swap on it get the heads checked , This includes any new ones for cracks even new parts can be bad. Around here it is $35 a head to have it cleaned and Magna fluxed for cracks. and because you have to use your old injectors please buy a new injector feed seal kit for every injector. (this is one of the problems I am fixing now) Dealer back them did not install new seals causing it now to leak a little around the injector bore. any questions feel free to ask. I am new to this site but I have worked GM Technical Assistance, or TAC for years.) hope this helped, I would invest into a Clymer manual for that car covering the diesel also just to make sure the injection pump timing is correct.

These cars are not for the Non diesel people parts are obtainable Heads are like $300 each from Auto zone not like the GM dealer you'll wait a long time to get some and could cost over $1000. I have had 4 of these and rule of thumb take care of it drive it right and it will last. Most of the problems were due to it being a 350 Olds gas engine converted to a dsl, This was done in the last 70' early 80's during the Gas crunch I work on them when I can. a head set of gaskets is about $50 bucks for Felpro. not bad and even with the hood on it is pretty easy to work on you can get to bolts with out turning your arms to hamburger.

Just on the Ford part the International 6.0 and 6.4 were like that also they would rev to over 3000 but people would not let them warm up I recommend let it idle at least 15 to 30 minutes, then it should reduce the problems.

If it was in the flint area It is more than likely the one in my shop now.

From what I saw down here in the DFW area of N TX, there could have been some issues with "quality assembly", but there were also issues with people buying them and considering them "a diesel" (as an over-the-road diesel) rather than a light-duty diesel (which nobody had seen at that time, but are in many vehicles in more recent times). End result, in the West TX oil fields, they'd last about 15K before they were broke and needed new blocks. I had TWO in different Chevy parts trucks and had no issues with them, the first one being "turned" at 70K miles (needed a pump replacement at 50K miles, which seemed to be normal). The other one was turned at 30K miles. The farmer who ended up with it "bought the farm" as it was in the shop many times.

First model year spec'd "diesel-rated" motor oil. Later years spec'd normal gasoline engine motor oil. With the first one ('79?), the THM400 would not downshift to low gear unless you were under 10mph, so every time I got onto the freeway in Dallas, it was manually shifted just before the governed rpm. NO problems, but that was what it took to merge with freeway traffic. We also used the diesel motor oil in that one, too. Exxon XD-3 initially and later Delo 400. I also learned to drive with the exhaust as "white" as possible, meaning "no smoke" and no excessive throttle for what you were doing. Try to drive it like a gas motor truck and you'd be disappointed. Drive it like it would run and you had to plan your moves in advance, rather than on the spur of the moment. This led to a more relaxed and professional demeanor.

The decreased operating expense side of things (diesel being less expensive than gasoline) would not "break even" until 100K miles. The diesel might get better fuel economy, but next year's gas motor would match the prior year's diesel's economy. Unlike later diesels, the "price of admission" was not repaid at trade-in time.

I never could tear one up, not that I tried, but the "against the governor" WOT manual upshifts took to the 4000+ rpm level regularly, many times daily, 5 days a week. BUT, the proverbial "little ole lady" in a rural town could break a crankshaft on her diesel Olds 88 on the way to the grocery store. Others wanted to run "over the road" style oil change intervals (50K+) as others just didn't understand how to effectively care and feed the GM diesel. We put Racor water separators on every one we sold as a part of the package.

Many of the improvements and enhancements had to do with piston crown design (even between carlines and model years!). Heads were upgraded and injectors were also upgraded a few times. I never did see evidence of "cold climate" glow plugs, but later ones did receive more effective glow plugs (being model year dependent, as evidenced by the GM parts catalog).

I liked the diesels for their bulletproof cold weather driveability. On the coldest days with a few inches of snow on the ground, I'd go out, turn on the ign switch to light the glow plugs, when the "WAIT" light went out, I'd hit the starter and it'd try to start . . . until the cold air cooled the glow plugs too much. Then it was another start cycle and it'd fire off and never falter (as a gas engine certainly might have). After things stabilized a bit, then I'd drive off slowly (especially with snow and ice on the pavement!).

One time, I went to a customer's body shop where it had snowed a good bit the night before. While I was there, a customer came in who'd hit a mail box and his wife (apparently) was mad about him damaging their car. When he left, he slid into a ditch across from the rural shop. I waited for them to get him back on the road before I tried to drive out. I started the diesel, put it into gear, and idled around the shop, through the gate, turned onto the road, and UP a hill to the main road. NO problems! I doubt I could have done that with a gas motor pickup, all things considered.

Obviously, my experiences were different from many other peoples' experiences with the GM diesel 350. It was a learning experience for us all . . . PLUS the fuel economy advantage (small that it was) kept us selling 454s. As we sold LOTS of Chevy pickups, that fact was significant to us AND worth the extra effort of driving a diesel.

The Ford/IH diesels had some of the same issues GM had with their diesels, including sheared-off starter bolts or blocks cracked in that area. Once the bolts got a little loose, the massive torque of the diesel starter (which needed the starter support brace attached between the starter housing and the engine block!!) would either break the bolts or break the cylinder block in that area. Of course, broken bolts were preferable to a cracked-out block!

Would I own one now? No way, just because there are many better engines out there now than there were back then. I certainly would not consider one for an engine swap, either . . . IF there were any left running. ONE thing is that the Olds 350 diesel engine weighed as much as a 454 Chevy engine did, which means heavier front springs and such if he engine is going into a chassis where it didn't come from originally. NOW, if you wanted to use a diesel block to build a killer gas engine, just put appropriate pistons in it, "re-dress" the short block with gas motor items, then put a distributor where the vacuum pump went (in the rear of the block). OR . . . if you wanted to get "daring", you could drill the heads for spark plugs and have a "direct-injection" gasoline motor (once you put pistons in it for the needed lower compression ratio) or modified a set of gas heads for the injection system. Several possibilities ... if you've got the excess time and money.

Enjoy!

NTX5467

Nice reply to a 14 year old post from Halloween of 2001. Might I say we are resurrecting the dead? A cousin of mine had one of these trucks and drove it nearly 200,000 miles without a lot of trouble other than replacing the Injection pump several times, other normal maintenance on any vehicle. Yep, Some went the distance. Some did not. Dandy Dave!

the diesel is one of the reasons i stopped turning wrenches at an olds dealer. first when the head gasket leaks, instead of smoking out the tailpipe, it bubbles into the coolant overflow tank. i've seen a couple the were towed in because the owner thought the transmission hand gone out, when real what happened was the crankshaft had broken in two(yes, they will still run if the timing chain still works. the other gm gas engine to diesel conversion was based on a pontiac block, and it worked very well