88 volvo 240 wagon rattling and smoking

volvo
smoke
240

#1

i have an 88 volvo 240 wagon with 89K miles on it… it’s been passed down through the family, is in great shape and is a joy to own. i have always have it serviced at the volvo dealership and recently had a bunch of work done to it including complete lube, oil and filter change, replaced the radiator overflow cap, replaced a leaking valve cover gasket, replaced the oil pan gasket, replaced the rear diff gasket and added oil, and replaced the sway bar links (it was an expensive visit).

to my dismay, on the way home, accelerating hard up a hill, something under the car started to rattle and black smoke started coming out of the back of the car. i took it back to the dealership and they replaced a leaking seal that they said was the problem, on the way home, same thing with the rattle and smoke happened on the same hill… maybe just stop driving on that hill, right? so i took it back and they changed the oil again (the oil levels were a bit high) and said they couldn’t find anything wrong… drove the car home and seemed not to have the problem (though i did take it easy on the hill).

so today, i take the car out for a drive (usually just drive it on the weekend), and accelerating hard up the same hill i get the same rattling and black smoke that continues until i let off the acceleration. by the time i get home (a couple blocks later), it’s like nothing ever happened.

so a couple questions:

  1. any ideas what’s going on?
  2. is it safe to drive as long as i don’t accelerate hard?
  3. never had this issue before all the work was done, kind of seems like i should take the car back to the dealership, but this would be the 4th time for the same issue…

apologies if this has been answered in another form… did some searching and didn’t think there was a match.

thanks, volvo88


#2

About the only thing that comes to my mind is that during this whole chain of events oil has leaked onto some engine or exhaust part, and when you drive the car a while, that part gets hot, and it starts to smoke. Since you are moving, the smoke appears to be going out the back, probably from under the car. That wouldn’t explain the rattle though. Maybe they knocked an exhaust hanger loose during the sway bar link replacement, and that is causing the rattle. In other words, maybe the rattling would be happening even if it wasn’t smoking. Any time theres a lot of repairs, there’s likely to be some unintended consequences. Goes with older cars. A visual inspection by a mechanic would tell you “Yes” or “No”.

Could be a serious engine problem too, since it occurs during a heavy load. Mechanics have tests they can do, to test for that problem. One thing they’d do first probably is inspect the tail pipe for signs of oily black greasy residue, which could indicate the engine is burning oil. Do you find you need to add oil between changes?


#3

thanks for the reply… i generally take the car in for an oil change every 6 months or so and the mechanics haven’t mentioned anything about it being low… and the times i can remember checking, the levels have been ok (so no, i haven’t had to add oil in the past). i’ll check for oily residue in the morning and report back.

agreed that fixing a couple things on an older car can have unintended consequences… that’s kind of what i figured happened, but the service guys have looked at the car twice and haven’t found anything wrong… fortunately, since i’ve been with them for so long they haven’t charged me for the last 2 visits and seem concerned about figuring out what’s going on. i was just hoping to be able to go back to them with some ideas on what the problem might be.

agreed, it’s possible the rattling and the smoke aren’t related, but the only times i’ve ever heard the rattling, it’s followed by blackish-grey smoke out the back. i kind of feel like the rattling is associated with the acceleration… seems like if i let off the accelerator, the rattling slows, but if i give it some more gas it starts rattling again. when it starts, if i stop accelerating for a couple of seconds, everything “resets” itself and runs fine again. i think the car may loose a bit of power when the rattling and smoke starts, but that may also be that it’s my instinct to take my foot off the pedal when smoke’s coming out the back/under the car. you might be on to something with the exhaust though, as once before the car needed the exhaust replaced because it had come loose…


#4

Rattles under hard pulling may be the result of a failed motor or transmission mount, or failed lower trailing arm bushings below the rear axle. Look first at the engine mount just below the oil filter on the passenger side of the engine. If the car seems to want to steer itself from the rear end as you drive down the road, the trailing arm bushings are shot.

I cannot explain the black smoke, however.

The best place to post Volvo 240 questions is in the Rear Wheel Drive (RWD) section of the Volvo Brickboard forum. That forum holds a gold mine of Volvo 240 knowledge.