Vibration increase, particularly at idle…any ideas?

[Moomoo]

Originally Posted by Laird Scooby

I never said they were any good Ellie!

As a truck engine, not much use but not so bad in cars.

I loved mine, like me, totally unsophisticated!

[jpliddy]

hi all
the D24 6 cylinder has served us well . not really fast but reliable workhorse
returning up to 40 mpg on motorway cruising never less than 30mpg around town the petrol 900s are great cars too i have only had volvo since 1984 , so you like them or you don't ,my personal opinion only,

[Moomoo]

Originally Posted by jpliddy

hi all
the D24 6 cylinder has served us well . not really fast but reliable workhorse
returning up to 40 mpg on motorway cruising never less than 30mpg around town the petrol 900s are great cars too i have only had volvo since 1984 , so you like them or you don't ,my personal opinion only,

There's one on fleabay in S-O-T, £1600ish! I'd be tempted if l had the space!

[jpliddy]

Hi yes ive seen it i can only afford to run 1 car so will stay with my 1995 D24 after 21 years and 256000 miles driven by me ,its been a good servant but has had its problems but nothing i can't fix or a professional can't fix im on 286000 miles so hopefully get to 300000 miles in a few years

[Moomoo]

Originally Posted by jpliddy

Hi yes ive seen it i can only afford to run 1 car so will stay with my 1995 D24 after 21 years and 256000 miles driven by me ,its been a good servant but has had its problems but nothing i can't fix or a professional can't fix im on 286000 miles so hopefully get to 300000 miles in a few years

My hat is raised Sir !🎩

[Laney760]

Originally Posted by Laird Scooby

I never said they were any good Ellie!

As a truck engine, not much use but not so bad in cars.

Yes, the engine was much better when it was in my 940TD (now in a museum) and in my 760TD (now owned by Rod)!

[AllHailKingVolvo]

Thanks all!!

I agree about the D24 being like a little truck engine. I love mine. 292,000 miles and always ready to go! I bought it from a fellow forum member (Oman5) and have put a lot of work into it over the last year or so. I was hospitalised for two months just after I bought it, and it was a great project to focus on whilst I was recuperating, and remains something I associate entirely with positivity, healing and fun. It’s my daily driver and, as much as I love my redblocks, I think the derv is probably my favourite, for all manner of reasons.

The vibration is intermittent, weirdly. Sometimes it will be smooth as silk, other times the vibration returns.

My starter motor is on the way out (I have a replacement ready to fit, but it’s a fiddly job so have been putting it off!) so I’m wondering if that’s a contributory factor, perhaps it isn’t fully disengaging from the flywheel or similar at times. The start of the vibration coincided with the start of the starter issues. Usually at the first turn of the key it will spin up but not engage, then the second time it will engage and start the car.

The engine is running very well on the 5w40 so I’ll stick with that for now as I’m sure that isn’t the root cause of the vibration.

[Laird Scooby]

Originally Posted by AllHailKingVolvo

The vibration is intermittent, weirdly. Sometimes it will be smooth as silk, other times the vibration returns.

My starter motor is on the way out (I have a replacement ready to fit, but it’s a fiddly job so have been putting it off!) so I’m wondering if that’s a contributory factor, perhaps it isn’t fully disengaging from the flywheel or similar at times. The start of the vibration coincided with the start of the starter issues. Usually at the first turn of the key it will spin up but not engage, then the second time it will engage and start the car.

The engine is running very well on the 5w40 so I’ll stick with that for now as I’m sure that isn’t the root cause of the vibration.

You've answered your own question there Phil - the starter is only engaged when it's turning the engine.

I'm still convinced it's the oil, you've gone to full synthetic 5W40 from 10W40 semi synthetic. The molecules in synthetic oil are smaller than those of mineral/semisynthetic so that's a good clue. Try adding (as already suggested) ~0.5L Carlube ATF-U or NAPA MVA synthetic ATF to the engine to see if that gives any improvement - it won't be instant but with a couple of hundred miles use you should notice it's smoother. I still think you'll have to revert to 10W40 semi as the main engine oil though but i'd add 0.5L synth ATF at each oil change as well. I do this with both of mine (only one has hydraulic tappets though) and both have improved emissions year on year as a result. Both are also as smooth as they should be as well.

[Forrest]

Not owning a diesel I don't pay a lot of attention to details about these engines. However, I'm pretty sure I've seen on other forums about them running very well on 5W-40. I guess this assumes there aren't any faults with the engine that a slightly heavier oil would help to mask.

[Laird Scooby]

Originally Posted by Forrest

Not owning a diesel I don't pay a lot of attention to details about these engines. However, I'm pretty sure I've seen on other forums about them running very well on 5W-40. I guess this assumes there aren't any faults with the engine that a slightly heavier oil would help to mask.

On my other beast (which still isn't diseasel) that does have hydraulic tappets, many owners have tried fully synth 10W40 and wondered why it suddenly started idling so badly. The cure has always been to revert to semi-synth 10W40 and i'd guess this would be similar on a 300k miles D24 engine. Also bear in mind many people don't acutally realise when it's idling badly on thinner oil because they don't have mechanical sympathy/empathy but because they've been "told fully synth is better" have thought everything is ok. It might be better for a modern engine designed to run on it but not for something designed in the 70s when even semi-synth was exotic!