'98 V70 D5252T engine vibrations
 

Hi Folks,

My '98 V70 TDi auto is a great car, esp when cruising on motorways etc. But, and it's a BIG but, when you're stopped in traffic, in gear with your foot on the brake the engine vibrations you can feel in the cabin are genuinely very disturbing, and bizarrely are causing my legs and back to ache! They literally shake the car.

I'd posted about this before up the V70 forum, and got some great feedback. As a result, I found the gearbox was resting on the small rubber 'bumpstop' on top of the chassis. So I replaced both front & rear engine mounts (the big round hydraulic doughnuts with volvo parts), which lifted the gearbox up off the mount by 1.5cm or so. I think it may have reduced the vibration a bit, but that could just be wishful thinking as it was murderous job! Is it possible I somehow got the front rear mounts mixed up? They look identical, but have diff volvo part numbers.

I fitted a new top steady bush (engine end of the arm), but this made little difference. Although, i did notice the bush seems forced towards the bulkhead rather than sitting in a 'relaxed' position. Is this a clue that the engine isn't sitting right?

Crank pulley damper and the pulley-end engine mount looks fine and hasn't bottomed out, and the under-strap looks fine.

While visiting family in the Midlands I got CP motors to fit a full timing & pump belt kit, with water pump and all the bits (inc a crank seal). They thought the car was fine, but I'm really struggling with the idea an 'executive' car like this was this coarse when new....or was it??!
The car starts & runs fine, but strangely the mpg dropped dramatically after the belt swap?? .

Any ideas what could be wrong to cause this intense vibration at idle? Once the revs rise beyond 1000-1200 it all smooths out, and at speed it's a wonderful car.

Sort of at the end of my tether with this one, I love driving the car but this vibration is literally starting to hurt.

Any ideas??

cheers,

Rich

PS; could a ropey injector cause somthing like this or would that throw up a fault code, but then I suppose you's feel it all through the revs.

Only when in gear with foot on brake....

Does it still do it if your in neutral or park and put your foot hard on the brake?

Hi,

The vibration is def at its worst, in gear with your foot on the brake. It lessens slightly when you drop into neutral or park or raise the revs by 100 rpm or so.

I've been looking at the Audi forums to see if anyone mentions this over there, but nothing as yet.

Any pointers would be gratefully received!


Cheers,

Rich

Assuming your gearbox is ok, engine mounts ok, subframe all bolted up ok, I'd basically say that we want to get your engine running smoother then, and a drop in mpg also inditactes something is not as it should be. Parts can clog up but still work, hence no warning light or error code. I personally would do this:

Replace fuel and air filter
Clean MAF sensor and area around it. (Maf sensor is on top of the air filter box inside the start or the pipe)
Check turbo air pipes are not full of oil (turbo leaking oil/ turbo core worn out but you should notice strange noises from the turbo if this was the case and a loss in engine oil level)

Check breather pipes and little pipes to pressure sensors etc are not clogged
Replace CO2 sensor
Use a fuel system/injector additive in the fuel

If that cures it, should help your engine run smoother and give it more tork to prevent the vibration / engine struggle

How about the top of the front struts, is it all good there?

Hi Mickeyboy,

Ta for the info.

In a funny way, you've sort of hit the nail on the head. The engine seems harsh and a bit rough, now I don't have any experience of these engines so I can't honestly say mine is any different from other TDIs. But it certainly is harsher than other diesels of simillar age, maybe this roughness is inherant in the 5 cyl design.
Were they known for being smooth engines when new?

So I think I need to compare it to another V70 as soon as poss, at least I'll have a comparison then.

I'll check out those things you suggest...

Assuming your gearbox is ok - slightly clunky, as you'd expect it to be a 190K. Fresh ATF 2000 miles back.

engine mounts ok,- They 'appear' ok, how would you confirm? Crank pulley-end mount moves, but hasn't bottomed out and the rubber looks in good nick

subframe all bolted up ok, - are these the large round sandwich type mounts at each 'corner'? If so, not fantastic, some cracking on surface

I'd basically say that we want to get your engine running smoother then, and a drop in mpg also inditactes something is not as it should be. - engine felt the same before the cam belt change

Parts can clog up but still work, hence no warning light or error code. I personally would do this:

Replace fuel and air filter - replaced approx 2500 miles ago

Clean MAF sensor and area around it. (Maf sensor is on top of the air filter box inside the start or the pipe) - woudl suggest I take it off and wash through with carb cleaner?

Check turbo air pipes are not full of oil (turbo leaking oil/ turbo core worn out but you should notice strange noises from the turbo if this was the case and a loss in engine oil level) - other than being 'wet', no oil in aire pipes. Turbo sounds ok, no oil loss

Check breather pipes and little pipes to pressure sensors etc are not clogged - ok, will check.


Replace CO2 sensor - do you mean the oxygen sensor on the exhaust?

Use a fuel system/injector additive in the fuel - have tried a few tanks of such stuff, wiht no difference. Maybe I should carry on?


Would worn injectors add to this 'rough' running?


Thanks again,

Rich

The maf sensor is a wire partially protected by plastic, its about 3cm long dangling down, I used electrical cleaner and a cotton bud to clean mine, believe it or not you can actually by a spray can of maf cleaner (although its likely to be the same stuff)... Its easyly reachable if you undo the filter box and look into the top part. There is a small pipe that connects from the airbox area to the turbo hose, just be careful not to break it off in the process...

Yeah sorry, O2 sensor in the exhaust...

Another point, did you replace the filters yourself, or did a garage do it, or did a garage say they did it? You'd be suprised sometimes they accendiently miss one or two...

If an injector is not spraying evenly or efficiently, it will effect performance. You can take them out and inspect each, clean them up if need be and or replace one. Never had a injector issue myself, last time I did a diesel rebuild I just cleaned them all up and had no issues... I would expext a clogged injector would get worse over time and effect performance further. Same with a valve, I'd expect it to be as bad throughout the revs.

Another thing I do occasionally is when engines warmed up, floor it up a hill in 2nd upto redline 2 or 3 times (obviously not going up the hill 2 or 3 times, just red line it 2 or 3 times while going up the hill). to clear the weeks soot out the exhaust.

I used to drive a R reg V70 when it was brand new for a company (although manual). It was smooth but not as smooth as say a audi 1.9 tdi... It is a slightly more chunky engine... With 5 and 6 pot engines, you wanna get them to purr nicely as best as poss.

Strongly recommend cleaning the maf sensor, it made a huge difference to mine.

Hi Mickeyboy,

Good point about the filters, but all ok. I replaced the air filter and the fuel filter was changed when it broke a few months back due to an air leak on the top of the filter housing.

I'm sort of thinking, that while the injector aren't spot on I'd think you'd feel a faulty injector throught the whoel rev range.

Will do an 'italian tune up', haven't done it for a while (well at least not on purpose!)

Was your V70 a diesel? It's hard to describe the vibration off this thing. I'd expect to know it's a diesel at idle, but not to really feel it to the point it's very uncomfortable to the point I really don't like sitting in traffic.
My 940 D24 diesel was fairly smooth at idle. Yeah, you knew it was a clattery diesel, but in the car you could happily sit all day in traffic (as I often did). Same goes for my previous mk1 Mondeos.

Thanks for the pointer, it's really appreciated.

Cheers,
Rich

Hi Mickeyboy,

When you talk of the strut top bearings, how would this be related to the vibration?

Cheers,

Rich

I just thought it may amplify the vibration if is worn on the top there of the struts if they are a little loose. Also if the flexable join on the exhaust down pipe, if its not so flexable for some reason could amplify the vibration along the car? Just a thought...

Yeah it was a brand spanking V70 tdi at the time when I was with that company....not my own unfortunatly.

At the moment now I own a 850TDI, its mostly the same except the interior....