Hi folks,

this is my first post to this forum. I hope that someone might be in a position to give me some advice, opinions or point me the right way if this has been covered before. Any help will be most gratefully received

Right, I've got a 2006 Volvo V70 D5 185 bhp (Euro IV emissions). Its got about 63, 000 miles on the clock. Car still gives exactly the same mpg as it always has. I've had it for 3 years, never had a problem and its only needed routine maintenance. during warranty period it was dealer serviced but now thats over I'd rather do it myself, especially since the services seem to involve very little in the way of actually mechanical maintenance.

I have very little experience with diesel engines but have had a series of high performance petrol engined motorcycles that I've maintained completely on my own, so I'm confident of at least having a bash! Moreover, I live in Dublin, Ireland where customer service can be quite poor and the cost of almost everything is 2 - 3 X higher than in the UK (where I originate from). So would prefer to solve this myself and avoid being burnt by a dealer.

Of late, the car seems to hunt on partial throttle openings when cruising or when the throttle is shut off when slowing down. Its as if the engine is bogging down and the car judders. If it was a motorcycle I's say blocked carbs/injectors, but its a diesel car. This behaviour is really pronounced at approx 1700 - 1800 rpm. The problem disappears at higher revs and is completely absent under strong acceleration. At first I thought I might have got a 'bad' tank of fuel and, for sure, running some diesel injector cleaner through the system, combined with draining the fuel filter trap, seemed to help a bit. However, its coming back and now getting worse.

I'd planned to do the next service myself anyway, but this seems to be an issue that is outside routine maintenance. Having covered many, many trouble free, silky smooth miles, I want the car to be in tip top condition and this rough running spoils it and isn't ideal.

Since I'm 'new' to diesels I'm not confident of tracking this fault down . The throttle loading dependence suggest to me that something is going on with the fueling, whether this be a faulty injector, dodgy glow plug or possible something with the air flow. I was going to do the service in the next few weeks, but want to prioritise this first as my funds aren't limitless.

However, maybe this a common fault and someone here can advise me on what to check. As I said, any help greatly appreciated. I work long hours so might not get the chance to respond quickly, so apologies if this happens.

cheers
Neil

 

Hi Neil,

I'd check/change the fuel filters, run some diesel purge through the injection system, new air cleaner too. I don't know if volvo needs valves adjusted regularly in their diesels, but if so, do it. I am only knowledgeable relative to MB diesels but any rough running is almost alwys related to fuel delivery or valves on my 200K plus diesel.
Does opening the fuel cap produce any sound? Jammed tank vent?

 

Hi there RM,

thanks for the feedback. I'll give what you say a go as I'll do the full service soon anyway and the flush etc can fit in with this. At this stage, I'm just keen to try a few things so that if I have to surrender and put it in the garage, I'll have tried quite a few things first. My gut feeling is that there is a fueling issue but, as I said, I'm new to diesels.

Anyway, cheers for this. If it magically fixes things I'll report back here

Neil