V50 1.8 petrol idle issues
 

I know this has been reported elsewhere but I can't find a good solution description.

My 2006 V50 1.8 has strange idle characteristics. When you pull up and put the clutch in the idle drops to about 300-500 RPM and then goes up to about 1100 then back to 900 (which is presumably the correct level). It seems to be getting a bit worse and drops very low sometimes (hasn't stalled yet). It seems a bit better when the engine has warmed up properly.

Is this likely to be throttle body / air valve cleaning job? or vacuum hose somewhere?

I have the same problem with my 1.8 engine. Looked everywhere for a solution but can't find one. I think that it's a common fault with the 1.8.

Is it because you put the clutch in, or are you just doing that anyway?

What happens if you rev it to 3000 rpm (while stationary), hold it for a few seconds, then suddenly release?

I don't get this at all on the 2.0 petrol engine and from what I gather it's meant to be a very similar engine.

The revs will dip when putting the clutch in during normal driving. For example , when stopping at a junction. I've cleaned the throttle body and checked the vacuum pipes but the revs still fluctuate.

I realise that this is an old post but I have had the same problem and worse with my V50 1.8 petrol. I had not long had it when it started doing this and it was difficult to start also when it had been left for a couple of hours.

Took it back to the dealer who took it to their garage saying they suspected throttle body. This they said was cleaned but it did nothing and after the dealer was very reluctant to do anything saying it could be very expensive and didn't want to keep swapping parts over that may not fix it. Keeping things civil lets say many discussions followed.

I came on here and found others having the same issues and having problems resolving it with poor results from Volvo dealers. Anyway after consulting with the dealer I took the car to a local indie for a full service (not yet ready but not to far off needing one). He said he knew what it was, wiring contacts will be corroded. He cleaned everything, didn't work. He said could be throttle body, accelerator pedal box, air sensor, inlet manifold flapper valves but cant say anything for definite as the car shows no faults and is up to date on all software. By now I was well miffed and hated all Volvos. He could only advise changing one part at a time and see what happens. This was echoing the dealers statement so it told me dealer had seen this all before.

Back to the dealer he would not shift and was not prepared to do anything. I put a very poor feedback on his site and took advice. He agreed to look at it again, told me to take it to the local main Volvo dealer where he got it from for them to do a health check. I took it to them and they found no faults and said the car was showing up to date on its software but if I wanted too they would do a re program for lots of money but didn't advise it. They could only say the same as the indie and start swopping parts. THey said they would give no guarantees that any part would fix it nor would they put the old parts back on if it didn't. I decided Volvo's really are crap and the dealerships even worse.

As I was leaving the technician who had worked on the car came over for a chat. He said I can only give you the official Volvo blurb but my experience of this same engine in Fords and Mazda is it will be the air sensor in the manifold after the throttle body. He then proceeded to show me where it was and said clean that first, if that doesn't work replace it, always sorts out a Focus with the same problems.

Went back to the supplier who arranged for it to go to another garage they use for warrantee work, who I had dealt with a lot, to get the car checked again. He said its the throttle body definitely, it will be very expensive it may need the Volvo software to set it up and I don't have that but it would work and I would have to take it to Volvo after. He suggested I investigated if it would need setting up after. By now I hate all Volvos even more and the car is getting worse and cutting out whilst driving.

I go back to the supplier after all he's paying the bill. He says he's going to talk to the garage. Mean time I get talking to a mate at a classic car meet, he says try some Winns EGR cleaner its brilliant for this type of thing and it worked for him. I got some from Halfords £10.00. That night I spoke to a mate of mine who designed and developed car engine management systems for BMW and Rover, and also develops engine tuning. He says bring it over to me I've got all the latest Volvo software let me check it out.

Next day I go over to his house he plugs it in and says that's ok, that's ok mmmm showing no faults but showing its not firing correctly at 3000rpm and not picking up well. Lets try your snake oil from Winns wont do any harm.

Has a look at the throttle body and said this hasn't been cleaned or touched since it left the factory. He didn't remove it but cleaned out as much crud as he could with a rag and following the instructions on the can applied the Winns. It amazed us both, the car was still plugged in and the effect was noticeable immediately, running smoother before the procedure was completed. Since it was done I have had no problems for 4 months, the snake oil worked. We suspect it was the air sensor that had 80,000 miles of crud on it making it not work correctly so not sending the correct messages but at the same time not showing as faulty. I have got another can with the intention of giving it another dose at sometime.

Online feed back gives this product rave revues with many using it every year when servicing.

I can only advise try it its easy to use, it works, and now I like my Volvo a lot.

If it doesn't remove and do a full clean of the sensor or replace it, I am told its the cheapest part, but if this doesn't work you could be in to the expensive business of having to change one part at a time till its resolved.

Thanks mate. Nice post.

I'm experiencing the same issue. Annoying to say the least. My 2005 1.8i only has 40k miles on her. Possibly coked up.

I'll get some snake oil and give the throttle body a good seeing to.

Many thanks for posting up your experience and advice.

Ken.

Same problem
 

I have fitted a new sensor , had the inlet manifold off and found a burst breather hose , which I replaced, I washed out the throttle body and cleaned the EGR, put it all back together and it is still doing the same thing unless you put your foot on the clutch and then it behaves. Have removed the clutch switch and the car behaves , just no cruise control as you would expect.

Clean the TMAP sensor. That will make a big difference. Its a fiddly job on the V50 1.8 but worth it. The sensor is down the front of the engine behind the inlet manifold.

hi everyone! I am new on this forum but I am experiencing the same problems with my Volvo S40 (2006) with the 1.8L petrol Duratec engine.

This problem only occurs when idling and the car is moving. Normally this problem is more pronounced when it is in neutral with the clutch in up position. However, it does occur sometimes too when I have the clutch pedal down. The RPM will drop to around 300 rpm and then bounce up again to somewhere around 1200 rpm.

I made a small video indicating the problem. Tachometer is in KPH, so I was doing around 40mph when I pressed the clutch pedal.

https://youtu.be/u1uiP2RrECQ

I have found numerous potetial fixes for this problem and I just wanted to make sure I'll do this in the right order of most likely things that it will fix:

1: clean throttle body
2: clean mass airflow sensor
3. clean TMAP sensor

I understand that this engine has an electronic throttle body. What is the best way to clean this? I've seen some videos where they put the key to position II and press the accelerator to open the valve. Or is it easier to disconnect the battery, wait 15 minutes, remove air intake hose, unplug and unbolt the throttle body and after that clean it when it is off the car? And can I then open the butterfly valve when the throttle body is off the car (overriding the electric motor)

any help is appreciated