1.8L petrol failed emissions badly

[thecuist]

Hi all
Looking for some technical input as to possible reason for my V50 failing its emissions terribly.
Information to hopefully help:
Volvo V50 2005 reg 1.8L petrol (NOT bi-fuel)

Low Idle:
CO = 3.91%
HC = 1,114ppm

High Idle:
Lambda = 0.86

The testing station said they had to abort the rest of the test because their equipment was getting blocked up because the readings were so high.

The car has done 150K miles but only 2 owners from new and the last owner appears to have kept up with servicing very well and car appears to have been well looked after.

Fuel economy appears to be about right, she is running at around 7L/100km which equates to 40mpg which seems about right considering the mileage and the fact that she is running very rich. There are no warning lights lit on the dash and I know the MIL light is functioning because it lit up briefly after a very flat battery but then went out after a good run.

So far I have checked as best I can all vacuum hoses and cant see anything out of place. Engine seems to be running smoothly with no misfire and no lack of power. I then checked the front oxygen sensor using a digital multimeter with engine fully warmed up. There seems to be correct resistance on the two white wires for the heating element, but the voltage reading on the sensor wires is cycling from 0 - 0.350 mv approx once a second which If I understand correctly indicates running lean. This would then send a signal to ecu to pump in more fuel which would explain the running rich I think. But, surely if the engine is running rich as shown by the emissions test, then that lambda sensor should be reading rich i.e closer to 1V. Therefore would i be right in thinking that the front lambda sensor is reading faulty i.e lean when it should be reading rich and therefore is faulty??
Sorry for the length of this post but im getting nothing but iffs buts and maybe, from local garages who are saying things like hmmm could be knackered engine, could be knackered CAT, could be knackered Lambda, and they all glaze over when I start talking about Lambda voltages. lol.

[mattievrs]

Could be anything really mate, but I'd start with changing the lambda sensors first then see what it reads then. Could be burning oil, could be a failed cat convertor, the list is endless really. As I said though, change the lambda then rag it hard to get the cat really hot and put it through an emissions test and see.

[pgm]

I would get it checked with Vida/dice and someone who knows what they are doing. Might save you a lot of time and trouble in the long run.

Paul

[kebab10]

Why not start with the basics? How old are the plugs? Are they genuine Volvo ones correctly gapped? Fuel consumption maybe okay even with less than ideal plugs, BUT Volvo plugs are best in these cars. Dont forget the air filter either. Basics, then faff about with these lambda voltages.

Hope my twopenneth helps.

[Daim]

Get on the road and give it some welly! High revs low speed etc. - looks like a catalytic convert or not working properly due to age... Then head to get it checked by a Workshop again. How was the emissionstest done? Via OBD or sond up exhaust?

[T5R92011]

I'd go for new lamba sensors and Cat.... though i would suggest avoiding any cheap ebay cat as they tend to do the bare minimum in terms of pollution reduction.

[thecuist]

Firstly thanks to everyone for their comments, heres an update on the situation. Took it to a diagnostics specialist and so far we have changed the plugs for new iridium tipped longlife £15 a pop. OUCH.
He did a smoke test for air leaks and found none.
We verified that the o2 sensors are reading correctly (very rich)
Changed oil and filter because he suggested that with that much unburnt fuel the oil could be contaminated and be throwing the readings out, HC readings have dropped from near 1200ppm to about 600ppm which is still 400ppm above minimum requirement for emissions.
He checked injectors for leaks and says they are all ok.
Only fault code coming up is o2 sensor reading out of range rich, and the sine wave on oscilloscope shows the same.
We are pretty sure its not a CAT issue because the upstream o2 sensor is showing rich and is trying to lean back the fuel to compensate but cant lean it enough so its switching to open loop operation, which as I understand it means that it goes to a default base ECU map and stops using the o2 sensor signals to control mixture.
So now I'm thinking possible worn injectors/high fuel pressure, or possible MAP sensor issues.
I know the injectors aren't leaking but is it possible to have worn injectors which dont leak? and if fuel pressure was too high could that cause too much fuel to be delivered.
Any thoughts? Is there a way to test for worn injectors without buying replacements and testing emissions afterwards, and what should the fuel pressure be at the rail?

[KBB]

Note you state the O2 sensor is stuck rich, create a lean condition by removing the brake servo hose and see if the sensor reacts and if it dose the STFT will start going positive proving the sensor is good and the fault lies else ware.

Is the sensor proves good then locate the hose running from the EVAP canister to the manifold and clamp it off, if the trims start going positive then the EVAP control valve is likely stuck open so permanently drawing fumes from the tank.

[thecuist]

Thanks KBB
I think we have managed to successfully prove that the upstream o2 sensor is good. I initially thought it was stuck lean, but when the tech plugged into the OBD port we were able to see the trace from the sensor making a proper sine wave. And then if I recall correctly when we raised the RPM it settled near the top approaching 1V. I will definitely suggest to him that we do that evap cannister test you outline. I hadn't come across that as a possible reason for the running rich in all my internet searches. But it makes perfect sense. I wish I had all the diagnostic kit myself because its always difficult trying to suggest to a mechanic how to do his job, but he seems like a pretty reasonable chap so should be ok.

[jeffmasson]

Firstly thanks to everyone for their comments, heres an update on the situation. Took it to a diagnostics specialist and so far we have changed the plugs for new iridium tipped longlife £15 a pop. OUCH.
He did a smoke test for air leaks and found none.
We verified that the o2 sensors are reading correctly (very rich)
Changed oil and filter because he suggested that with that much unburnt fuel the oil could be contaminated and be throwing the readings out, HC readings have dropped from near 1200ppm to about 600ppm which is still 400ppm above minimum requirement for emissions.
He checked injectors for leaks and says they are all ok.
Only fault code coming up is o2 sensor reading out of range rich, and the sine wave on oscilloscope shows the same.
We are pretty sure its not a CAT issue because the upstream o2 sensor is showing rich and is trying to lean back the fuel to compensate but cant lean it enough so its switching to open loop operation, which as I understand it means that it goes to a default base ECU map and stops using the o2 sensor signals to control mixture.
So now I'm thinking possible worn injectors/high fuel pressure, or possible MAP sensor issues.
I know the injectors aren't leaking but is it possible to have worn injectors which dont leak? and if fuel pressure was too high could that cause too much fuel to be delivered.
Any thoughts? Is there a way to test for worn injectors without buying replacements and testing emissions afterwards, and what should the fuel pressure be at the rail?

All ready said but I am going to repeat as its well worth a try and get it plug into Vida as it my have Volvo only faults that's will not show up with a obd2 or put up a mil. £75 on eBay if you know your computers or find a member near by. Or take it to a Volvo specialist as they will have the kit.

Well worth the £75 as the software has a full parts list and workshop manual as well. Just a pita to get working so not for a novice computer user.

Good luck

[thecuist]

It has just occurred to me that when I fill up the car there is no hiss from the filler cap. That would suggest that the system is not sealing properly and I guess that as the purge valve is connected to the fuel tank, if the purge valve is stuck open there would be no pressure inside the tank and lots of fumes going into the engine. Hmm I wonder if this could be the answer to the problem. I have checked the seal on the filler cap and it seems to be in good condition and the cap closes properly as far as I can tell. Only weird thing is that there is no fault code relating to this valve. Most of the problems with this system seem to trigger a fault code.

[KBB]

It would be very useful if you cask the tech what to look at freeze frame data in particular what the RPM and load is at when the DTC is set. A DTC for the EVAP control valve will only set if the is an electrical open, short to ground or short to power. If it is mechanically stuck open the will be no DTC un less your EVAP system has the in tank pressure testing sub system and this is year and market specific. No need for VIDA to diagnose engine running faults a good quality scanner with bidirectional control will provide all the info required for a good tech to find the fault.

The is a huge misconception that fault codes point right to the fault (this is where the parts changing monkey's come unstuck), more often the codes them selves are symptoms' and not the cause.

[Whyman]

My OH Honda CRV failed on emissions about 4 years ago.

A colleague got me some Forte injector cleaner which I ran through as per the instructions. Car passed with flying colours and has done every year since then. Great stuff but I think it is only available through the motor trade.

[thecuist]

So having checked pretty much everything my tec guy has come back to me and said that the fuel pressure at the rail is 4.2bar which according to his data is too high. However he is unsure of exactly what it should be at idle, and also exactly how it is regulated. He spoke to a ford dealer and they weren't much help either. I have spoken to a volvo dealer and they are meant to be getting back to me. In the meantime is there anyone here who can give me definitive answers to the following questions.

1) what is the fuel pressure meant to be at idle on a Volvo V50 05reg. 1.8L petrol (NOT Bi-Fuel)

2) How is the fuel pressure controlled, I dont think it has the same setup as the T5 or the 2.4i which has a fuel pressure sensor that commonly failed.

It only has a single pipe to the fuel rail so no return, and no FPR on the rail. I'm guessing there is some kind of regulator or bypass in the fuel pump assembly in the tank

Any help would be much appreciated, you cannot believe how hard it is to find techs here on the west coast of Ireland.

[MacV50]

So having checked pretty much everything my tec guy has come back to me and said that the fuel pressure at the rail is 4.2bar which according to his data is too high. However he is unsure of exactly what it should be at idle, and also exactly how it is regulated. He spoke to a ford dealer and they weren't much help either. I have spoken to a volvo dealer and they are meant to be getting back to me. In the meantime is there anyone here who can give me definitive answers to the following questions.

1) what is the fuel pressure meant to be at idle on a Volvo V50 05reg. 1.8L petrol (NOT Bi-Fuel)

2) How is the fuel pressure controlled, I dont think it has the same setup as the T5 or the 2.4i which has a fuel pressure sensor that commonly failed.

It only has a single pipe to the fuel rail so no return, and no FPR on the rail. I'm guessing there is some kind of regulator or bypass in the fuel pump assembly in the tank

Any help would be much appreciated, you cannot believe how hard it is to find techs here on the west coast of Ireland.

No idea what the pressure should be but if there's no return pipe, there will be a sensor that regulates the fuel pump. Perhaps the sensor has gone bad but not so much as to cause the engine management light to come on.

[thecuist]

So thought I'd give an update on the V50 saga.
Basically having checked everything including replacing a MAP sensor which seemed to be reading a bit wonky the car was still chucking out HCs around the 800ppm mark. My tech guy said the only thing left that he could think of was oil control rings. We did a leakdown test and it came back perfect at only 7percent drop, but having scoured the net I came across an old timer test where you use engine braking down a steep hill and then accelerate at the bottom and look for blue smoke. Sure enough each time I did it there was a telltale cloud of blue, apparently this is a pretty definitive sign that the oil rings are gone. A phone call to FRF in Swansea later and I am informed that Volvo do not supply any bottom end internals for this car, you have to buy a whole new short end which is coming in at 3K this is not really an option as its more than the car is worth. More internet searches and it seems that aftermarket rings are thin on the ground too, a couple of Polish suppliers list them but I have no idea what kind of quality they would be or whether they would even fit.
Does anyone know of a reputable supplier who might have a set of rings for a Volvo V50 1.8L petrol. Or is it worth trying something old school like a Kerosene flush, as from what I'm reading on the Ford forums the oil control rings tend to get coked up rather than wear out, so if yu can clean off the crud sometimes the spring mechanism frees itself.
Ive also looked into getting a replacement engine but they are thin on the ground too, and pretty dam expensive.
Thanks in advance for any input.
Peter

[KBB]

I would not be keen to pursue that avenue until I had a good hard look at live data and look at what the short and long term fuel trims are doing at idle and part load whilst in closed loop.

[thecuist]

I would also rather not start spending 100s of pounds on engine rebuilds unless I was completely certain, but the tech guy I have been dealing with is the only one I can find reasonably locally who actually seems to understand the difference between closed loop and open loop. lol. I kid you not I took the car to a local garage who everyone uses and he didn't even have an exhaust gas analyser. 3 other local garages just wanted to change the CAT first and then go from there.
Anyways, to get back to your original suggestion the tech who has been looking at the car said to me that the o2 sensor was picking up the rich mixture and the ecu was leaning the fuel trim back as far as it could, but as the car was still running too rich the ecu was switching out of closed loop and back into open loop which as I understand it is a default map which is still too rich to pass emissions at idle.
I have to say that I am not 100percent confident that it is an oil ring or valve stem oil seal issue, but given the fact that the car is definitely giving out a noticeable amount of blue smoke at certain times and the mechanic does seem to know more or less what he's talking about (albeit in a slightly haphazard fashion) and the fact that the car does have a Duratec HE engine which has done 150K miles and there seems to be lots of anecdotal evidence on the net that these engines are prone to dodgy valve stem seals and oil control rings, I am reluctantly thinking that I may have to take the mechanics word for it.
I was looking at possibly buying one of these: https://www.obdsoftware.net/scantools/obdlinkmx. Would this enable me to gather the data you are looking for via their laptop based OBD2 software program. Or could you suggest something else. I spent a long time scouring the net for decent OBD2 equipment but there seems to be an awful lot of stuff that claims to be the best but probably isnt. I mean we need more than just fault codes, it has to have real time data streaming and while i dont think this has bi-directional capabilities it seems to be pretty comprehensive. The next step up in price looks to be heading towards £700+ which is more than I want to pay at the moment, given that I could well buy it and then still have to spend another 600 on getting oil control rings and valve seals done.
Thoughts?
Thanks
Peter

[MacV50]

From what you've described regarding blue smoke, it sounds like you have a ring problem as my understanding is as follows

worn stem seals smoke on the over-run
worn rings smoke under power

Could you also be getting oil forced past the rings due to crankcase pressure being too high? Something as simple as a blocked breather perhaps?

This engine is used widely in Focus and Mondeos, perhaps you could find one by going down that route?

[thecuist]

There are definitely issues with the valve stem oil seals. Cloud of blue smoke at startup after sitting overnight, and blue smoke on the overun after going down a hill using engine braking. I have managed to source a new set of rings and a new set of valve stem seals. My plan is to attempt to change the valve seals first without removing the head. Then test emissions again. If the problem remains I'll move onto the oil control rings. That way I can hopefully avoid having to strip down the engine if the valve seals do the job. I'll keep this thread updated with my progress for the benefit of others who may run into similar issues.

[MacV50]

There are definitely issues with the valve stem oil seals. Cloud of blue smoke at startup after sitting overnight, and blue smoke on the overun after going down a hill using engine braking. I have managed to source a new set of rings and a new set of valve stem seals. My plan is to attempt to change the valve seals first without removing the head. Then test emissions again. If the problem remains I'll move onto the oil control rings. That way I can hopefully avoid having to strip down the engine if the valve seals do the job. I'll keep this thread updated with my progress for the benefit of others who may run into similar issues.

Ah, OK. From an earlier post, it sounded like you weren't getting it on the overrun, only when you applied power again.

Hopefully it is just the stem seals. Good luck!

[thecuist]

Managed to change the stem seals on the 2 outside cylinders today. Dont have the specialist tools to lock the timing chain tensioner so just marked up all the various moving parts and undid the 2 chain sprockets and lifted out the Cams. As its an interference engine made sure cylinders 1 and 4 were at TDC and that meant the Valves only dropped 1/2 inch, no need for rope tricks or compressed air to hold the valves shut. No spring compressor so just used a socket and a magnet to remove and catch the collets/keepers. Valve stem seals were pretty bad, I'd say the holes in the rubber seals which go around the valve stem were a good 1 mm bigger than the replacement new ones I bought. Putting the keepers back on was a bit of a mission using just a ring spanner to compress the valve springs but got there in the end.
So then it was a case of reassembling the camshafts and sprockets.(I kept the sprockets in position and the chain tight using a piece of wood between the 2 sprockets).
Had a good deal of trouble getting one of the sprockets back on due to the timing chain tensioner pulling the sprocket slightly of centre but with a bit of careful leverage I managed to persuade it back on.
Then I checked all my timing marks and rotated the engine to get cylinders 2 and 3 to TDC. Took off with the cams and sprockets again, and tomorrow I'll change the remaining 8 stem seals and see how it goes. Fun and games.

[MacV50]

How are you getting on with this?

Hope you get it fixed with seals only

[thecuist]

Hi Mac
Changed the seals and now I have no smoke on startup, but still smoking when I bring revs up above about 1500rpm. So Im gonna get my local garage to change the rings. Assuming the Cylinder bores are ok when he has the engine stripped. Leakdown test was very good at only 7 percent so fingers crossed it is the just oil control rings. Apparently they are prone to gumming up on the duratec HE engines.

[thecuist]

For the benefit of others who may come across this thread. Changing the rings solved this problem completely. The emissions came down well below the limits required to pass an MOT. So if you have a V50 1.8 petrol which is failing emissions, and changing the plugs doesnt solve the problem. Even with a leakdown test showing perfect compression on every cylinder, its probably the oil control rings causing the issue. I bought replacement rings for about £70 and a new head gasket, plus bolt set for about another £100. Then found a good mechanic who charged me £400 to fit them.

[b4mky]

.... JUST BRILLIANT, did the same on mine, now perfect, Thanks

[thecuist]

Thanks for the thanks. That Volvo is now long gone, but glad to see its still useful info for the forum. Once I get around to restoring my 850r. Im sure I'll be back on here frequently.

[alcashj94]

.... JUST BRILLIANT, did the same on mine, now perfect, Thanks

Looks like I have to change the rings on mine, already done the valve stem seals and changed the PCV valve but still drinking oil and smoking on occasions.
Any pointers on any 'awkward' stages to be aware of, access etc. and roughly how much time should I allow myself to get the job done?