02 XC70 - Throttle body questions.

[jonesg]

OK, here is the long list. 10 items listed. Now it is possible one may cause another, but there is a lot of diagnostics to be done on top of all the other work. Some may be as simple as possibly cleaning an item and electrical connectors, but at least one means a part replacement, but then 3-4 may be needed:

Fault Codes - (These are Autel codes, but I believe these will also be what Vida would give) :

1) (643A) ECM-643A : Cam Position - exhaust: Signal too low

2) (2810) Permanent fault ECM-2810 : Front O2 (upstream) sensor (HO2S) bank 1 heating : Signal missing

3) (531D) Intermittent Fault ECM-531D : Malfunction indicator lamp (MIL) CEM: Signal missing

4) (280A) Permanent Fault ECM-280A : Front heated O2 (upstream) sensor (HO2S) bank 1 : Faulty signal

5) (3000) Intermittent Fault ECM-3000 : Inlet camshaft sensor : Faulty signal

6) (400C) - ECM-400C : Fuel tank system leakage : Minor leak

7) (6806) Intermittent Fault ECM-6806 : Turbocharger (TC) control system flow fault : Flow too low

(130A) ECM-130A: Air leakage intake

9) (990A) ECM-990A : Idle air trim : Faulty signal

10) (914F) ECM-914F : Throttle valve : Faulty signal

So any suggestions or advice if anyone can see a pattern or if any of the issues could be related your input is appreciated!!

I'm thinking the following actions:

1) Cam Position - Exhaust : The exhaust cam is the only one with a CVVT sensor on it - Remove and clean. Check resistance value, reinstall and see if issue resolves itself. It has the newer style plug connector on it so I may have a good used one worst case Need to compare part numbers

2) O2 Sensor - Upstream - Replace after checking no wire damage

3) Not sure what this is. Is it the warning (check engine) light is missing? It is on.

4) As per 2)

5) Cam Sensor - Is there a separate cam sensor as there is no inlet CVVT solenoid?

6) Emissions system leak - Minor. Will have to smoke the system possibly to find this.

7) TC - Turbocharger intermittent control system fault. Is this a faulty TCU? If so, need to see if I have a spare used one

Intake air leakage - Have to try the brake cleaner/WD-40 spray test or smoke the system.

9) Idle air trim : What/were is this??

10) Throttle valve - Faulty signal - If this means the ETM/Throttle body. It seems really oily, so will require to be remove and cleaned. The refit and see if the issue is still there.

There will still be the possibility of another issue that is not coded. If the cold rough start does not get fixed, may have to test/replace the ETC

So added to all the other issues, the work and cost to return this car to decent and safe condition could be a huge investment in time and money.

Neil.

i fixed #1 with an oil/filter change.
#5 cam sensors are on the driver side or transmission end of the cams,
sounds like some general air leaks someplace, smoke em out.
rough cold start is probably the upper o2 sensor heater failure.

[scot850]

Awesome, thanks for the suggestions and guidance. I believe the car is due an oil change as well. The CVVT valve is not hard to remove and clean. I think the owner changes the oil but likes to stretch the changes.

Thanks for the info on the cam sensors. I know the car recently had can seals done but not sure which ones. Maybe something did not get plugged in or seated properly. A quick look won't do any harm.

The air leaks I'm thinking are going to take some hunting out. I am suspicious of the ETM and pipe. I mentioned there seems to be a lot of oil on the inlet plastic pipe below the ETM. Not sure where it could be from unless is it the banjo bolt seals on the intake maybe?

As I was saying, other than the O2 sensor, maybe the rest are just needing cleaned or resealed for the most part. No point starting on that until we know what the owner wants to do as there is a fair list of stuff already. No point fixing the other stuff unless the safety stuff and O2 sensor are replaced first. Those alone will be in the $2000 CDN ($1500 US) even for budget stuff of a reasonable quality that won't need replaced again in a few months. Hate do-overs!!

No just waiting for my mechanic buddy to have time to confirm my findings (and hopefully not add too much, hopefully reduce!). Then I can talk to the owner.

Appreciate the help!

Neil.

[scot850]

Sorry volvolugnut, I almost missed your valuable help and input! Missed it at the bottom of page 1!! Sorry!

Both you and jonesg look like similar advice. I am thinking the same. Problem with just clearing stuff without at least doing some fault investigation, is that some of these issues may re-occur in a few or many miles. I'm one of those ding-bats that has to be sure an issue has been investigated and ideally cleared so my conscience will let me sleep!

I agree just take smaller bites and try and tackle each one, clear and see if it then returns. Sure some may come back, but at least there are less moles to whack!

I did do the glove test and it ran flat and rev'd it drew in slightly. I know the car had a new cam(s?) seals fitted recently as one was leaking, but don't know if the PCV was cleaned or not. Seems strange the seal blew out and now all is good on the PCV front if nothing was cleaned?
I may have to get the boroscope out tomorrow and take a look around the area of the ETM and see if there are any obvious leak sources which may pressure reduce a clogged system.

Again thanks to both of you! Awesome!

Neil.

[jonesg]

it really sounds like you are losing vaccum, it shouldn't need revving up to draw the glove down.
Cam seals can just plain wear out but I think it had some help with lack of sufficient vac.
I can monitor vac with my ELM327. Plus I have a vacuum gauge from IPD that sits next to the A pillar.
It shows 10 to 15 in/HG .

[lrock]

do the throttle body test in vida.
regarding length of time to get vida going, I just keep my vida VM paused all the time in the background, after choosing to run it as a disconnect able instance, uses virtually no resources in the background and is ready to go with two presses whenever I need it. you could also probably run it headless on a desktop and pipe it over your laptop whenever you wanted to plug in to the car. this just came to me, so i'm going to experiment with that.
does your 02 have the Bosch or the marelli? i've been raiding 02's lately and they've all had Bosch units. I have one still glued to the intake currently.

[scot850]

Thanks for the suggestions. Looks like a Bosch unit. Has Bosch part number on it, but can't see a Volvo part number anywhere.

I could run the various tests with Vida as you suggest. Looks like unfortunately it is a moot point. Sent the list to the owner and I reckon he has decided to pass the car on to a junkyard as not economic to fix. Shame but you have to make the call at some point. If I had $3000 kicking around and nothing but spare time I could take it on, but I don't like the XC70 seats (one of the worst I have sat on for a Volvo). Also if the car was maybe 100000km lower in mileage it might break even on value v's cost to repair. Again, only worth doing if I had thought of keeping it as a winter beater, and the seats were ok for my back (they aren't). I have plenty of other projects to be getting on with that I can't seem to get to!!

Neil.

[scot850]

Well this is back on as an exploratory process to see if we can fix some of the engine challenges. If we can clear most of those for relatively little outlay (like oil and filter change which is overdue, exhaust CVVT remove and clean) and are confident the engine is good, then the potential new owner is happy to take it on and fix the rest of the stuff with my help. He is keen and willing to have a go. So we shall see!

Neil.