V70 D5 euro3 limp mode & engine service required

[anaml2]

Hia, looks like it could be the vains sticking in the turbo, i have done 8 turbo cleans and all worked and stopped limp mode apart from 1.

[Longhouse21]

Hi anam12,
I've had similar thougts so just extracted the turbo last night and about to start the inspection. However, first checks prior to stripping shows that the vacuum actuator is moving freely under applied vacuum and the actuator arm appears to go through full travel without any sticking or other problem.

[anaml2]

Hi, yes my did move well but i had done everthing else so thats why i took it of, i then could move the arm by hand and it was sticking one time and not the other aswell as feeling gritty, when you get it appart make sure the vains all sit nice and straight ive had 3 turbos with slight bent ones, easy to sort out though, best thing to clean it with is mr muscle oven cleaner but do not get it on alloy bits, good luck.

[Longhouse21]

Well the turbo has been taken off and stripped. Wasn't particularly dirty and still smooth in operation, but cleaned up and put back on and went for a test run. Still getting limp mode as demand placed on the engine. Seems to be revving a bit more freely but signs of hesitancy and best power comes on over 2k but runs out at around 3.5k, will run to 4k if I wait.

Time to invest in a vac gauge and run some tests through the vac system - just going on to Amazon to purchase.

So far, I've changed the turbo inlet hose (soft); cleaned the TGV (not particularly dirty, but that gave me the first increase in performance); cleaned the MAF (it was dirty, also saw an improvement in engine willingness to perform); checked for loose or damaged vacuum hoses (found a loose rear engine mount hose but made no noticable difference); checked the I/C hoses (no signs of iminent failure); stripped and cleaned the turbo (marginal improvement); fuel filter is new (car serviced around 500 miles ago).

I've not had the I/C pressure tested nor had a leak-off test on the injectors, so maybe that's the next step? Any recommendations around Warrington area?

However, I'm suspicious of the engine sensors used in the ECM calcs, particularly after the biggest improvement came from clening the MAF and TGV. Other than by substitution, how do I check the MAF(air flow & temperature), boost pressure sensor (mounted on the I/C) and the other sensors (water temp, engine speed, etc) used in the ECM calculations - I do own a multimeter so can check for volts, current and resistance.

Longhouse

[Longhouse21]

Latest update, carried out vacuum checks and got the following:

Vac pump at idle=0.68 - 0.7 -barg

TCV to engine mount, idle=0.7 -barg; 1000rpm=0.7 -barg; 1200=0 barg (instantaneous switch); 1500rpm & above=0 barg

TGV outlet, idle=0.68 -barg; 1000rpm=0.68 -barg; 1500rpm=0.65 -barg; 2000rpm=0.48 -barg; 2500rpm=0.44 -barg; 3000rpm=0.42 -barg; 3500rpm=0.41 -barg

Tried a run with TCV output to engine mounts clamped off, still getting "engine service required" message at around 3000rpm under heavy load, but car preforming well without obvious signs of dropping into limp mode

Tried a run after all the above tests (after taking the TGV off to fit the vac lines) and still getting the message however, I reset by stopping and turning the car off & restarting. The "engine service required" message didn't come up again and car performing fairly well under light loads & reving freely to 4000rpm, BUT when I tried again under heavy load / acceleration, got the message at around 3000 - 3200rpm.

I'm begining to suspect the TGV solenoid might be sticking, or are the vac figures OK, there appears to be the suggestion on some threads that it should back off, but it's a solenoid (on or off, not modulating?).

Could the boost sensor on the I/C inlet be the cause of the problem (possible over boost detected?) or is there something else I should be checking?

Any advice much appreciated before I dive out and buy a new TGV.

Thanks

Steve

[Longhouse21]

Sorry, should have added. In getting at the TGV again, I noticed that there was oil or wet deposits in the EGR outlet and I/C outlet pipe. It's not evident at the I/C but must be comming through the EGR valve as I cleaned it all less than 20 miles back,

Could the EGR valve be sticking and causing a boost or flow problem at elvevated rpm adn load?

Thanks

Steve

[gazza12345]

I am sure they have a square wave pulse. I changed me tgv last month & not had a problem since. I stipped the tgv down & 1 of the parts was worn out in it & making it a hit or miss if it held vacum. i have full stripdown pics but not uploaded them yet. The car now picks up from low revs brill & its torque in top gear is superb.

[outnumbered]

Originally Posted by Longhouse21

Sorry, should have added. In getting at the TGV again, I noticed that there was oil or wet deposits in the EGR outlet and I/C outlet pipe. It's not evident at the I/C but must be comming through the EGR valve as I cleaned it all less than 20 miles back,

Could the EGR valve be sticking and causing a boost or flow problem at elvevated rpm adn load?

Thanks

Steve

http://www.youtube.com/watch?v=Ij231VA3tX0

[Longhouse21]

Hi Outnumbered,
not sure what the link is telling me but the vac response I get is more like that on here but with steady vac at idle:

http://www.youtube.com/watch?feature...&v=nOJ50NJ-eQI

are you indicating that the EGR MAY be causing me the problem?

Steve

[outnumbered]

at idle you should be getting at the TCG at the block on the out port 25 hg as you press the throttle the vac should decrease as in the vid i put up is its not producing those figure then it could be faulty, there is a test on Vida to confirm if your TCG is working as it should, if it was the EGR it would show up as a fault .
mike