check injection/turbo problems

[kazgaz1]

well reposting this thread now.
hi dave, well i'm confused now then. according to the haynes manual and other info i have read on the net it does have a wastgate. the turbo is a garratt turbo. as i look at the engine from the front there is the vacuum above and to the rear of the inlet manifold. there is one hose that comes from this and goes across to the right hand side of the engine bay and down to the solenoid. it is connect to one connect labelled vac. there is another hose that then comes from the solenoid labelled out and goes back across the top of the engine and finishes into the top of the wastegate.
i watched the wastegate/actuator rod move by looking between the inlet manifold ducting. and i somehow managed to get my left arm across ad down to feel and to move it.
i did end up removing all the air ducting to the manifold and the egr valve ad the battery. turbo spins by hand very easy.
i have had the car 2/3 months, have been looking at some of the history, the engine is from a 2004 model f9q-800 i think. was stripped down ad rebuilt with new turbo and new clutch and new injection equipment. the only thing that doesnt look new and to honest looks grubby and old is the boos pressure solenoid valve which is located below the ecu near the battery on the n/s of the car.
it looks like it has some sort of what can only be described as a small aiir filter type thing on the side. no bigger than a 5 pence piece. its like a piece of sponge but looks totally soaked in oil or water.
so the turbo should react the same whether petrol or diesel, so in that case i dont think it has every been working correctly. as i said or think i said earlier should the actuator rod move as soon as the revs are applied or not? the reason ii ask is that at tick over it didnt move but as soon as revs applied it moves into the actuator away from the turbo-if that makes sense. so i was trying to understand if the turbo has a wastegate valve, then if it is moving as soon as revs applied then it wont be creating any boost will it?

hope that makes some sense. all hoses have been checked and appear ok. as does the intercooler as far as i can see.
spoke to renault and surprise surprise they have never heard of that solenoid being replaced, although they said they new what it was they recommend a replacement turbo... i think not!!
well speak soon dave and thanks for the help

gazkazgaz1

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Location: north east
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[chewbacker]

hi these turbos do not have a waste gate. the actuator rod is infact used to control the variable vane inside the turbo. this solanoid that you mention is part of the same system. the more vacuum detected by the solanoid from the intake manifold the ecu adjust's the solanoid to move the actuator rod changing the vane size either enabling the turbo to spind up quickly from low revs or spin faster at higher revs. the sponge filter you mention sounds fine. all it does is draw in air to adjust the vacuum from the solanoid to the actuator.
could i ask what problem you have as this appears to be a new thread starting half way though a problem

[kazgaz1]

hi chew...
i have recently discovered they dont have a wastegate and are in fact variable vane. this was also backed up by dave and lots of other threads i have read tonight..... so haynes manual is wrong!!!!
i checked the operation of the actuator and if what i have read is correct it moves "out" of the turbo when at idle and should gradually move in when revved ? if this is the case then either my actuator or the solenoid are shot! it never moved back in to the turbo, so im hoping it is that

gaz

[chewbacker]

i know that when the car is about to start the rod should have a quick self test style movement tomake sure it is in the correct position.
another problem you may incounter is that when revving the vehicle while still idle you do not produce the same level of exhaust gas and use less fuel and air then what you would with the engine under load while driving. it would also be fair to say that with all the sensors fitted to the engine,gearbox, and final drive the casr also knows that you ain't moving so the extra boost is not needed.

on a dci/tdi normaly if while driving the variable vane system or control system devolpe a fault the vehicle would go into limp mode as this would cause major fueling problems and boost problems. if you ain't going into limp mode i would presume this side of the turbo is working fine.

what is the problem that you are having to think this may be the cause

[kazgaz1]

hi, it does go into limp mode, no particular time or place of any other indication which i could put it down to. i had been having the ceck injection light and then limp mode. had it tested 2 faults present glow plug circuit and it stated wastegate solenoid malfunction. both haynes manual and other info i have been reading highligt the solenoid as the wastegate solenoid but as you pointed out and from what i have read it doesnt have one.
gaz

[chewbacker]

i would first check that the vnt rod is readjusting every time the car is started. you will need to get someone else to start the car while you watch the rod. secondly the boost pressure sensor could be at fault giving the ecu false info. the maf sensor could also be at fault but this can only cause under boost problems.
if your willing for some knuckle bleeding uncouple the actuator rod at the turbo end, it's held on by a little circlip. your should then be able to wiggle the vnt lever to check it's working freely. also removing the actuator from the turbo would allow you to test this for leaks.
you could save yourself alot of work if you can get a garage to hook it up to there computer to measure the boost pressure and fual pressure. if both of these check out to be ok it could be a ecu fault
please let me know what you find out

[chewbacker]

hi just read all your first thread.
i'm really thinking it is a boost pressure sensor.
google vw tdi limp mode and see if it sounds like your problem.
vw suffer from pressure sensor faults as have done some of these in my work

[kazgaz1]

yea, i think im running out of things to check. the actuator rod does move... i have moved it by hand and you can feel the spring acting against it. i have also read about the vw tdi , i was glad to be honest that they also suffer from this at least it means its not just the renaults that suffer.

[kazgaz1]

hi all, well spoke to one renault dealer and surprise surprise advised it was the turbo and they could replace it!!!
so rung another renault dealer and the parts man there stated- they sell loads of the solenoids and they cost £71.02 inc vat. so off to order one and will see if it cures the problem.
will update after i have fitted it

gaz

[tomalamix]

k...post when you have your results. i hope its enough

cheers

[kazgaz1]

yea so do i

[chewbacker]

everybody seems to think these problems are just a renault problem but we keep seeing the same problems coming up on other brands too.
the turbo in the f9q 800 is a garrat gt1749v and it is also used in golfs, volvos, nissians and many more. there is a way of checking the voltage and resistance on the solanoid, it's on the autodata cd that most garages use. i'm on holiday at the moment but when i get back to work i'l print it of and post it

[kazgaz1]

that will be usefull, enjoy your holiday
gaz

[kazgaz1]

well time for update........
changed the solenoid boost valve as they call it at renault....... Sorted at last.
no check injection runs brill and even better economy than it was before.
so to date i have changed fuel filter and the primer bulb to remove air in the fuel, changed glow plugs and finally the solenoid....
thanks for all comments and suggestions

for anyone wanting the boost solenoid.. part number is 8200486264 desritions is electrovanne

gaz

[tomalamix]

not so hard to find after an ECU scan, its easier to know where to start looking for the problem. glad you make it

cheers