Club G40 Forum
Technical => Superchargers / G-Lader => Topic started by: g40chris on June 10, 2009, 11:11:47 pm
-
i have had the car back on the road for a week now and its been getting better to drive but that grinding sound is still coming as i put foot on accelerator under boost, there also seems to be a slight rattly noise coming from the charger area at idle.
should i take the charger off and see if the car still makes the sound. if not then its deffo the charger but i will be a bit gutted if its a bearing or scroll buggered as i bought the charger off here with the intentions of using it to run the engine in and doing a service on it when its run in and i know the engine is fine.
it seems to boost ok but the noise is so loud that it vibrates the floor
anybody know if this is a sign of a problem with the charger or if it could be something else
-
does it go away without the charger belt on? thats first thing i'd do (to rule out water pump, timing belt marker rubbing on crank pulley etc etc) and then check alternator bearings for play etc.
then it'd point to the charger
-
thanks
i will be trying it without the belts on later
i have a spare alternator which i can also try to rule out that
and i have a spare g40 charger casing with all the guts taken out so i can use on the car to tension the belts if i need to run the car without the charger for a while
-
well i have tried the car without the belts on and the sound has gone
so i was about to take the charger off when i decided to take the oil feed pipe off and check there was oil going through it, i had the pipe hanging out on the side of the car with the car running but no oil at all. so i decided to take the tee piece out and run the car with the hole open and oil does come out of the hole but not when the oil feed pipe is on, tee piece is clear, and i have even connected the oil feed pipe straight onto the hole at back of head but still no oil. but if i take the pipe off and blow through it is clear. i have even tried sucking it through just incase there is an air lock but i cant suck a golfball through a hose pipe as this is what it feels like. still no oil
is there anything im doing wrong and im sure this could be the cause of my grindy noises as it will be getting no oil into the charger
-
hmm sounds like so - the grindy may be warn bearings and therefore maybe some scroll wall on charger wall action!
oil feeds arent too dear - try replacing that
-
the oil feed is brand new from vw and i can blow through it but oil wont travel through it
i have a spare oil feed here aswel and this is the same
how much oil and what type of pressure should be coming through the oil feed when its not connected to the charger
-
You should be getting full pressure and oil pissing like a fountain. If you can keep your finger over the pipe end when the engine's running then it looks like your oil pump is the villain. Take it easy on the revs until you're sure.
-
i have managed to get oil to come through this now, linked it back up and it still made the sound. i changed the alternator and took it for another spin and its still the same. the only thing i have noticed is that there are 2 bushes on the engine mount that hold the alternator, mine only has 1 bush. the alternator is solid in place but im thinking that there may be a slight rattle because of this but i doubt it would make the amount of noise that the car is making. next job tomorrow is to take the charger off and put the dummy in place, if i still get the sound then i know my charger is ok. if not then i will jhave to strip the charger to inspect inside to see how much if damaged
-
oil was only dribbling out of the pipe, didnt even try to cover it with my finger.
i put a brand new oil pump on when rebuilding the engine. it was fitted by my mate a qualified vw mechanic
-
That's not right; I didn't tighten my oil feed up and lost a couple of litres over the engine bay, the drive and quite a bit of the garden within a minute.
-
oh dear
what else can cause low oil pressure
-
Some kind of internal leak maybe. Camshaft bearings not tightened down sort of thing. Oil goes where it gets the least resistance. Either that or internal blockage. Try blowing back through the charger feed point on the head with an airline.
-
there does seem to be some oil which has been leaking running down the cambelt side. will also look into this tomorrow
-
which oil sensor hole is this pipe suppossed to be coming from as mine was linked to the blue low pressure hole but is now linked into the yellow high pressure hole and works fine now. im just trying to see if this is sorted now or whether it should be in the low pressure hole instead
-
they usually connect to the hole closest to the cambelt end of the engine but it shouldn't really matter.
-
the grinding has stopped now
i will still try to find out why its a much lower pressure at the hole near the cambelt
-
what psi should these 2 oil pressure points be? so i can link a pressure gauge up to it and see where the problem is
-
Should be about 30psi on a fast idle when warm Chris. This story reminded me about your comment in the G/Eaton-which is better thread a couple of months ago. You suspected a blocked feed then. Looks like it's still with you.
-
yep i think i still have it
i will be blowing an air line down it this week as you suggested. so the pressure should be the same in both ports then. im deffo getting more pressure in the one which has yellow sensor on it.
-
i thought i would take some advice and put an airline in the oil pressure sensor holes, done this for about 5 secs in each.
but now i cannot get any oil pressure at all, i have even run the car without a rocker cover on and no oil is spitting out as it should.
my mate has told me that seeing as its a brand new oil pump that it may need to be packed with vaseline first otherwise it wont create a suction. if so could this be my problem
-
They new oil pump should need priming before use. Just like a syphoning action, there needs to be liquid in there already for the flow to start.
-
i spoke to my mate who fitted it for me and he said he filled it with oil
-
i am changing the oil filter just incse the filter is blocked at al
i have bought a new filter from vw and they say the filter is the same as the standard polo items, i have always thought that they were different and had a different micron rating
-
no g40 filters aren't different. I don't understand why your oil pressure warning light and buzzer wasn't kicking off if there's no oil pressure though.
-
i did have some oil coming through but not as much as it should be, but since blowing through the sensor holes with an air line there doesnt seem to be oil reaching the head at all. just changed the oil filter just incase it was blocked but still no oil. im starting to hate cars again, one thing after another. i know i will be happy when its all sorted but it just seems never ending at the moment.
will be taking the sump off today to see if the pick up is blocked
-
yeah but you need good oil pressure there for the light and buzzer not to sound, makes me wonder if someone has disabled the oil pressure warning system.
-
when i had the oil sensors out the light and buzzers came on. but now no oil comes through the holes at all.
the oil buzzer came on when i was driving and took it to 4000rpm for the first time
-
im struggling getting the sump off at the moment, dropped oil, taking all bolts holding sump in place off apart from 4 which are right underneath the driveshaft, exhaust and gearbox.
-
driveshaft needs to come off as does the exhaust downpipe. For the ones under the gearbox, if you remove the bottom cover (which has a single 11mm bolt in it) then you can see the back of the flywheel. If you have a standard flywheel then it has two cut outs in the ridge on it, rotate the engine by hand till these cut outs line up with the two sump bolts and you can just about fit a 1/4" drive socket on an extension bar up there. If it's a lightened flywheel then it's even easier because the ridge will have been machined off altogether!
-
i paid aw tracksport for a lightened flywheel but it looked standard when we rebuilt the engine. the only socket set i got is 1/2 drive no wonder im struggling
-
yeah I'd be surprised if a 1/2" drive socket will fit between the flywheel and sump pan. Get yourself down to halfords and buy a nice socket set with some 1/4" stuff in it, or borrow one off someone. The only other option would be removing the gearbox which isn't even worth thinking about!
-
1/4 socket set it is haha
i need one anyway as its easier to get into awkward places like this
-
i have taken the sump off and taken the pick up pipe off and cleaned it up as it was clogged. the oil had a shimmery metallic look to it, hoping this was crap from the rebuild.
i have blown an air line through the sensor holes again and also blown into where the cogs are by near the pick up pipe on the oil pump. i have blown through where the oil filter sits. blowing through the hole in the middle of the thread blows oil through and comes out by the cogs. i also have blown through the small hole at the bottom where the oil filter sits and it seems to blow through and oil comes out near the top of the diagonal pipe on the oil pump. should there be a gap by there.
-
If you're getting oil coming out of that area it sounds like the pump face isn't mating up correctly with the pump body;maybe worth removing and re-fitting. A leak here would explain low oil pressure. It's quite a critical area where they rely on good machining rather than gaskets. The oil pump's a self primer otherwise every time you cornered hard enough to cut the oil supply, you'd break the flow. Oiling/Vaseline/ Wynns etc. at start-up are just to stop any metal to metal contact until the pump is operational.
-
See you're looking for pics Chris. Does anyone have a schematic of the oil supply? that would help too.
-
well i vaselined the pump gears up, cleaned the metal mesh on the pick up pipe. refitted the sump, took the head off and blown through every oil way and water way to make sure they are clear. refitted head, fired it up. i have oil getting up to the tappets and cam, a small amount came out of the sensor holes but that stopped and hasnt came out of the holes again.
might have to take the sump back off and take the oil pump off as you said and re-fit if there is not supposed to be a gap there. but the gap is about 2mm wide