After a about 10 miles this morning as I arrived the engine seemed to be rattling from the front, stopped and checked the oil which was good, water level good as well, no sign of anything externally untoward so decided to get it home, the engine oil light started flashing after a while so I stopped and checked the oil again which was ok. The oil light seemed to come on when going down hill and went off on the up hill roads mainly but not all the time. Oil and filter changed a month ago and it has been running fine. Alternator is fairly new so don't think the rattle is that, it sounds like its coming from the front of the engine. Any ideas if a an oil light and front engine rattle are usually connected and what is the likely cause? Thanks, Murray.
Nothing internal, Last month I fitted a new thermostat, fan and just the oil filter and fuel filter, its been fine until today, I have the last P38 in the yard still so will swap the oil pressure sensor over just to see it that's the problem of the red light coming on. Just spent a half hour looking through the rave to see how it all works, do the belt tensioner idler bearings ever give out?
Yes and the arm it sits on cracks and flexes so the arm twists enough for the belt to rub and shred itself.
Or the crank pulley has a rubber damper that cracks and that can cause some vibration but not sure why hills would change it.
I cannot remember where the oil pickup is in the sump. Check RAVE. Could be something is up with that is it is at the back? An o-ring gone, perhaps?
Tried another oil sensor and just the same, it seems when the oil light comes the rattle starts, the oil pickup is at the rear of the engine from the Rave image. As the sensor is just one wire which I presume earths out at low pressure it could be a fault on the cable to earth so will see if I can find a manual gauge to double check.
Whip off the alternator belt and check all the pulleys including the Aircon pulley at the bottom of the engine. Check the water pump for play also. Any of these can rattle periodically or permanently.. 
Even the viscous fan bearings?
Even the viscous fan bearings?
Datatek
Well-Known Member
Rattles often come from the crank pulley vibration damper breaking up. However from your description, it sounds as though you really have low or no oil pressure. If I remember correctly, the oil pump is on the front of the crank and relies on the crank pulley being torqued up good and tight to provide the drive.
Good point my good man!
No oil pressure at all now, not even enough to reach the gauge I fitted, also went to move it a bit out of the way and no power steering so I think it may be the crank pulley damper rubber breaking up as you say and maybe the main crank nut has come loose. I took the belt off and checked the pulleys and idlers and all looked reasonable. No AC belt fitted for a while.
Datatek
Well-Known Member
Keep running it and you will have more than crank pulleys and and oil pump to worry about, the big ends and main bearings will be shot.
dubbleRR
Well-Known Member
Going up hill revs rise light goes out,if its an auto ,going down hill revs drop light comes on ...Had an oil pump relief valve spring fail on a frontera ,and a oil pick up pipe crack on another engine all brought light on .....,or a slack crankshaft pulley bolt on yoursor a failed oil pump
or a failed oil pump
brianp38dse
Well-Known Member
With no power steering and no oil pressure it sounds like the crank pulley is loose and losing drive to oil pump, the nut has to be done up very very tight.
Damn those pesky O rings.........
That is why i asked if had done any work like chains recently. Crank bolts do not come undone if torqued up correctly. But it does sound like this one has and he has lost the oil pump.
That f*cker is done up seriously tight.
Datatek
Well-Known Member
Or should be.
Removed the rad and parts in the front, the damper assy was just spinning loose, the bolt was loose but only by a touch so the pulleys were running more or less in line, removed the pulleys and the damper, the rubber looks to be ok.
The flange left in the engine was turning freely even when pushed in hard, on removal I see it has a keyway but there is no key in the crankshaft or its sheared off level, the manual shows a section of the engine and it looks like a woodruff key does this and the chain sprocket.
Stripped the one out of my old car just to make sure and that has a good fit on the key and is a nice fit. (The crankshaft bolt was very tight)
Not sure why it happened as the damper looks to be fine visually, to get into it and find the reason and rebuild looks to be a major job so its nagging at me that No3 P38 maybe done, I knew I jinxed it when the new spare key went perfect!
The flange left in the engine was turning freely even when pushed in hard, on removal I see it has a keyway but there is no key in the crankshaft or its sheared off level, the manual shows a section of the engine and it looks like a woodruff key does this and the chain sprocket.
Stripped the one out of my old car just to make sure and that has a good fit on the key and is a nice fit. (The crankshaft bolt was very tight)
Not sure why it happened as the damper looks to be fine visually, to get into it and find the reason and rebuild looks to be a major job so its nagging at me that No3 P38 maybe done, I knew I jinxed it when the new spare key went perfect!
Fitted the damper and pulleys back on today, could only tighten the crank bolt against compression as the key is gone but ran it for a short while to check if I had oil pressure and it was 68psi on high idle just after starting, I tried it later in the day and it was 65psi. So at least the oil pump is working and the engine sounded normal. I keep looking at the manual and the engine thinking I should give it a go and repair it, the only thing that worries me if the crank turns out to be damaged where the woodruff key fits.
Got to buy a cheap car ASAP as stuck here in the boondocks without one.
Got to buy a cheap car ASAP as stuck here in the boondocks without one.
Tightened against compression will not be anywhere near tight enough for prolonged use.
The woodruff key may have sheered off at crank surface.....I had this (on a 200 Tdi) and I managed to use a drift and hammer to slowly rotate the bottom half of the woodruff out of the machined slot. As it is a curved slot, carefully hammering on one side causes it to rotate up and out of the slot. A quick clean up and thankfully the slot was in good order and a new woodruff key was fitted.
