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1981 Diesel Rabbit Oil Pressure Problem


'90 Escort Man
01-07-2008, 01:57 PM
Is the oil pump for engine run from the timing belt? I have a parked Rabbit that I am rescusitating, and it once had oil pressure, now none. Have plenty of clean, fresh oil. I noticed the timing belt is very oily and greasy. Also, is it possibly that it has a mechanical fuel pump driven from timing belt? I am trying to find the fuel pump, because I think it is faulty and not keeping fuel line pressurized for the i-pump. The car needs a shot of starting fluid after it sits overnight to get it running, but restarts immediately after shutdown.

Thanks for any help that you can provide!

zagrot
01-09-2008, 07:42 PM
the oil pump is driven from the counter shaft; the counter shaft pulley is the aluminum one below the diesel pump pulley on the timing belt, so yes, the oil pump is timing belt driven (it's location is below the vacuume pump on the inside of the block and it sortof hangs down into the oil pan). you may want to try cleaning the grooves on the counter shaft pulley if they are full of gunk; the grooves give any foreign matter on the back side of the itming belt a place to go so it can maintain traction on the pulley surface, sortof like how tire treads help with wet traction. if the timing belt is oil saturated plan on replacing it soon, if it is diesel saturated the front seal of your timing pump (and possibly the pump shaft bushing) is bad and/or leaking. if it is just oil then the front engine seals should be seen to (front crank seal, countershaft seal, or camshaft seal).

on a vw diesel there is no other fuel pump besides the bosche hanging on the front of the engine.

'90 Escort Man
01-10-2008, 10:17 AM
Zagrot, thank you very much for the info. The timing belt is fuel and oil soaked, I guess I am puking fuel out of the front of the pump and oil out of the front seal. With your reply, a bunch of things came together with my current ailments. I'm getting the service manual from the library this week, and get repairs in order.

Thank you again for your assistance!

zagrot
01-11-2008, 05:00 PM
any time,

since any seal replacement requires removing the timing belt read and make sure you understand the timing belt replacement procedures *before* you remove the timing belt. you'll need some special equipment to perform the pump timing procedure, but the most elusive is the dial indicator and indicator adapter (it screws into the end of the pump); all other tools can be replaced by common tools -- a deep socket to lock the pump and a 8" file to lock the cam shaft. if you have a set of calipers with a depth gauge you can use them, with great difficulty, to measure the pump lift -- but it is possible. alternately you can fine tune the injection timing by ear after you get it to run but it is a tedious trial and error process because it requires stopping the engine to move the pump and restarting (sortof like moving a distributor on a gasser, but it isn't advisable to do so on the fly).

about the front pump seal: it is possible to replace with the pump on the car by removing the pump pulley, and is easily done with the appropriate vw tool. it is possible to use the "screw and claw hammer" method as well, but there is little room to work between the wheel well and the front of the pump. if you remove the pump from the car you can possibly use a regular seal puller to remove the seal without marring the pump shaft. the problem with all of this is that if the pump bushing is worn replacing the seal will do no good (it might hold off the leaking for a little while, but not for long if at all) and requires disassembly to replace. the repair manual will give you a run out tolerance to use to check the shaft's play (lateral play; how the pulley moves from side to side) but the measurement also requires a dial indicator unless you can craft a jig and use feeler gauges -- read: severe p.i.t.a, but possible. anyway, if there is a fair amount of side play on the pump pulley with the belt off the bushing is likely worn. if you only need to replace the seal i can provide you a part number for a non vw seal that is commonly available, but you'll probably have to go to a seal shop to get it anyway, in which case you can take the old seal in for comparison and advise them it is metric and for diesel fuel use (in case they don't notice the smell!) and get an equivalent part.

hope it helps

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