Hi I have a Mk1 1.8 GTi (recently purchased) About 1000 miles after buying the car the oil pump failed - sadly it took the mains, big ends and thrust bearings with it. The top end was fine. Engine inspected, cleaned out and rebuilt by a garage I trust. About another 1000 miles - exactly the same again. Both events were sudden failure, the engine was making good steady oil pressure, warmed up and not under any particular load (modest revs). Both times the oil levels were good (just above midway). The second time the bearings all survived and have no damage at all. No evidence of metal shavings in the sump although the pump gears are munched (both times the same) - the gauze on the pump neck is intact and clean. I don't think the pump has eaten anything apart from itself. I don't know where the first pump came from - it came with the car, the second time I asked the garage to get a VW part. Is this a known problem? To be honest I am baffled, there is no obvious problem anywhere else, the engine runs sweetly. As I say oil pressure was good and also oil temps stayed well in check (I always watch both when driving). I am reluctant to put it down to bad luck/bad pump - I suspect there is a cause locked away in the engine somewhere. The only common feature (clutching at straws) was on both occasions I had just been around a right hand corner..probably a red-herring Thanks in advance
I wonder if the first pump failing (assuming seized briefly whilst gears mashed together) might have tweaked/bent slightly the drive "shaft" that connects it to the intermediate shaft/dizzy? If that was out of true, perhaps it could have caused the gear it drives directly to cavitate (wobble) slightly leading to the second failure. Don't know if that failure mode is strictly possible but it's certainly a uncommon situation you've had, so no harm in checking it out.
Isn't there a valve in the system that's often overlooked , that can get stuck , BrianG put up a detailed post about it before?
when i rebuilt my ABF i noticed a little restrictor screw kind of like a jet from a carb but bigger, had fallen out of the oil filter housing. it was just flapping around in there. correct me if i am wrong but 8v use same oil filter housing, and this little valve may somehow affect oil pressure? maybe worth checking?
Never liked the oil pressure tapping in the 8 or 16V engines. Picking it up on the cylinder head gives a lower pressure than seen by the crank bearings. I plumb mine straight to the top of the oil filter head, rather like a mini picking up the main oil gallery across the block. Gauges are so much better than a switch also. Jon
Did you find the problem? I have exactly the same problem with mi Golf gti mk1, the oil pump failed 5 times...
"5 times"!....never seen a pump itself fail, only bearings due to poor build/parts/starvation. Would be interesting to know who makes the O.E VW ones now...I doubt the volume sold warrants them being made the same as when they were new. I use either febi pumps or original O.E pumps if unworn. A friend in the trade had a series of failures with Ford Pinto pumps in F2 stock cars...he tried every aftermarket pump available and all failed at some point. He now only uses original used pumps and doesn't have pump failures anymore. K/S also make a VW pump...I've used those in the past without a problem to date too.
I know this is a very late reply. Mine is solved. Basically getting a genuine VW oil pump did the trick.
Thought the second one that failed as was a VW part? Still some debris floating around in there after the first failure I guess - glad it's all sorted very unusual for these pumps to fail.
Are you sure the pumps failed? How did you diagnose it being low pressure?. Febi/bilstein pump was around 70 from euro parts. Not had an issue. Stuck valves are the problem. Stuck closed (high) or stuck open (low pressure)
I had a problem when i changed mine, I had to drop the sump again and 'prime' the pump full of clean oil, then manually rotate the shaft to suck oil, refitted it and it was perfect, possibility?
On all these engines you can prime the pump using an electric drill and a homemade adapter down the dizzy hole Must be a good idea Jon
Strange one...The 'Right hand corner' thing, could have been a factor, if...the oil level was overly low. But It sounds like that can be dismissed. If a new genuine pump has done the trick, was anything done differently fitting wise? Priming as suggested above? It's enough to just pop the pickup in some oil and turn the shaft by hand until oil overflows, then tip a little out and fit. Really the typical febi, meyl pumps etc should be fine. If the pumps themselves ended up with knackered gear then it does point towards the pump having run dry for a moment or something. (They're pretty aggressively geared!) Would probably have to be pretty unlucky for that to be the case twice though! At least all is well now anyway Neil.
