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  View original topic: I4 oil pressure problem & fix
Mike Pratola Wed Aug 20, 2014 7:28 pm

Late this March I picked up a 85 Westy with an I4 conversion done using a diesel van doner and an ABA short block / 1.8 head / digifant engine. I've spent the last few months of my spare time sorting out the wiring and intake, among many other little fixes. Last week I thought I was ready for the road, but the last thing I did before heading out to tag it was change the oil and filter. Used the proper Mann W719/5 and 15w-40, climbed in and fired her up, and got little to no oil pressure. After what seemed like a long time it did pick up and settle down to 25# at idle and 50 at 2500 RPM when hot, but when I went to start it the next day, nothing. I noticed the PO had left a quart and a half of NAPA 20w/50 synthetic in the cabinet, and the old oil looked like Hershey's syrup. I called the local VW guru whom I've been dealing with for years, and his answer was he has seen that before in the I4 engines, and just put the 50 wt back in. I knew there had to be a logical solution to this so I dropped the pan and pulled the pump. Backlash and axial play both checked out, and I could get the pressure relief valve to move, so I was still stumped. I put the parts in a box and went to see the local machine shop, where I worked years ago just out of tech school, and ran the problem by my old boss and friend. Without even looking at it he said 'Something's goofy with your pressure relief valve'. I told him I could move it, but he said 'Are you sure it's closing all the way?' We ground away the staking retainers and took out the spring, and sure enough the piston was sticking in the bore, and not traveling enough to seat consistantly. We cleaned up the bore with a small hone and polished the piston so it would easily slide under it own weight when you tilted the pickup arm. We weren't having much success at re-staking, so I drilled a hole through the area the spring retainer sits in and used a cotter pin to hold it in place. Reinstalled the pump, replaced the oil and fired it up. Oil pressure light went out immediatly, pressure went to 60# cold, took a short drive to get it hot and pressure at idle went back to 25#, 50+ at 3000 RPM, problem solved. Just thought I'd post this if anyone else is having an issue like this.

denwood Wed Aug 20, 2014 9:51 pm

Read this thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=580853
Would be helpful if you add your comments there :-)

The guys at Techtonics suggested checking as you did with prime issues. I also found much better oil pressure taking the end play clearance down to .003" as new, the pump end play was closer to .006". I'm seeing well over 1 bar/1000rpm (60psi@3000rpm, hot)... using 5w30 synth.



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