v6Max 0 Posted June 25, 2008 Took my 1.9G plate to Brands today for a meeting which meant an hour or so on the motorway and there was some strangeness with the oil pressure: At a constant 70mph in 5th (3.5kish rpm) gear it varied from the middle mark and the 2nd mark on guage. No obvious reason it just kept moving around. When the pressure was down at the 2nd mark slowing down i.e. decreasing revs seemed to push the pressure back up again. Oil change was done about 100 miles ago and it's full of 10/40 Castrol GTX, new filter was also installed and I've just replaced all the breather hoses. About 2 weeks ago the pressure guage seemed to be jumping around and for a time showed full deflection i.e. maximum pressure. I had assumed that it was an electrical issue but maybe it wasn't and I've got something nasty going on with the oil system. I've checked the alternator pulley bolt and it's definitely tightened to the right spec. The other thing to note is that I've got drops of oil clinging to sump of the sump bolts specifically the area next to the flywheel cover plate. In addition a couple of drops of oil dripped from the g/box area and it looked suspiciously like engine oil. The question is: Assuming the guage wasn't lying, there was a high pressure "event", the thing that failed was the crankshaft oil seal but not completely could this explain both the drops of oil and the varying oil pressure? If not am I looking at dropping the sump and rebuilding or replacing the oil pump? Anything else I should check? Share this post Link to post Share on other sites
chrisj21 2 Posted June 25, 2008 Whats your oil pressure like while on warm idle? 205 oil pressure gages are notoriously bad so i'd try simple things like cleaning the wire connection to the sender or replacing the sender before dropping the sump. also do a search as theres plenty of topics on this chris Share this post Link to post Share on other sites
v6Max 0 Posted June 26, 2008 I've done those things... I think the next step is to fit a capillary type oil pressure guage and go from there. So does anyone know the block thread size so that I can order the correct adpater/fitting for a 3rd part gauge? Share this post Link to post Share on other sites
Tom Fenton 1,542 Posted June 26, 2008 Sounds to me like a classic case of bad wiring/connection to the standard sender, which as pointed out, is only at best a "guess-o-meter". Share this post Link to post Share on other sites
Grim.Badger 15 Posted June 26, 2008 Both of my pugs have done this, with different reading wierdness from different oils, so I doubt it is anything to worry about but if you are doing track days it is worth getting a mechanical guage just in case. Share this post Link to post Share on other sites
VisaGTi16v 1 Posted June 26, 2008 Did you actually recrimp a new plug on the end of the wire or just clean the terminal? I had a rock solid pressure gauge before but as the revs increased it smoothly dropped off to zero, let revs drop, it came back up correctly. Cue mass panic by me but I just recrimped the connecter and it was fine...must have had a clean connection but not enough current flowing or something. A standalone light and/or decent gauge is a worthwhile thing though Share this post Link to post Share on other sites
v6Max 0 Posted June 26, 2008 I recrimped the connection along with a bunch of other ones when I had the head off the car. I've got a Stack guage on it's way to me which hopefully will let me see if this is a real or virtual problem. I've got a suspicion that I've got "issues" with my loom - certainly at some point some one has allowed it to rest very close to the exhaust manifold resulting in the convulted tubing being melted in places. I've since moved it and this has cured some other things but makes me think I'm going to end up replacing the loom or simply bringing forward the GTi-6 transplant plans. Will see what the Stack guage has to say and then decide whether more investigation is needed but thanks everybody. Share this post Link to post Share on other sites
