A Tale Of Two Oils...

[Anthony 1,003]

My 1.6 GTi engine has always been what I'd consider to be a good 'un (having driven a good few now) - it's the strongest standard 1.6 I've driven, good oil pressure, no smoke or oil/coolant consumption issues, economical, and starts/idles/runs properly.

 

I'd always used Total 10W40 semi-synthetic oil in it (and all my other 205's) and changed it every 4000 miles or so, and never had a problem. Last oil change however wasn't entirely planned (sump gasket failed and emptied most of the contents all over the road) so after replacing the sump and gasket I had to get some oil in a hurry from the local Partco - 10W40 semi-synthetic again and similar money, but somewhat of a no-names brand.

 

Oil pressure was a little lower on this oil, but only by a small amount (0.5bar or so) and well within the tolerance I'll give the standard gauges of being accurate, so I thought nothing more of it. However, over the few weeks since the oil pressure on this engine has progressively been getting worse and worse until I was sure that either the sender was up the swanny or the bottom end was about to expire. Hot oil pressure was pretty much in the red at idle, and was struggling to make 3.5bar at full revs.

 

With blatting round the track at FCS coming up at the end of the month I figured I ought to change the oil and once again went back to my usual Total 10W40 stuff. Even though the engine was stone cold, the old Partco oil poured out of the sump with the consistancy of water and not in the slightest bit "gloopy" as cold oil usually is - no fuel smell and certainly no mayo, so clearly down to the oil. Put the Total stuff in, and hey presto - engine is back upto full oil pressure again (1.5 bar hot idle and 5 bar hot @ 4000rpm) and has more oil pressure with hot oil than the Partco stuff was managing cold!

 

Just goes to show what sort of effect two apparently similar oils can have on oil pressure, doesn't it...?

[KRISKARRERA 2 1 Cars]

Yes. And I take it they were both the same standards on the back? You know the sae thingy.

[Rob_the_Sparky 10]

Had similar experience years ago with cheap oil although in this case it p*ssed out of the engine seals until we changed it for good oil at which point all the leaks stopped!

[aw11_hgt 0]

Wow - huge difference in quality - on a similar note do you know how fully synthetic fares in the gti?? (i.e. any drop in pressure etc)

[205007 12]

Oil is a bit like tyres really you get what you pay for IMO

 

i also had an oil pressure experience to forget with a pattern oil filter which brought the red light on after a good hammering

 

back to o.e and hey presto all is well

[KRISKARRERA 2 1 Cars]

My sump leak of 2004 got ALOT worse when I used Granville oil on one occasion.

I heard that many semi-synthetic oils are only 1% synthetic. I thought the word semi meant half??

[mattmk1 0]

My sump leak of 2004 got ALOT worse when I used Granville oil on one occasion.

I heard that many semi-synthetic oils are only 1% synthetic. I thought the word semi meant half??

 

 

I wonder if this is the problem with mine, it runs beautifully with no smoke, but the oil pressure on idle is just above the red. The minute you blip the throttle the gauge shoots up, and at 3krpm it sits roughly half way.

 

Im using granville oil at the minute, or is my pressure normal?