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nathan88
08-19-2018, 12:50 PM
Ok so my 1.8t loses oil pressure starting around 3k rpm and regains it when i drop back down. My question is how dangerous is it for me to run it up to 4k or 5k just for a few seconds when accelerating. I plan on running the engine until it dies as it has 150,000 miles and (probably) bad bearings, but if going up in the revs is going to kill it immediately then id rather get a little more out of the car.

nathan88
08-19-2018, 01:21 PM
oil pickup and pump are fine and theres no knock either its very strange

Seerlah
08-19-2018, 05:26 PM
Check your pressure with a gauge. You can rent them at auto parts stores for free, and see if your pressure is in spec. Then go from there, because it could be a faulty switch or an underlying issue. If you can confirm you are in spec, then swapping the switch out for a new one should fix your issue. If not in spec, then further diagnosing sehould be applied.

nathan88
08-20-2018, 04:04 AM
mexhanical gauge reads the same as the sending unit...i think it is just a tired engine

walky_talky20
08-20-2018, 05:50 AM
The sending unit is just a switch...so the gauge will definitely tell you different information.

I think what Mitch was getting at is that we need to know the actual pressure you are seeing before we can tell you how careful you should be with the revs.

wolfe2118
08-20-2018, 07:30 AM
I had this same thing happen. I had a gauge connected after an clogged pickup screen repair. The sludge (I assumed) was causing the oil pressure relief valve to stick once the engine was making higher pressures again. As I would drive the oil pressure would eventually drop to zero until I would stop the engine and let the spring push the plunger closed again. I just changed the oil a few times and it's been good since. There is a very good write up on here about the 1.8T oiling system that clearly shows the oils path and the effects that a sticking oil pressure relief valve will have.

nathan88
08-20-2018, 11:13 AM
I dont have the exact numbers, but the pressure was within spec under 3k and dipped into dangerous levels after 3k as read by the gauge. Engine flushed and new pump still having the same issues.

Seerlah
08-20-2018, 12:38 PM
So you never dropped the pan to inspect the oil pick up tube screen? Engine flush can actually make your oil pressure worse on these vehicles. When it releases sludge and sediments in the engine, those eventually can make it's way to the pick up tube screen making it more clogged.

walky_talky20
08-20-2018, 12:42 PM
I had this same thing happen. I had a gauge connected after an clogged pickup screen repair. The sludge (I assumed) was causing the oil pressure relief valve to stick once the engine was making higher pressures again. As I would drive the oil pressure would eventually drop to zero until I would stop the engine and let the spring push the plunger closed again. I just changed the oil a few times and it's been good since. There is a very good write up on here about the 1.8T oiling system that clearly shows the oils path and the effects that a sticking oil pressure relief valve will have.

I was also thinking it could be a sticky relief valve.

nathan88
08-21-2018, 11:28 AM
Yes, I did the flush and that didnt help so i got a new pickup tube on there and its still having issues. Friend who builds race engines said it could be a bearing but theres no knock and it drives fine. I think I will pull off the oil filter housing and check the pressure relief valve. Ill keep yall updated thanks for the info.