VW Golf Mk2 Owners Club

running oil pressure up before starting after rebuild

September 21, 2020, 08:52:39 PM

I have rebuilt my 1.8 16v after a minimum rebore and head skim/guides etc..
Ive used loads of assembly lube, but I'm thinking of spinning it up without plugs to get the oil pressurised and distributed before I start it. 
It doesnt have an oil pressure gauge, so how do I know when it is up to  a decent pressure?  Do I a) wait for the tappets to stop clattering? That might take ages. Do I b) buy something to show me the oil pressure on a t-piece from the oil filter sensor (hey - another tool!), or do I c) just spin and wait for the light to go out.

If just relying on the Oil press. light, d)  how do I test it (and the sensor) work properly before I start, please? And e) how many batteries is all this likely to use before Im ready to stick plugs in and fire it up?

And f) should I wear a funny outfit and film it for 'youve been framed' to at least get the £250 back if it flies all to pieces?!

Thanks in advance.

Re: running oil pressure up before starting after rebuild

Reply #1 – September 22, 2020, 08:04:58 AM

Whenever I've spun an engine up post build, I usually just spin the engine for 60-90 seconds.
Providing the light goes out during that time, I'll either call it a day there, or give it another 30s spin for good luck.

I wouldn't wait for the tappets, you need to get some heat in the oil to calm them down. I usually find 15-30 mins of idling will quieten them down.

Also, don't forget to have a bloody good look around the head for any extra oil sensors that may not be plugged in.
Found that out the hard way when I emptied oil over my exhaust manifold!
Maybe give it a 10-15 second spin and have a hunt around the block for any signs of oil escape.
Then go for the full prime.

As long as your battery is fully charged, you won't have any issue spinning up the engine without plugs in.
There'll be no compression so it'll spin a lot faster.

Re: running oil pressure up before starting after rebuild

Reply #2 – September 23, 2020, 09:57:35 PM

I would also unplug the leads to the injectors stop them from filling bores with fuel.