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#1 Series 2 oil pressure cure.

Posted: Sun Mar 22, 2020 6:55 am
by Badey
I had two failed engine rebuilds costing 9k by a so called "specialist " ,based near Exeter.
My original 4.2 engine was now basically scrap. Chewing up main bearings because the engine wasn't align bored, the bypass valve in the filter head had fallen out so unfiltered oil was being pumped around , grit and swarf in the oil ways, the crank plugs NOT removed and the galleries cleaned properly and to top it all, upper timing chain tensioners fitted upside down !!.
I totally rebuilt a sound series 1 xj6 engine and put that in, fitting my original filter head to it.
My original series 2 oil pressure relief valve was the smaller sealed canister type which is unavailable new.
The spring was really weak and could be pressed down with hardly any pressure. Oil pressure was just about ok but was below optimum when hot using 20/50 oil on a rebuilt engine .I bought a complete new spin on filter head fitted with a new pressure relief valve which is a different design to the weak one I had.
After some messing about I now have great oil pressure 45 at idle and 65 when on the move .
Because of my past experience, watching oil pressure really quickly decrease as my engine ate itself due to dodgy rebuilds I ended up watching the gauge more than the road.
It's been a steep and expensive learning curve that's for certain.
There some really great, kind people out there and a few rogues as well so beware.

#2 Re: Series 2 oil pressure cure.

Posted: Sun Mar 22, 2020 9:44 pm
by wwayman
What oil pressure gauge are you using to monitor your pressure?
Many have found the stock electric setup to be inaccurate.

#3 Re: Series 2 oil pressure cure.

Posted: Tue Mar 31, 2020 10:30 am
by mgman
After a complete engine rebuild my 4.2 engine struggled to display more than 40psi when cold. On a long continental trip it got down to about 5psi when hot in traffic. I found this very worrying, although looking into the cam cover plenty of oil was getting up to the top of the engine I assumed it likely there was plenty at the bottom. After driving like this for a couple of thousand miles to get home (anxious). I added a Mechanical gauge temporarily and all the oil pressure was there, 75psi cold start, 50psi hot running and hot idle 30psi.

I had prior to my long journey:
Replaced electric sender.
checkered 10 volt supply gauge.
Checked the gauge range.

I can only believe the replacement sender was suspect.