FINALLY FINISHED THE REBUILD!...BUT

Posted: Mon Aug 08, 2011 9:35 am

At last the ACE is finished!
everything is nice and clean and just how it should look but when giving the engine a first outing the oil pressure starts to drop?
when cranking from cold the pressure guage moves over to 3.5 bar and as the engine warms up it gradually drops to 0.6 bar.On steady revs it builds to 2 bar or more at higher revs (3000+) but quickly drops back to 0.6 when idling.
The oil level looks correct and stays at 80 C and there are no noises from the engine,very smooth and quiet in fact and i have replaced the vdo sender for a new one (0-10 bar version),what is the problem?
The oil is Sainsburys own 10w40 semi synthetic(yes i know it wont be great but i am dropping it after 500 miles anyway,but it was in my garage)
Also the engine seems to get pretty hot reasonably quickly 90-100 c i know this is fairly normal but the fan comes on and off an awful lot (every 30 secs) when idling for a few minutes,is this normal?
Cheers guys

Posted: Mon Aug 08, 2011 2:55 pm

dont worry bout it, mines done it for the past 2 years exactly the same

Posted: Mon Aug 08, 2011 5:06 pm

should you not have used a thicker grade of oil for running in. Semi synthetic was probably a poor choice

from cold you should be seeing more than 5 bar. hot idle should see 2+ bar

Posted: Wed Aug 10, 2011 4:47 pm

and if you're interested I've got a brand new 10 Bar VDO gauge....

Posted: Wed Aug 10, 2011 10:03 pm

Seems this car doesnt want fixing!
having got it running it decided to spring water leaks from just about every hose opening on the car,then the seal on the temp sender went and finally the radiator developed a crack!
So it went for an mot today and guess what?
While on the ramp doing the emissions test it sprang an almighty leak from somwhere,which turned out to be a split hose to the oil cooler!
Happily it passed and left me trying to fix a leak outside the garage.
Anyway i am here to ask does it recommend that i use a different grade of oil when rebuilding an engine,should it be thicker to start with and change to a better quality after its run in?
your help once again is really needed chaps.

Audioc-only if its REALLY cheap

Posted: Thu Aug 11, 2011 7:19 pm

Yes, you should be using an oil designed for running in.

Definitely not a semi synthetic oil

Posted: Thu Aug 11, 2011 8:54 pm

What grade of oil do I need to put in

Posted: Fri Aug 12, 2011 10:14 am

http://www.bighealey.co.uk/content/classic-running-oil-30

Posted: Sat Aug 13, 2011 5:23 pm

Just wondering out loud, if the oil pressure is fine, but the new 0-10bar sender does not match the 0-5 bar gauge? Maybe try the old sender if you still have it?

Posted: Sun Aug 21, 2011 11:27 am

Hi scotty33 i think i'll try that next if i can find it.
I am really disconcerned about all of this as some of you will know through my previous posts in this engine rebuild,virtually everything was changed and all went together really well,my only hesitation was the intermediate oil shaft,the new shells went in ok but the shaft was quite a snug fit,but i presumed that a bit of wear would occur during the bedding in process,i have read that this can account for a poor reading in oil pressure if these bearings wear out?
another thing is performance,its very flat when cold and takes a bit of revs to get it moving (not too many revvs of course)when it gets warm its seems ok but i cant give it some stick until its ran in.i used a timing light on the vibration pulley/cover and whilst it lined up pretty much spot on every few seconds the mark moved way out of positon,the engine hesitated and then it would line up again.I put in a kr cam in the rebuild,would this account for the timing/hesitancy?
All in all the engine is quiet and seems really smooth,its just the oil pressure dropping when warm and the oil light comes on every time it idles at 80 C.

Posted: Sun Aug 21, 2011 10:06 pm

If the oil light is coming on, low oil pressure would seem to be genuine. I would change to more viscous oil, eg 15/50, this is less likely to leak away from the pressurised circuit, so should improve the oil pressure a bit.
worrying problem though and needs sorting out properly really, I don't know if there is a check valve, like in the 5 cyl lump, can cause probs, or a relief valve that may not be seating properly? Other than that it may be wisest to bite the bullet and check the intermediate shaft bearings

Posted: Tue Aug 23, 2011 9:06 pm

Well,i have changed the sender back to the 5 bar original and it has penrite running in oil (20/50 i think) and on startup i have a full 5 bar on the gauge.It stays around 3 bar when warmish and eventually goes to just over the 1 bar notch when operating at full temp and idling,it steadily goes up to 3-4-5 bar depending on the driving style which would indicate things are pretty good.Question is...what oil do you recommend once the 500 miles are up and the engine is bedded in?

Posted: Wed Aug 24, 2011 2:27 pm

If there is another grade of running in oil I'd use that for another 500 either 10W or 15W 50.

If not a mineral oil of similar grade to above.

I wouldn't switch to a semi synth until well after 1000 miles.

Driving style is also important. Don't sit at a cruising speed for a sustained period. You're supposed to work the engine and load up and down the box.

Posted: Thu Aug 25, 2011 8:44 pm

After it is run in, I would suggest the best oil you can afford! At the moment you have acceptable pressure at hot idle, so stick with something ending with 50. mineral oils are usually 15/50 but some synthetics com in 5/50 grades I think. Maybe browse Opie oils website for pointers and search for posts here by 'Oilman' - Guy from Opie oils?

Posted: Wed Aug 31, 2011 12:51 pm

How's a tenner plus postage sound?

Newbie Joined: Sep 07, 2011 Posts: 5

worrying problem though and needs sorting out properly really, I don't know if there is a check valve, like in the 5 cyl lump, can cause probs, or a relief valve that may not be seating properly? Other than that it may be wisest to bite the bullet and check the intermediate shaft bearings from cold you should be seeing more than 5 bar. hot idle should see 2+ bar