Help on SC engine issue, please!

[Bob Kontak]

Originally Posted by AlexJ

for example at 2000 rpm 5 on oil pressure gauge.

Are you absolutely sure the pressure gauge reads 5? It should read 2 at 2000.

[AlexJ]

Originally Posted by Bob Kontak

Are you absolutely sure the pressure gauge reads 5? It should read 2 at 2000.

Yes, when engine starts - cold.

[AlexJ]

Originally Posted by woland

Alex, I read :

"I am now using 15W40 oil - quite cheap one..."

15W40 or 15W50 are ok but you shell use a decent mineral oil or semi-syntetic
I remember that more than twenty years ago my 5 cylinder Audi was ruined using cheap oil: When hot, the pressure was alvays very low, then the engine began burning oil from the exaust, then the car was good to trow away.
After this exeprience I always thought that an engine costs much much more than few gallons of good oil. I use motorcycle oil because bikes have much rpm than a sport car. I have no oil consumption and the engine always fires istantly

That sounds familiar! I am also starting to think oil quality has an important role on this issue...
Thanks for your help!

[AlexJ]

Originally Posted by SC-targa

Make sure the oil drain/screen cover on the bottom of the crankcase is installed in the correct orientation.

That is a good point! I remember that when I was posting pictures of the engine finishing work, someone made that comment - that I installed the drain panel not correctly... to be honest, I can't remember if I ever correct that... I'll have to check...

Thanks for your help!

[AlexJ]

Ok, now things a getting more clear, I think...

Bob, oil lines were taken out to clean and paint as well as the front oil cooler.

Tony, thanks for your comment. I will follow the recommended procedure on the next oil change.

I believe many causes might be involved on this issue.

Here is my plain:

- drain all the oil on tank, oil lines, full system.

- oil drain/screen cover on the bottom of the crankcase - just went to my garage to look and it is assembled toward the rear of the car...

- fit a Mahle oil filter ( I have been reading a lot about troubles other brands have been caused, I can't believe how I miss that!)

- fill with good quality oil following the procedure related above

... and after that, I hope to have reasons to stop thinking about a loose crank seal or broken piston ring that will ruin my budget on this project...

[Bob Kontak]

Originally Posted by Bob Kontak

Are you absolutely sure the pressure gauge reads 5? It should read 2 at 2000.

I am wrong on this. Sorry, Alex. Mine is about 4 1/2 at 2k rpm when cold.

Also looking forward to what you find out about the sump screen / drain cover. I don't fully understand why that may cause an issue but it must have something to do with the oil pickup (or not oil pickup if positioned wrong)

Keep us posted.

[Jdub]

I would avoid painting any oil lines and the trombone as well - they really only require a good scrubbing back to their copper finish. The reason is that paint (unless this paint has heat -conducting capabilities?) will only act as an insulation factor, retaining heat.

The 'off' plate and pickup is critical. You are starving the engine of oil if the plate is incorrectly positioned. The "top hat" sump filter was fitted to your car (by '82) if memory serves, and you may also have the updated oil pressure springs, parts number 911 424 70101 and 930 107 53101 (which I purchased for my '78 SC). Point is, people complained of high temps and hesitation when the car took a curve - the oil would swing away from the oil pickup mouth and grab mouthfuls of air instead.

So check this closely, unbend any wire defomation due to incorrect oil mesh installation, and reinstall, being sure to use fresh gaskets and nice even torque to prevent leaks.

Let us know how this progresses!

[AlexJ]

Wel... Apparently problem is solved.
Two rides already, great fun, and no smoke or strange reactions!

First of all, thanks to everyone who helped!

Photo taken after the first ride. Working temperature looks good, oil pressure normal reacting when accelerate, oil tank gouge showing it coming in when stop and the engine is at idle... and the engine sounds pretty good!

New oil fitted (Mobil 1 10W40 semi-synthetic), oil plug screen on the correct position, didn't change the filter because it was genuine and new, correct oil change procedure and, that's it! All working fine.

Now, next stage will be taking care of the cold start. CIS is not working as it should... Low idle, a bit back fire when I try to accelerate to warm up... Will see what I can do... But after it is hot, it runs well.

Thank you all, once again!