In March of this year I changed my 4K to a newly rebuilt 5K.

Since the beggining that I have intermittent oil pressure light when the engine is hot. It doesn't happen all the times, it does more when I push it a bit.

Changed oil pump, changed pressure sensor but it didn't solve my problem..

it only happens at idle speed, I usually pull the choke a bit to increase 50 or 100 rpms and it stops.

What can be giving me low pressure? I hear a "tac tac tac" noise when the engine is hot, it seems to come somewhere near the distributor and I was told that the this noise can be related to the low pressure issue...

Any help?

Thanks!

What lifters are in the engine - hydraulic or solid?

What lifters are in the engine - hydraulic or solid?

 

Hydraulic!

Maybe an oil feed to one of the lifters is partially blocked and when the oil is hot, a lifter is loosing pressure (just guessing)??????????????????

What viscosity oil are you using? Used to run 15w40 with no issues in my 5K.

I'd say a collapsed or locked lifter.

At first I was using 15W40 but changed to 10W40. It made no difference.

How do I check for a faulty lifter?

You don't, throw another on one - theyre cheap.

I was thinking of crankshaft bearings... Having to work my cranck and buy new bearings (around 150€) or buy a new set of lifters (24€+Tax each), don't know what's worse haha

Wouldn't a lifter problem give you an odd tappet gap?? Easy enough to check.

 

Can you push the lifter pistons down against the oil in a 5K?? In my old Armstrong Siddeley you pushed the pushrods right down by levering on the rocker with a big screwdriver, and set the tappet gap to 90thou. When you started it it rattled for a minute then settled down. Any jammed lifter showed up staight away.

 

For bearings you could take the bonnet off, lift the motor and drop the sump for a look. Pain in the arse job, but a little quicker than pulling the whole motor out and stripping it.

Have you changed the oil filter since the rebuild?engine change.

Could be a faulty oil filter.

If not, i'd put my money on bearings and worn crank.

Yes oil filter has been changed. I'll be checking the crank in a few days. Strange thing is this crank worked in my 4K for more than a year with no problems. But maybe the 5K rods and the new bearings didn't adjust as it should..

Cheap branded oils give a similar problem, get too thin when hot,

 

cheers!

I'm currently using ENI 10w40

I'm using Ashika 10-02-210 Oil Filter, does anyone know if this is a good or bad filter and if it can give me pressure issues?

I don't know that filter, but pressure issues would depend on where the sensor is.

 

Assuming the sensor is on the motor side of the filter and release valve, so it reads the actual pressure going around the motor, then when the filter is blocked it will read the pressure from the release valve. There might not be emough flow to keep the pressure up at idle, but its fine when the revs are up.

 

Can you fit an oil pressure gauge to it? If its 5psi below normal all through the range it would likely turn the light on at idle. The Girls KE70 has the light flicker on at hot idle if the revs drop below 1000rpm. Doesn't worry me as there is no stress on the motor at that time.