TheSamba.com :: View topic - oil leak type4 where does that oil come from?

Wed May 04, 2022 11:45 am

The oil is dripping of the air deflecter plates. The top of the engine is clean en the oil cooler looks also clean. There are some drips on the pushrod tubes but I don't believe that's the problem. On youtube someone explaning that the case bolts are lose, could that be the reason? Please help!

Wed May 04, 2022 12:14 pm

Start simple. Valve-cover gasket?

Wed May 04, 2022 12:44 pm

Probably the oil pressure sending unit if the leak started all of a sudden.

Wed May 04, 2022 1:18 pm

Those are both frequent and stubborn sources of leaks. Leakage in these places can look like lots of other things. I tried the fluorescent dye thing which didn’t help. Best way I found is to clean everything off, start the engine and check one place at a time with a bright flashlight.

Wed May 04, 2022 2:24 pm

05gh wrote: The oil is dripping of the air deflecter plates.

Clean everything under there (I use GumOut carb spray and paper towels).
If it is a fast leak, you can start the engine and watch.

Remember to test all the easy things like cleaning the valve cover gasket area and the push rod tubes right into the seal circles in the case and along the head.

The difficult cause of a leak in this area would be a loosened head that is allowing the cylinders to drain residual oil at shut-off. You would also see some soot around the cylinder spigots on the heads.

Remember air flow and gravity effects. Just because an engine looks clean along the top does not spare the oil pressure sender and cork gasket around the breather box and distributor o-ring ....
Colin

Wed May 04, 2022 2:55 pm

Amskeptic wrote: The difficult cause of a leak in this area would be a loosened head that is allowing the cylinders to drain residual oil at shut-off. You would also see some soot around the cylinder spigots on the heads.

I'd almost put money on this answer from Colin. Cylinder tops where they mate to the heads. The oil in the photo seems concentrated directly below this area.

Wed May 04, 2022 4:37 pm

Oil ends up in that area after it's been sucked up by the fan and blown there.

It get sucked into the fan which blows it across the top of the cylinders and then drips down.

Recently after fixing a bad oil leak I noticed oil in that exact place a day or so after. Residual oil that was still in the fan shroud and puddled in the fan was still making its way through to that spot.

That said, the pushrod tube seals are most likely to leak imo, so chances are that is where the oil is coming from.

Wed May 04, 2022 4:51 pm

AMC heads, that's where its leaking

Wed May 04, 2022 7:39 pm

Take a peak down at the top of your oil pressure switch. They tend to leak where the plastic joins to the metal of the body. Leaking is a very common failure mode for them.

Thu May 05, 2022 12:10 am

Vanagonsgoslow wrote: Probably the oil pressure sending unit if the leak started all of a sudden.

It was starting to leak more then avarage, first step I'll order and exchange the pressure switch.

Thu May 05, 2022 6:49 am

05gh wrote: Vanagonsgoslow wrote: Probably the oil pressure sending unit if the leak started all of a sudden.

It was starting to leak more then avarage, first step I'll order and exchange the pressure switch.

I usually put some plumbers tape around the threads. When installed, there will still be enough bare thread to ground the unit. It can also leak at the metal plastic joint.

Fri May 06, 2022 1:43 pm

Wildthings wrote: Take a peak down at the top of your oil pressure switch. They tend to leak where the plastic joins to the metal of the body. Leaking is a very common failure mode for them.

Update: Indeed de oil is dripping where the plastic joins the metal.

Fri May 06, 2022 2:43 pm

Looks like a fun one.
My spidey sense says check those pushrod tubes & O rings.
Remember the bus goes down the road & carries / sprays drips aftward.
Where are your bottom tins? Those can help show where it's coming from, if you are running them.

Mon May 09, 2022 1:15 pm

Replaces the oil presure switch, The oil was leaking where the plastic joins the metal and on the connector pin.

Tue May 10, 2022 11:38 am

05gh wrote:

Replaces the oil presure switch, The oil was leaking where the plastic joins the metal and on the connector pin.

Buy a few more to keep in the glove box. The newer ones like to fail often.

Mon May 16, 2022 6:34 pm

I replaced hat switch with the one from German Supply back in 2012. It is still running great leak free. Do not over-torque it.

Fri Mar 29, 2024 6:59 pm

Looking from the top of the oil pressure switch would I always see oil if the switch is the cause of a drip below it or can the oil seep out through the threads if not sealed right and one would never see it since the hex for the socket would be obstructing that view? I fished a long zip tie down right next to the switch and it comes out right where I see the most prominent source of oil (drips down through the cooler honeycomb). I have ordered a new switch and a deep socket since I don't have one in 24mm and I can then get a better look. Hoping it is as simple as the hex obscuring the leak. I suppose it could be leaking at the junction with plastic but no real evidence of that looking from top.

Fri Mar 29, 2024 7:25 pm

sun-bug74 wrote: Looking from the top of the oil pressure switch would I always see oil if the switch is the cause of a drip below it or can the oil seep out through the threads if not sealed right and one would never see it since the hex for the socket would be obstructing that view? I fished a long zip tie down right next to the switch and it comes out right where I see the most prominent source of oil (drips down through the cooler honeycomb). I have ordered a new switch and a deep socket since I don't have one in 24mm and I can then get a better look. Hoping it is as simple as the hex obscuring the leak. I suppose it could be leaking at the junction with plastic but no real evidence of that looking from top.

Also carefully check the backside of the cylinder head where the pushrod tubes are. You should not see the tube o-ring/s.

Fri Mar 29, 2024 7:38 pm

It can leak at both places

Fri Mar 29, 2024 10:21 pm

Note that a Type 4 takes a different switch than a Type 1. The Type 1 switch has straight threads and needs a gasket to get a seal with the block, whereas the Type 4 switch has tapered threads that do not require a gasket to get a seal.