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Redland1 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

Any idea where this leak is coming from? Pic is of the back side of the block.

marek4792 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

Left rear or right front is common for head gasket oil leaks. Possibly maybe leaking from elsewhere but running along the head gasket hard to know though.

tree98 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

Cam cover for the valve cam leaking and running down? Are you sure it's oil ?

Redland1 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

Here’s a couple of videos of the leaks the engine has.The one around the rocker cover and jake brake harness and exhaust manifold rear have been there for a minute.The one behind the engine is three weeks old,and the one at the top of the oil filter housing and front of EGR cooler is a week old.

https://imgur.com/a/WYBJ04s

tree98 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

Personally, none of those leaks would bother me in the least. Just looks like a little residue not oil spewing out and losing a gallon a week or something like that. Old engines are gonna leak a little, that's just the way it is.

Redland1 · 01-13-2023, **(Subject: Cm870 oil leak on what looks like the head gasket )**

(01-13-2023 )tree98 Wrote: Personally, none of those leaks would bother me in the least. Just looks like a little residue not oil spewing out and losing a gallon a week or something like that. Old engines are gonna leak a little, that's just the way it is.

Yeah it just sucks to see them because I prided myself on having an almost leak free engine.The rocker cover and engine brake harness were bad enough for me but it seems like this cold in North Dakota has made everything leak lol.

Magnat1976 · 05-07-2026, **(Subject: Cm870 oil leak on what looks like the head gasket )**

(01-13-2023 )marek4792 Wrote: Left rear or right front is common for head gasket oil leaks. Possibly maybe leaking from elsewhere but running along the head gasket hard to know though.

Hi Marek,i got leak on left side,seems from head gasket, what your experience on that?

Rawze · 05-08-2026, **(Subject: Cm870 oil leak on what looks like the head gasket )**

(05-07-2026 )Magnat1976 Wrote:
(01-13-2023 )marek4792 Wrote: Left rear or right front is common for head gasket oil leaks. Possibly maybe leaking from elsewhere but running along the head gasket hard to know though.

Hi Marek,i got leak on left side,seems from head gasket, what your experience on that?

It is not uncommon for the 870's to leak there a bit.

- This especially if some yahoo is always dumping the clutch hard, holding the thing to the floor on every single hill, and basically abusing the engine. - That or an after-garbage head/head gasket was used on it.

Leaky back corner of block.. and/or leaky flywheel housing = signs of engine being tortured repeatedly or driven exceptionally hard by someone (more than a few times) at some point in its life.

Magnat1976

(05-08-2026 )Rawze Wrote:
(05-07-2026 )Magnat1976 Wrote:
(01-13-2023 )marek4792 Wrote: Left rear or right front is common for head gasket oil leaks. Possibly maybe leaking from elsewhere but running along the head gasket hard to know though.

Hi Marek,i got leak on left side,seems from head gasket, what your experience on that?

It is not uncommon for the 870's to leak there a bit.

- This especially if some yahoo is always dumping the clutch hard, holding the thing to the floor on every single hill, and basically abusing the engine. - That or an after-garbage head/head gasket was used on it.

Leaky back corner of block.. and/or leaky flywheel housing = signs of engine being tortured repeatedly or driven exceptionally hard by someone (more than a few times) at some point in its life.

No a pleasant verdict...
Solution?possible overhaul in future?