My '53' block is leaking coolant

[Zoafan]

Whelp I think the coach we bought that has a 53 block ia cracked. I got home from our first trip with this new to is motorhome and saw coolant under the engine and my heart sank.

It looks like it is leaking to the right of where the oil filter mount is just below the upper radiator hose. I confirmed it is not the hose itself.

All I've found online says the cracks develope below the freeze plugs but mine is leaking way up and pretty much the front.

[RoyM]

Can't see much in the pictures but from your description I would suggest the water pump may be the culprit. Best to get the cooling system pressure tested, it is a simple procedure.

[RustyJC]

That doesn't sound at all like the "traditional" 53 block crack. These normally develop along the side of the block below the exhaust manifold where the casting wall would tend to be thinner than called for by the design. It's difficult to tell precisely where your leak is taking place, but don't rule out the seals in the thermostat housing/water discharge neck or the oil cooler. Those, to me, would be more likely sources in that upper front portion of the engine. Of course, a blown head gasket leaking to the outside is always a possibility as well, as is a leaking water pump seal.

Good luck with this one!! Since you said this was a "new to you" MH, do you have any recourse with the seller?

Rusty

[Zoafan]

If I use a mirror and look under I see allen screws with coolant signs.

The coolant stains are just under the exhaust manifold port closest to the fan drivers side.

[Zoafan]

Originally Posted by RustyJC

That doesn't sound at all like the "traditional" 53 block crack. These normally develop along the side of the block below the exhaust manifold where the casting wall would tend to be thinner than called for by the design. It's difficult to tell precisely where your leak is taking place, but don't rule out the seals in the thermostat housing/water discharge neck or the oil cooler. Those, to me, would be more likely sources in that upper front portion of the engine. Of course, a blown head gasket leaking to the outside is always a possibility as well, as is a leaking water pump seal.

Good luck with this one!! Since you said this was a "new to you" MH, do you have any recourse with the seller?

Rusty

Nope no recourse. Had the coach checked out twice and had all hoses and belts replaced.

Washed the area down and the coach has been idling for 20 minutes and I can't see any drips

[Zoafan]

Are there any gaskets directly below the housing where the upper radiator hose connects?

[HeapBigEngin]

Hard to say what it is. Any coolant in the oil? Any oil in the coolant? You said that you had the belts and hoses replaced AND that "it is not the hose itself". Not sure what that last part really means. Suggest you eliminate the easy things first rather than assume the worst. Double check the hose clamps for sure. Did the tech replace them along with the hoses? If not, that would be the first place I would look. Old, weak clamps tend to leak after extensive warmup. Also, not unusual for new clamps to need retightening after several hot/cold cycles....just the way it is. In any event, I would rule out the most obvious things first. After that, you could do a leak test yourself by cleaning the suspect area and then using a coolant dye and a black light (both of which are readily available at reasonable cost), running the engine at fast idle until and after the engine reaches operating temperature. You may have to take it out for a "spin" for the leak to show itself.

Certainly hope it is nothing more serious than the above. Please let us know how you make out....thanks!

[Skip426]

The 3 blocks that I saw with the cracks were all , mid engine and in the area of the frost plugs. From your discribed location , a leaking head gasket may well be the cause.
As mentioned in a previous post , a coolant system pressure test is in order. Overnight, through the cool down of the engine if necessary.

[Zoafan]

Originally Posted by Skip426

The 3 blocks that I saw with the cracks were all , mid engine and in the area of the frost plugs. From your discribed location , a leaking head gasket may well be the cause.
As mentioned in a previous post , a coolant system pressure test is in order. Overnight, through the cool down of the engine if necessary.

Can I do the coolant system pressure test myself?

[Zoafan]

Tried to use my automotive coolant pressure tester but couldn't get it up to pressure. Tested it on my car same problem so I'll pick up a new one tomorrow.

Washed the area with a turkey baster and let the coach high idle and no leak. Had wife press the gas and no leak. Took it on a quick freeway run and when I got back there was a leak. I cannot find out where it is coming from since I can't see overe there. It's to the left of the last exhaust port (towards fan) and right under the housing where the upper radiator attaches.

I cannot see that area, anyone know whats in that area I should check? I see allen bolts.

[RustyJC]

Before trying to get into much detail, since your MH is 1998 vintage, are we dealing with a 6BT (12 valve) or ISB (24 valve) Cummins? When trying to pull up images, schematics, etc., it's important to know which engine we're dealing with.

Rusty

[Zoafan]

Sorry it's an ISB 24v

[RustyJC]

The photo below shows the oil cooler location on the ISB. The flat plate to the right is the oil cooler cover. This oil cooler sits in the water jacket where it is exposed to circulating engine coolant. The oil filter (removed) mounts to the housing on the left.

The oil cooler is sealed to the block by a large formed seal that runs around the perimeter of the cooler-to-block joint. If this seal is leaking, coolant will leak around the cooler-to-block joint.

Could this be the source of your leak?




Rusty

[Zoafan]

Rusty

My oil filter is not located there. But rhat does not mean we are talking about different locations.

In rge picture you posted above I so not see the radiator hose.

My leak is directly under that housing.