looking for cause to a ch613 e7 coolant loss

[Okiki Olufokunbi]

hello. I have a 93 ch613 with an e7 engine, and has experienced coolant losses that eventually led to hydrolocking the engine after the truck sat overnight, after coolant was added in the morning prior to starting up. This is the second time it has happened in two weeks. The driver claims that he did not experience any overheating on both occasions

The first time it happened, the driver got the red light warning, and when he added coolant, the red light turned off. this continued until the truck was parked for the night, and then coolant was added in the morning prior to starting it. The engine hydrolocked and would not run until the cylinder head was removed and cleared of the coolant. After replacing the cylinder head gasket (which was thought to be the problem) the leak stopped for about 1 week. thus was without a loaded tanker

then it happened again, same situation except that the tanker was full.

i need some help with trying to figure out what is going on.

Is it possible to have a internal head gasket leak without overheating the engine? What could cause this? If it a gasket issue, what could be causing it to fail?

Are there other leak paths through which coolant can get into the cylinder?

i will appreciate any help i can get.

thank you

[felicello122]

Could be a cracked or leaking liner seal, i had a cat do the same thing after a new head and head gasket,i had a cracked liner and would leak overnite.

[Okiki Olufokunbi]

Thanks Fellicello122.

The head gasket was more damaged the this second time around than the first time. The vehicle had the road speed sensor out and there is currently speculation that the engine overworked and generated more heat because the ECM was confused. I am not quite sure this will cause the internal leak to develop , but only because I have never heard anything like this causing a potential overheat problem.

Although the dashboard temperature sensor did not see it, I think there was more localized heat on the engine block/head gasket area and I am trying to get a coolant system pressure test conducted. I will keep everyone posted on the resolution.

[staxx]

Could be cracked head ,between the exhaust valves is common . Engine wont always over heat just because its leaking internaly also cracked liners happen sometimes , from heavy scoreing of piston skirts or broken rings ,over fueling etc. . Cracked block from not cleaning out head bolt holes , and low liner heights all possabiltys.

[turckster]

If you're filling a cylinder with coolant it's not from a bad head gasket. A leaking head gasket will either dump coolant outside or inside an engine. To get into a cylinder the coolant would have to get past a fire ring. Most likely cause is cracked head or, possibly but most likely not, a cylinder liner. You would have seen the scoring with the head off. Now, I'm not saying the liner may not be the cause, just seen more cracked heads than liners. They don't tolerate heat so well.

If one head is cracked it would be best to replace both.