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Oil Slick · 04-10-2021, **(Subject: Rusty Rockers )**

I adjusted the valves on my new truck 2020 KW X15 with 70,000 miles to find rust on the rocker arms. It does need coolant added about every 15-20,000 miles. This truck is a big house so the coolant runs through the sleeper, 2 heaters, hot water heater with heated fuel tanks. Several areas to loose coolant.

I need to get this truck in before the warranty is up. I’m asking for advice so I have more knowledge so they can’t BS me. What do you suspect is the cause?

Thank You

Rawze · 04-10-2021, **(Subject: Rusty Rockers )**

#1 cause is it sitting way too much at some point and moisture collecting under the engine cover. It is called lott-rott.

If it is in a motor-home, that is your problem right there... you gotta fire that thing up every once a week or so and let it get up to temp for a good 30-45 minutes and let it idle at 1000+rpm's.

those big engines do not like to sit.

Rawze · 04-10-2021, **(Subject: Rusty Rockers )**

(04-10-2021 )Oil Slick Wrote: ...
need coolant added about every 15-20,000 miles.
...

pressurize the coolant system to 20-psi and let it sit a while... fix all the leaks. You should not be loosing coolant.

Signature620 · 04-11-2021, **(Subject: Rusty Rockers )**

It could be losing coolant into the oil pan through a liner oring, badly fretted counterbore, bad head gasket, cracked head, etc. Then once the oil heats up and the truck sits, the moisture ends up in the top end.

Also very common to find rusted rockers on trucks that sit for long periods as Rawze said.

Oil Slick · 04-11-2021, **(Subject: Rusty Rockers )**

We run pretty hard but having a ARI Sleeper on it probably got stopped and started many times being moved in and out of the shop. Hopefully there’s a couple valves to shut off to keep the coolant from the bunk and test just the engine for leaks. If the pressure test doesn’t find a leak should the rocker arms be replaced?

Hope it’s not a liner O ring. Hate for them to tear into a good running engine.

Rawze · 04-11-2021, **(Subject: Rusty Rockers )**

(04-11-2021 )Oil Slick Wrote: ...
Hopefully there’s a couple valves to shut off to keep the coolant from the bunk
...

why would you have to shut that off? .. you should fine ALL the leaky points.

tree98 · 04-11-2021, **(Subject: Rusty Rockers )**

You should pressure test the whole system not just the engine area, you want to find the leak wherever it might be.

No those arms don't need to be replaced that surface rust won't hurt anything.

If I were you I would send in an oil sample to see if they find any coolant in the oil. That would be good to know sooner than later.

amermextrucker · 04-11-2021, **(Subject: Rusty Rockers )**

Hey guys quick question, would gear oil keep this from happening? given the fact how tacky gear oil is ? in a healthy engine ? i know if there is water intrusion then that would be a no.

Rawze · 04-11-2021, **(Subject: Rusty Rockers )**

(04-11-2021 )amermextrucker Wrote: Hey guys quick question, would gear oil keep this from happening? given the fact how tacky gear oil is ? in a healthy engine ? i know if there is water intrusion then that would be a no.

It does help keep that from happening to some extent.