C7 Cat Oil Change...strange idle.

[Ncostello]

I changed the oil in our newest fire engine this past weekend. It was my first time using Low Emission CJ-4 Chevron Delo 400 LE.



It also happened to be the first oil change since its factory fill which I'm sure was CI-4+ since CJ wasn't out at the time it was built.



After starting and letting it idle for a few minutes, I raised the idle to 1200 and held it. It kind of surged or rather didn't have smooth idle. It was like I was pumping the foot feed up and down about 1/2". But I wasn't.



Then I took it on the road and it was down on power and still had the up down rpm going. More pedal didn't do much as far as more power/speed.



Then after about 3 blocks of this... it came out of it and runs fine now. Is this normal on a Cat C oil change? I know the injectors use oil pressure to operate. OR at least I thought they did. Its an ACERT engine.



Is this normal or is this related to CJ? Wish I had done a change using CI prior.

 

[HoleshotHolset]

D'oh!

Man - I'd really hate to think that an oil change would do that.



You're right - the ACERT engines still use HEUI injectors - which are fired with lube oil hydraulic pressure and commanded electronically. What a GREAT idea! They work so well for IH/Navistar!



Beers,



Matt

 

[Ncostello]

I called the local CAT equip dealer who also works on trucks. They said sometimes an air pocket will form and cause this. No harm will be done.



CAT manual recommends installing the filter dry. But I prefilled. My cummins ISC manual says prefill.

 

[JFaulkner]

Depends on how new the truck is because the new C7's are common rail. However HEUI works fine as long as you change your oil regularly and don't modify the system.

 

[JacobsD]

Depends on how new the truck is because the new C7's are common rail. However HEUI works fine as long as you change your oil regularly and don't modify the system.

And you change your oil to a lighter weight every time it gets cold.



Not my cup of tea, I'd rather stick to regular fuel pressure or electronic fired injectors.