beschmidtke Report post Posted January 17, 2017 I am experiencing oil blow by with our Cummins ISC 350. This appears to be only happening while using the high stage compression brake. I try to keep the oil low by 2 quarts, but with a new dip stick that has not been calibrated, not really sure where I am at. Has anyone added a CCV to an ISC engine that was built prior to 2007 to help eliminate this problem? Share this post Link to post Share on other sites
wolfe10 Report post Posted January 17, 2017 Certainly, the next time you change oil, calibrate the engine oil dipstick. To verify that it really is blow by, hang an old coffee can or similar under the open crankcase vent hose. I have tried to wrap my head around how the engine compression brake could cause excessive crankcase blowby-- can't get there. Opening the exhaust valves at the end of the compression stroke allows compression to escape to the exhaust. If anything there would be less pressure past the rings than on normal combustion where you not only don't release compression, but also have combustion/explosion in the cylinders. Share this post Link to post Share on other sites
wildebill308 Report post Posted January 17, 2017 I think doing the retrofit of the CCV would not be cost effective. Like Brett says I would definitely install a catch can to your slobber tube. I used a 1/2 gal plastic bottle with a few holes drilled in the top to let the gasses out. Because you have been running without a catch can or extended slobber tube. Be sure to clean your CAC and radiator to prevent overheating this coming summer. Bill Share this post Link to post Share on other sites
beschmidtke Report post Posted January 20, 2017 Thanks for the responses. I did confirm the oil is from the slobber tube. Country Coach did let me know that if the oil is full, the compression brake could cause blow by. When Cummins installed the new dipstick tube and air pan seals, they did not calibrate the dip stick. I ran on low stage compression brake on a trip back from the Oregon coast and pulled a 1,000' pass with no new blow by. I just hate showing up at a park with oil dripping off my rock guard and all over our TOAD. Luckily I have a side radiator that stays fairly clean. Share this post Link to post Share on other sites
wildebill308 Report post Posted January 20, 2017 See my post above about installing a catch can/bottle. I used a 1/2 gal juice bottle drilled a hole in the cap for the hose to go in put a hose clamp on the hose under the cap so it won't slip out. also drill some vent holes to let the gases out, you do not want to create any back pressure. It was a lot cleaner under my coach after I did my catch can. Bill Share this post Link to post Share on other sites
jleamont Report post Posted January 20, 2017 Are you sure an ISC has a Compression brake? Can you snap a photo of the engine to include the valve cover? Share this post Link to post Share on other sites
wolfe10 Report post Posted January 20, 2017 12 minutes ago, jleamont said: Are you sure an ISC has a Compression brake? Can you snap a photo of the engine to include the valve cover? GOOD CATCH. We were all addressing the engine compression brake question without even considering the engine. The Cummins ISL is the smallest Cummins that can be equipped with an engine compression brake. You are absolutely correct, the Cummins C engine can NOT be equipped with an engine compression brake. It would have an EXHAUST BRAKE. And, yes and exhaust brake raises back pressure on the exhaust (basically like a potato stuffed in the tailpipe) and therefore crankcase pressure. But, a properly functioning exhaust brake (not producing excessive back pressure) with properly functioning engine should not produce excessive oil from the crankcase vent hose. Share this post Link to post Share on other sites
jleamont Report post Posted January 20, 2017 Its odd he has a stage one and two switch. I have heard of some odd things in the industry like dual exhaust brakes so seal it up tighter and I also read where they use the VGT turbo as stage one and the combination of the turbo and butterfly on the pipe as stage 2. But on an RV? beschmidtke what year make and model coach do you have? Share this post Link to post Share on other sites
beschmidtke Report post Posted February 1, 2017 My coach is a 2001 Country Coach Intrigue 40'. You are correct, it is a two stage exhaust brake with a switch to choose which stage you want to use. When I only use the low stage exhaust brake, I get no blow by. Second stage makes a considerable mess. I will be looking at the catch for the slobber tube. When I purchased it a year ago, we experienced no blow by on second stage. It began after Cummins replaced our dipstick and did an oil change. Cummins could not tell me for sure if they filled the spec 20 quarts, or kept filling to the full line on the uncalibrated dip stick. It is going back in for that to happen. Thank you for you responses. Share this post Link to post Share on other sites
dons2346 Report post Posted February 1, 2017 This is quite interesting. I also have an ISC ('02) and I have what I call a single stage exhaust brake. It is either on or off. Does that count for two stage? I do believe that the '01 and '02 were available with the ISL which in that case would have a two stage brake but it is not an exhaust brake but a real compression brake. During that time, Cummins put a red valve cover on the ISL motors, what color is yours? Share this post Link to post Share on other sites
wolfe10 Report post Posted February 1, 2017 Yup, the ISC could ONLY be fit with an exhaust brake (on or off). The ISL could be fit with either an exhaust brake (less expensive) or with a two stage engine compression brake. And, calibrating the engine oil dipstick so you are not overfilling the crankcase is the first order of business. Share this post Link to post Share on other sites
huffypuff Report post Posted February 1, 2017 Are you sure that you have a ISC engine in your 2001 Country Coach Intrigue? Maybe you can list the HP and we can tell your more. The ISC I believe max at 350 HP and is 8.3L. Better yet copy the model number from front data plate on engine. Share this post Link to post Share on other sites
jleamont Report post Posted February 2, 2017 Can you see the engine front cover? Should look like this if it's an ISL. My guess is it's an ISL 370 which is the entry HP for an ISL. Share this post Link to post Share on other sites
beschmidtke Report post Posted August 16, 2017 We are just on our way back from CO and experienced blow by again on my second stage exhaust brake. It is two stages with a three position toggle switch. I do have an ISC 350. The second stage exhaust brake is very aggressive. It will downshift with the RPMs going up to 2,400. I think 2,600 is the limit on down shifting. I try to keep it at 2,000 or lower. I had to use it on I70 heading East into Denver and I got blow by. First stage exhaust brake never gives me problems on RPM or oil. 2nd stage is nice to have in the mountains. Share this post Link to post Share on other sites
manholt Report post Posted August 16, 2017 Did you get your dip stick calibrated 6 months ago? Did you add a can or bottle to your slobber tube? Share this post Link to post Share on other sites
desertdeals69 Report post Posted August 16, 2017 My ISB has a accumulator tank on the slober tube and returns the oil to the engine. Its a 98 275hp and was made that way. Share this post Link to post Share on other sites
rayin Report post Posted August 19, 2017 Cummins Filtration sells a OCV oil filtration system that captures and returns oil to the engine. When I first read the pdf I was concerned about the "increase crankcase pressure" statement, but near the bottom of the pdf it states the pressure increase, the highest of which is 11" water column/near 1/2 lb. pressure. Share this post Link to post Share on other sites
rayherron Report post Posted December 2, 2021 I have a 2000 Country Coach Intrigue with an ISC-350 engine. The dipstick was replaced by Country Coach when the dipstick holder “melted,” it was made of a non metal material and CC replaced the sleeve and dipstick. I need a new dipstick and I am having trouble finding the correct part number on Cummins site. Could anyone help me with the correct part number? thanks Share this post Link to post Share on other sites
wildebill308 Report post Posted December 3, 2021 8 hours ago, rayherron said: CC replaced the sleeve and dipstick. I need a new dipstick Why do you need a new dipstick? Bill Share this post Link to post Share on other sites
manholt Report post Posted December 3, 2021 Bill, if inserted incorrectly they will break. Call Cummins with your engine # handy. Share this post Link to post Share on other sites
hermanmullins Report post Posted December 3, 2021 If I remember correctly, the engine manufacturer doesn't supply a dip stick for motorhomes. The manufacturer of the motorhome decides where it goes and supplies the dip stick. Herman Share this post Link to post Share on other sites
dons2346 Report post Posted December 3, 2021 My dipstick is metal and if you break it, you have a problem. In my case, Country Coach installed the stick, not Cummins. Reason being as Cummins has no idea how or what the motor is being installed in. The coach manufacturer makes a best guess about the length for install. That is the reason you should "calibrate" your stick. Put the correct amount of oil in and then mark the full level on the stick Share this post Link to post Share on other sites
