Intake manifold temperature creeping higher

wolfe10 wrote:

lfeather wrote:


Thanks Don. I have the engine brake. Intake manifold temperature remains about the same when EB engages.

Larry

So, Larry which do you have, an:

EB= Exhaust Brake
OR
Engine Brake= Engine Compression Brake= Jake Brake

Engine brake...

lfeather wrote:


Thanks Don. I have the engine brake. Intake manifold temperature remains about the same when EB engages.

Larry

So, Larry which do you have, an:

EB= Exhaust Brake
OR
Engine Brake= Engine Compression Brake= Jake Brake

DSDP Don wrote:
"lfeatehr"...I was glad to see someone else monitors their intake temperature since Cummins doesn't look at exhaust temp. My 400 ISL always ran about 23-25 degrees higher than ambient temperature and never varied. My new coach runs about 30 degrees above ambient.

I don't know if you have an exhaust brake or engine brake, but I know when my exhaust brake was applied on my Monaco, the intake temperature would rise quite quickly. If you have the exhaust brake and it might be sticking a little.

Thanks Don. I have the engine brake. Intake manifold temperature remains about the same when EB engages.

Larry

Good point, Don. A sticking exhaust brake would sure drive up both intake and exhaust temperatures.

And, with Larry's engine (Cummins ISL), it could come with either an exhaust brake or engine compression brake).

Rising intake temperatures with exhaust brake on (throttle closed) is actually a reasonable AND good thing. With closed throttle, exhaust brake on, less air is moving through the system, so air stays in the ducting in the engine room long enough to pick up ambient heat. And, since there is zero fuel injected with throttle closed, it is not a bad thing that engine temperature does not drop suddenly. No point in exaggerating the heat/cold cycles in the mountains.

"lfeatehr"...I was glad to see someone else monitors their intake temperature since Cummins doesn't look at exhaust temp. My 400 ISL always ran about 23-25 degrees higher than ambient temperature and never varied. My new coach runs about 30 degrees above ambient.

I don't know if you have an exhaust brake or engine brake, but I know when my exhaust brake was applied on my Monaco, the intake temperature would rise quite quickly. If you have the exhaust brake and it might be sticking a little.

Personally, I think the air restriction gauge is useless. I owned my Monaco for almost 10 years and thing never really changed. You could reset it and it would immediately go back to the same spot after a hard pull, as stated above.

I know these air cleaners are expensive, actually cheaper on the Monaco's with the Donaldson replaceable element, but many seem to want to get 3-4 years out of them.

Many here will argue that theirs has lasted three, four, five years, but at what price to performance and at what risk of filter element failure. I use to replace my Donaldson on the Monaco every year which was about 12K miles and my coach always ran great and got good mileage. My new coach has the sealed unit which is twice the price and a pain to remove. I just changed it at 18 months with 15K on it.

Recently, there was a discussion on another site where I was labeled by two posters as foolish for changing my filters so often, even though it was my coach and my money. They argued I was giving bad info to others. My argument was that on the sealed units, it's hard to tell if it has failed. About two months later, another post surfaced where the OP had engine trouble because his sealed air cleaner had ingested water and he didn't know it. His was three years old. The other two posters quickly forgot their previous statements and suddenly were siding with changing more often. It's just not worth the risk on these big engines. We're also seeing more companies talking about shelf life and water ingestion causing element damage.

tempforce wrote:
the filter minder on my truck would only activate if i was under a heavy load.

Correct-- that is how they all work. They "store" the highest restriction and keep that reading until the reset button is pushed.

The highest restriction is always caused by the highest CFM demand by the engine. This is always at WOT at higher RPM's.

the filter minder on my truck would only activate if i was under a heavy load. such as a loaded trailer and passing on a grade... my mileage increased after replacing the element.. also received a boost in performance...

The air filter minder is easy to test. Pull the hose off the filter/pipe between filter and turbo. Suck on it. The indicator should peg at highest reading and stay there until you push the reset button. Reset.

BUT, you are absolutely correct, a high air filter minder reading is just one of the reasons for replacing the air filter. Remember, if the filter pleats have a crack in them (that is why you NEVER remove and bang a filter to remove dirt) the air filter minder reading will always be low.

Filters are made of paper. They degrade with time. Good idea to replace every three years whether they filter minder suggest a problem or not.