I’ve been running into some recurring issues with my [car model]'s intake system and wanted to get some advice before deciding on my next steps. One of the main problems is frequent carbon build-up in the intake manifold, which seems to be affecting both engine performance and fuel efficiency. Despite regular cleanings, the build-up returns quickly, and I can’t seem to find a long-term solution. Another issue is that the airflow through the intake seems restricted, leading to a noticeable drop in power, especially at higher RPMs. I’ve checked for leaks and performed routine maintenance, but the problem persists. Additionally, I keep getting a check engine light related to the EGR system, even after replacing several components. The light eventually comes back, and I’m starting to wonder if the design of the intake manifold or something related to it could be causing these recurring issues. Before I consider making any significant modifications, I wanted to see if anyone else has dealt with similar problems and found an effective solution. Any advice or insight would be much appreciated!
Year?
Engine?
Code number?
Miles on the truck?
Then responders may be able to provide some suggestions.
Hi hasly123:
Welcome to the forum.
Despite regular cleanings, the build-up returns quickly, …
In addition to the details that Purebred asked above, can you also say a little more about how you’ve been cleaning the intake manifold?
Thank you.
2018 Ram 2500 with 6.7L Cummins Turbo Diesel I6.
P0300 with 60k miles
with mostly cleaner and scrub only
P0300 is not EGR related, P0300 is Random misfires
Bad fuel, Dirty fuel filter, Dirty fuel injectors.
Thank you for the information Hasly123.
I’m not a diesel guy, so I won’t attempt to answer.
There are some in this forum that will provide informed suggestions.
I had a similar issue on my 1996 Ford Windstar. The EGR return ports in the intake manifold plugged up and the dealer cleaned them 3 times. They finally recommended replacing the intake manifold. I asked them how simply replacing the manifold would solve the problem and they had no answer. My solution was to sell the minivan. It was 7 years old at the time I traded it in. I hope you find a different mechanic that can solve the problem. If not, replacing the intake manifold will only delay plugging up the EGR ports and won’t solve the problem.
You might post this on a Ram diesel forum, more likely to find somebody that has had this problem.
Is replacement a good option than what are good options for it? one of my mechanic friend suggesting spelab manifold kit…but i am nervous to do that
Here’s an example of a related discussion. Is your DEF system working correctly?
I expect the symptoms are all related. The EGR system outputs sump fumes into the intake manifold & is gunking up the intake manifold and probably damaging the turbo. The latter seems the most likely cause of your lack of engine power symptom. The DEF system mentioned above is probably damaged as well. It should be possible for a shop to clean out the EGR passages and the intake manifold, but depending on the internal inspection result, the turbo system may require replacement. The solution is just the normal shop inspection of all the affected system and doing the suggested work. The most critical part of the fix is to make sure the EGR valve is only opening when it should, and only to the specified flow rate.
I expect this is pretty common problem that eventually develops for most turbo diesels. So the upside is there should be plenty of experienced shops.
Does your truck use a NO2 sensor?
There is an Engine Control Module software update to correct erroneous P0401 EGR system performance faults.
Map Title 18-061-20 (nhtsa.gov)
When system faults are detected, the computer sometimes places the engine in a reduced power mode until the fault is corrected, this is normal so don’t be concerned with turbocharger failure.
Replacement is only a good option if the real problem is solved or if you will sell the truck soon and want to delay EGR port clogging as long as possible. It took a long time for the ports to clog initially and a much shorter time since then. That implies there is a reason not found yet for the problem.
Just to add to the above post, that is the difference between a parts changer and a real technician…
Many of us suggest using Google.
When I googled P0300 Diesel, none of the above fixes came up. No matter if Ford, GM, or Ram.
Would a typical consumer code reader would not read P0401 but would only return a P0300 code?
What am I missing?