EGR problems

[magicarpets]

I have a 2006 6.0 bought in Feb 2011, 76k miles. Replaced the EGR valve twice in the last 6 months. Second time was just 3 weeks ago. Check engine light came on again last week and the local Ford dealership tried to tell me it was because MAFS sensor was contaminated by my AFE pro-dry filter. They cleaned it and reset the codes. Check engine light is back on today code P0402 (EGR flow excessive)

Going back in to the shop tomorrow. When I first bought it I was getting 16-18 MPGS, now about 12. Each time they replaced the EGR valve the MPGS went back up but dropped again after the check engine light came on. Truck is pretty much stock except for the AFE cold air intake and a Magna Flow cat back exhaust.

I am starting to think the dealership doesn't know what they are doing but the EGR valve repair is covered under warranty. I paid for the first one and they replaced it the second time at no charge. Otherwise I think I would take it to someone else.

Any ideas? I am really regretting buying this truck, never had a problem with my 7.3

Thanks

[justa03]

Depends on how the truck was treated before you got it. If the truck gets alot of idle time or did get alot of idle time the intake is probably all sooted/carboned up. Im hoping they are noticing if the EGR valve is excessivly dirty or even wet. When I see the intake is bad I generally take the intake out and clean it in the parts washer or have it sent to a machine shop and let them cook it to clean it better. Not sure if your dealership has BG but if they do there is a 6.0 EGR cleaning kit that seems to help. In my opinion when buying a 6.0 used expect some issues for a little while due to the fact you dont know what was done to the truck and they are kinda maint queens. Once you get the bugs worked out you will not regret getting rid of your 7.3, but then again that is just my opinion.

[SixStringMadness]

Welcome to the forum!

I was in you shoes about a year and a half ago. Bought a 6.0 (after two 7.3L), had lots of issues, (EGR and oil cooler related) but once the kinks were worked out, not an issue since.

If your EGR is sticking open due to getting fouled up, you could be in the early stages of an EGR cooler failure. Exhaust soot coming through the cooler, mixing with a tiny coolant leak, and gunking up the EGR valve. You'll also want to check for white chalky matter around the coolant degas cap.

This is actually a chain of faults, starting with the oil cooler.

Simple explanation, oil cooler stops flowing coolant, and in turn deprives the EGR cooler or adequate coolant for cooling, so the hot exhaust gases generate excessive heat within the EGR cooler and damage/crack the EGR cooler. Replacing the EGR cooler will not permanently fix the problem, you must also address the oil cooler. There are several options to consider, but first I would start immediately by monitoring the delta between you Engine Oil Temps (EOT) and your Engine Coolant Temps (ECT). A higher EOT than ECT indicates an issue, and a delta of 15° to 25° indicates a significantly blocked Engine Oil Cooler. You should do this while driving on the highway, level ground, steady speed for 15 to 20 minutes.

You can do this monitoring with an Edge Insight CS or CTS, or a ScanGaugeII (cheaper option)

This is a highly recommended MO for any 6.0 owner, even those with a completely stock vehicle.

FYI, I have a ScanGaugeII, EGR Delete, External Oil Cooler (OEM cooler delete) from BulletProofDiesel (BPD), and mild tuning and exhaust. 150k on the clicker, no issues, OEM head bolts/gaskets, truck runs away from my 7.3L's all day long.

[magicarpets]

Ok, so I just returned from the dealership and here is what they said:
The EGR dtc is being tripped because the Mafs sensor is fouled. The tech told me that the EGR valve is functioning properly, no problem with the EGR cooler.

He blames the entire problem (check engine light, poor fuel milage, etc.) On the AFE pro-dry cold air intake. He also told me that the engine has been "chipped" so it is not running on the stock program.

He recommends I remove the AFE air intake and install the OEM air filter and intake, replace the Mafs sensor, and flash the engine to the stock program.

In other words remove all the upgrades that have been done to the truck. (He said nothing about the exhaust) I thought the engine was running on a stock program and that the intake and exhaust were the only mods.

He claims that after market air intakes do not filter out enough particulates which fouls the mafs sensor and causes the EGR to read an excessive flow.

This totally goes against everything I have heard. I thought the whole point of upgrading the intake and exhaust and tuning the engine was to improve performance and MPG's.

AFE claims this intake is compatible and filters out 99.9 percent. They also claim to improve fuel economy. The also say it will not harm the turbo and the tech said it could. He essentially said that ALL aftermarket intakes were bad for the engine.

I mentioned that I never had a problem with my 7.3 and it had supperchips programing, K&N air intake and Bully Dog exhaust. But he told me that was only because the 7.3 had no Mafs, or EGR so you could "get away with it"
He said you just can't do it with a 6.0 without causing problems.

Anyway they want about $600 to restore it to stock. I am thinking maybe I should get a second opinion, any thoughts?

Thanks in advance.

[Northernl]

Find someone else to work on it. Dealership mechanics don't have any idea on how to fix vehicles. They look at a book and just replace parts until they get it working or you run out of money for parts.

[a2elvis]

I have personally seen AFE style air filter systems cause the EGR flow codes either insufficient or excessive. Put stock air filter assy back on truck and the codes went away for good. So it is possible for the aftermarket air filter setups to cause codes.

[F250SixOH]

Originally Posted by a2elvis

I have personally seen AFE style air filter systems cause the EGR flow codes either insufficient or excessive. Put stock air filter assy back on truck and the codes went away for good. So it is possible for the aftermarket air filter setups to cause codes.

Just an FYI but the stock air cleaner is good up to 500hp and is arguably the best intake for the 6.0 so don't be worried about any power loss with the stock intake

[SixStringMadness]

I don't know that I believe everything the dealer told you, but I am confident, unless you're making lots of power/boost, you cannot beat the stock air intake set up on a 6.0. If you upgrade the turbo, then upgrade the air intake. Otherwise the OEM air intake/filter is excellent.

[a2elvis]

Originally Posted by SixStringMadness

I don't know that I believe everything the dealer told you, but I am confident, unless you're making lots of power/boost, you cannot beat the stock air intake set up on a 6.0. If you upgrade the turbo, then upgrade the air intake. Otherwise the OEM air intake/filter is excellent.

Absolutely