Hey guys,
Yes, I know the EGR system and associated fault codes have been well discussed and trust me I've spent hours online searching and watching videos but I have some specific questions that I have not been able to find answers for.
Background: I have a 2011 Hilux 3L D4D KUN26R with the 1KD engine. About 12 months ago I did an intake manifold clean and reassembled, all went well. A few days after the clean a check engine light appeared and has not gone away. No symptoms, no limp mode, the car runs perfectly. Code is P0400 - Exhaust gas recirculation flow malfunction. My mechanic suggests as this is the only code present the EGR valve itself is faulty and not allowing flow past it. I've taken the intake system apart and cleaned it multiple times and the valve moves freely. I've visually checked all of the vacuum lines and have strong vacuum at the brake booster. If I disconnect the battery overnight the code clears but always comes back after about 20min of driving.
Specific Questions:
- The EGR valve moves freely but took more force than I was expecting, how much force is typically required to move the valve? E.g. light pressure with one hand, fair force with 2 hands, full body weight leaning on it?
- I've tested the vacuum on the EGR valve lines and it is lower than I expected, how much vacuum should be present at the EGR at idle? Should it be the same as the brake booster?
- Would the cooler bypass valve have any effect on this? I recently pulled the whole thing apart AGAIN and found that the cooler bypass valve was seized, I thought this must be the issue so cleaned, got it moving freely and reassembled only for the code to come back after 30min of driving.
- I have disconnected one of the vacuum lines on the EGR at idle and if I block the line I can hear a slight whistle somewhere nearby, is this a vacuum leak or just the system under load?
- I've removed the vacuum actuator on the side of the EGR and connected it to a battery with a wire and multimeter and has 12V across it, is this a solenoid and should it click when connected to power?
Any answers or advice is greatly appreciated.
Thanks, Mitch